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    posted Mar 4, 2011, 8:23 AM by rajesh gk

    Title

    Effects of applaud on the growth of silkworm (Lepidoptera: Bombycidae).

    Authors

    Vassarmidaki ME, Harizanis PC, Katsikis S.

    Laboratory of Sericulture-Apiculture, Agricultural University of Athens, Greece.

    Journal

    J Econ Entomol. 2000 Apr;93(2):290-2.

    Abstract

    An experiment was carried out to evaluate the effect of the insecticide Applaud (buprofezin 25% WP) on the silkworm Bombyx mori (L.). This insecticide belongs to the class of insect growth regulators (IGR). The larvae were fed on leaves treated with 3 different concentrations (0.5, 1, 2 g/liter) of Applaud on the 1st d of each instar. Analysis of data with the Tukey-Kramer test at 1% significant level revealed that mortality and larval duration did not differ among the treatments. On the contrary, the larval weight, which was estimated just before mounting (procedure during which the mature larva climbing on a branch or other material to spin the cocoon), differed among the treatments. Also, cocoon weight, shell weight, and cocoon sericin and fibroin content were different among the treatments, except the shell cocoon ratio. Maximum weight was observed in the controls and minimum in the last instar treatments. Our data suggest that supplementation of Applaud through food to larvae does not affect their mortality rate. On the contrary, it affects larval growth and cocoon parameters.

    Citation

    http://www.ncbi.nlm.nih.gov/pubmed/10826174 PMID: 10826174 [PubMed - indexed for MEDLINE]

     

    Title

    Purification and characterization of a protease degrading 30 kDa yolk proteins of the silkworm, Bombyx mori.

    Authors

    Maki N, Yamashita O.

    Laboratory of Sericulture and Entomoresouces, School of Agricultural Sciences, Nagoya University, Japan.

    Journal

    Insect Biochem Mol Biol. 1997 Aug-Sep;27(8-9):721-8.

    Abstract

    The second major yolk proteins, 30 kDa proteins (30kPs) of the silkworm, Bombyx mori, which have been provided during oogenesis, are kept continuously unused during embryogenesis and are utilized just before larval hatching. The crude extracts of newly hatched larvae cleaved 30kPs in an in vitro incubation system. A protease was highly purified from newly hatched larvae using ammonium sulfate precipitation, gel filtration and ionic exchange chromatography, and non-denaturing-polyacrylamide gel electrophoresis (ND-PAGE). The protease shared the NH2-terminal amino acid sequence conserved in many serine proteases, and the apparent molecular mass was estimated to be approximately 600 kDa by gel filtration column chromatography. The enzymatic activity was strongly inhibited by elastatinal and diisopropyl fluorophosphate (DFP), indicating that this protease is an elastase-like serine protease. The protease selectively hydrolysed 30kP-1 and 30kP-4 between Ser6 and Ala7, but could not attack other 30kPs such as 30kP-2, 30kP-3 and 30kP-5. Consequently, the protease characterized in the present study is a unique protease which may be specialized for the selective degradation of yolk proteins in silkworm eggs.

    Citation

    http://www.ncbi.nlm.nih.gov/pubmed/9443372 PMID: 9443372 [PubMed - indexed for MEDLINE]

     

    Title

    Cloning and expression of a novel gene encoding a new antibacterial peptide from silkworm, Bombyx mori.

    Authors

    Kim SH, Park BS, Yun EY, Je YH, Woo SD, Kang SW, Kim KY, Kang SK.

    National Sericulture & Entomology Research Institute, RDA, Suwon, Korea.

    Journal

    Biochem Biophys Res Commun. 1998 May 19;246(2):388-92.

    Abstract

    We differentially screened a novel gene encoding a new antibacterial peptide from the immunized Bombyx mori cDNA library. The gene showed a similar structure to that of cecropin-family, encoding 59 amino acids including a putative leader peptide and mature peptide. The deduced peptide, named Enbocin, had conserved amino acid residues which have been known to play an important role in the antibacterial activities. Enbocin genomic sequence revealed that the transcription unit of Enbocin gene was about 1.2 kb, and the coding sequence was interrupted by an intron of 660 bases. Recombinant Enbocin, expressed under the control of the baculovirus polyhedrin promoter, demonstrated a broad range of antibacterial activities against gram positive and gram negative bacteria.

    Citation

    http://www.ncbi.nlm.nih.gov/pubmed/9610369 PMID: 9610369 [PubMed - indexed for MEDLINE]

     

    Title

    Oxygen consumption in relation to sorbitol utilization at the termination of diapause in eggs of the silkworm, Bombyx mori.

    Authors

    Yaginuma T, Yamashita O.

    Laboratory of Sericulture and Entomoresources, Graduate School of Bioagricultural Sciences, Nagoya University, Chikusa, Nagoya, Japan

    Journal

    J Insect Physiol. 1999 Jul;45(7):621-627.

    Abstract

    Rates of oxygen consumption were followed throughout the entire period of diapause in eggs of Bombyx mori. In non-diapause eggs at 25 degrees C, O(2) uptake was divisible into three phases, corresponding to morphogenetic processes. In diapause eggs at 25 degrees C, O(2) uptake showed a peak (100 &mgr;l/g eggs/h) at 1 day and then suddenly dropped to reach a level of 8-10 &mgr;l/g eggs/h at 10 days and thereafter. To break diapause, eggs were exposed to 5 degrees C for varying periods. When O(2) uptake was measured at 5 degrees C, it remained at 6 &mgr;l/g eggs/h. When eggs were chilled for increasing periods and O(2) uptake was measured immediately after warming to 25 degrees C, the rates increased after a lag phase. In HCl-treated eggs, O(2) uptake increased immediately after acid-treatment. In all cases, highly increasing O(2) uptake at 25 degrees C coincided with termination of diapause. These results were discussed in relation to sorbitol utilization at the termination of diapause.

    Citation

    http://www.ncbi.nlm.nih.gov/pubmed/12770347 PMID: 12770347 [PubMed - as supplied by publisher]

     

    Title

    Reduction of glycogen in eggs of the silkworm, Bombyx mori, by use of a trehalase inhibitor, trehazolin, and diapause induction in glycogen-reduced eggs.

    Authors

    Katagiri N, Ando O, Yamashita O.

    Laboratory of Sericulture and Entomoresources, Graduate School of Bioagricultural Sciences, Nagoya University, Chikusa, Nagoya, Japan

    Journal

    J Insect Physiol. 1998 Dec;44(12):1205-1212.

    Abstract

    A new trehalase inhibitor, trehazolin, caused a potent inhibition of ovary trehalase in the silkworm, Bombyx mori. A single injection of trehazolin into pupae (40&mgr;g/animal) did not interfere with the accumulation of proteins and lipids, but markedly reduced glycogen content in eggs accompanied by a remarkable increase in hemolymph trehalose levels. The most potent effect of trehazolin was expressed in eggs that developed at the mid-stage of pupal-adult development. In these eggs glycogen content was reduced to a trace level, less than 3% of that of the control. The reduced glycogen content was almost restored to the control level by injection of glucose but not by trehalose. Trehazolin treatment influenced oviposition and larval hatching, whereas embryogenesis went on normally in glycogen-reduced eggs. Injection of synthetic diapause hormone into non-diapause type hosts induced an incidence of 45% diapause in the eggs and increased their glycogen content. Surprisingly, injection of trehazolin never affected diapause induction by the hormone, despite considerably reduced glycogen content in these eggs. Thus, our findings provide a new method for production of eggs containing various amounts of glycogen, and a novel system for analyzing diapause-associated metabolism besides the well-known glycogen-sorbitol metabolism.

    Citation

    http://www.ncbi.nlm.nih.gov/pubmed/12770320 PMID: 12770320 [PubMed - as supplied by publisher]

     

    Title

    Presence of eupyrene spermatozoa in vestibulum accelerates oviposition in the silkworm moth, Bombyx mori.

    Authors

    Karube F, Kobayashi M.

    Laboratory for Sericulture Science, Faculty of Agriculture, Tokyo University, Yayoi, Bunkyo-ku, Tokyo, Japan

    Journal

    J Insect Physiol. 1999 Oct;45(10):947-957.

    Abstract

    In the silkmoth, Bombyx mori, mating accelerates egg laying. Sterilized males did not induce females to oviposit, whereas artificial insemination was enough to accelerate oviposition. These findings showed that mechanical stimulation of the outer reproductive organs and the bursa copulatrix (BC) had no effect on oviposition. Factors included in seminal fluids also did not stimulate oviposition because neither implantation of female internal reproductive organs nor injection of the spermatophore extract into virgin females activated oviposition. Preventing sperm precedence by experimental removal of the BC or spermatheca inhibited activation of egg laying. More precise surgeries on the spermatheca showed that the main factor for eliciting oviposition was the presence of matured and fertile eupyrene spermatozoa in the vestibulum. Sperm were not effective unless they reached the vestibulum. Nerve transection and electrophysiological studies revealed that nerve 4 of the terminal abdominal ganglion was the pathway by which the mating signal was transmitted toward the higher central nervous system.

    Citation

    http://www.ncbi.nlm.nih.gov/pubmed/12770288 PMID: 12770288 [PubMed - as supplied by publisher]

     

    Title

    Fertilized eggs obtained from transplantation of frozen ovaries and parthenogenesis in combination with artificial insemination of frozen semen of the silkworm, Bombyx mori.

    Authors

    Mochida Y, Takemura Y, Kanda T, Horie Y.

    Institute of Sericulture, 1053 Iikura, Ami-machi, 300-0324, Ibarakiken, Japan. mochida@ss.silk.or.jp

    Journal

    Cryobiology. 2003 Apr;46(2):153-60.

    Abstract

    A reliable method is reported for the long-term preservation of ovaries and spermatozoa of the silkworm (Bombyx mori). Three studies are presented. In the first, ovaries were removed from larvae at either 3rd, 4th, or 5th instar, cryopreserved, and stored in liquid nitrogen. Thawed ovaries were transplanted to surgically castrated female larvae at the same or a different developmental stage. The highest percentage of recipient females producing eggs resulted into either 3rd or 4th instar larvae (respectively, 22.1 and 8.7%). Similarly, the highest levels of other measurements of successful cryopreservation and transplanted ovary, and number of eggs laid, occurred with the same combination of donor and recipient developmental stages. Other combinations of ovary/recipient developmental stages yielded lower results. In the second experiment, semen was collected from male moths, cryopreserved, and then thawed semen was diluted with trypsin solution and artificially inseminated into females obtained from the best conditions of first experiment. A small percentage of inseminated moths laid eggs (8-10.3%) compared to that of controls (100%). In addition, the fertility of eggs from experimental moths was lower than that of control females (respectively, 40.3-88% and 97.5%). In the third experiment, eggs were surgically removed from ovarian tubules of moth following transplantation of thawed ovaries and subjected to parthenogenetic activation and artificial hatching. As expected, all resulting moths were female and, following natural mating or artificial insemination with thawed semen, yielded normal offspring at high rates.

    Citation

    http://www.ncbi.nlm.nih.gov/pubmed/12686205 PMID: 12686205 [PubMed - indexed for MEDLINE]

     

    Title

    Changes in growth and lipid profiles of silk gland, mid-gut biochemical composition of silkworm, Bombyx mori L. on exposure to prostaglandin F2alpha.

    Authors

    Miao YG, Jiang LJ.

    Department of Sericulture, College of Animal Sciences, Zhejiang University, Hangzhou 310029, China. miaoyg@zju.edu.cn

    Journal

    Prostaglandins Other Lipid Mediat. 2003 Jan;70(3-4):331-8.

    Abstract

    The growth of the silkworm is influenced by the outside and inside environment. Among them, the category of various endocrine hormone of inside is the main factors that adjust the characters such as growth and propagate. In this experiment, we applied different dosage of prostaglandin to the fourth and fifth instar silkworm to observe the effects of prostaglandin F2alpha (PGF2alpha) on silk gland growth, mid-gut biochemical constituents and the lipid profiles of silkworm larva, Bombyx mori L. The weight of the posterior silk gland increased significantly (P < 0.001) by 20-24% after treatment with PGF2alpha. The increase in the lipid profiles except lipase activity suggests that the silk gland had more synthetic activity that might reflect in active spinning of silkworm larva. The changes of total proteins, free amino acids and alkaline phosphatase in mid-gut of control and PGF2alpha treated silkworm, B. mori L. indicate that PGF2alpha favored stimulatory effect on physiology of digestion, absorption and transportation of nutrients which might influence on the growth and development of larva.

    Citation

    http://www.ncbi.nlm.nih.gov/pubmed/12611497 PMID: 12611497 [PubMed - indexed for MEDLINE]

     

    Title

    Effect of prostaglandin F2alpha on gonadal carbohydrate metabolism of silkworm, Bombyx mori L.

    Authors

    Miao YG, Bharathi D.

    Department of Sericulture, College of Animal Sciences, Zhejiang University, Hangzhou-310029, China. miaoyg@zju.edu.cn

    Journal

    Prostaglandins Other Lipid Mediat. 2003 Jan;70(3-4):259-66.

    Abstract

    Effect of prostaglandin F2alpha (PGF2alpha) on carbohydrate accumulation in gonads of the multivoltine silkworm (hybrid: Xinhang x Keming) has been studied by means of topical application to larvae of the silkworm. Increased weights of larvae and reproduction organs, as well as carbohydrate metabolism in gonads of the silkworm, Bombyx mori L. was found after treatment with prostaglandin F2alpha. The increase in weight (larvae 21.9%, testis 28.9%, and ovary 33.3%) was associated with increases in the biomolecules (20-30%) and LDH and aldolase activity (18-25%). The results suggest that the accumulation of carbohydrates denotes a higher extent of utility of the energy sources in function of the testes and ovaries, and the routine application of prostaglandin F2alpha would be helpful in improving the reproductivity and egg quality of the silkworm.

    Citation

    http://www.ncbi.nlm.nih.gov/pubmed/12611491 PMID: 12611491 [PubMed - indexed for MEDLINE]

     

    Title

    Effect of fenvalerate-20EC on sericigenous insects. II. Digestive enzymes in the nutritive physiology of silkworm, Bombyx mori L.

    Authors

    Vyjayanthi N, Subramanyam MV.

    Department of Studies in Sericulture, Bangalore University, Bangalore 560 056, India.

    Journal

    Ecotoxicol Environ Saf. 2002 Oct;53(2):212-20.

    Abstract

    Changes in the activities of a few digestive enzymes after fenvalerate-20EC treatment were studied during the late stages of multivoltine and bivoltine silkworms, Bombyx mori. Insecticide treatment induced a reduction in the activity of such enzymes as amylase, sucrase, and protease, whereas the trehalase activity was enhanced when the midgut was used as the source of enzyme. The changes recorded in the activity of these enzymes indicated probable adverse effects of fenvalerate on silkworm metabolism through interference with the functional abilities of digestive enzymes.

    Citation

    http://www.ncbi.nlm.nih.gov/pubmed/12568456 PMID: 12568456 [PubMed - indexed for MEDLINE]

     

    Title

    Effect of fenvalerate-20EC on sericigenous insects. I. Food utilization in the late-age larva of the silkworm, Bombyx mori L.

    Authors

    Vyjayanthi N, Subramanyam MV.

    Department of Studies in Sericulture, Bangalore University, Bangalore-560 056, India.

    Journal

    Ecotoxicol Environ Saf. 2002 Oct;53(2):206-11.

    Abstract

    The effect of the common pyrethroid insecticide fenvalerate-20EC (Sumicidine-20EC) on food utilization parameters in the pure multivoltine (Pure Mysore) and pure bivoltine (NB4D2) races of silkworm, Bombyx mori, fed ad libitum with Morus alba, was studied in the final two instars. Insecticide treatment was found to reduce the rates of feeding, assimilation, and conversion along with the efficiencies of conversion of ingested and digested food into body substance. This was due to the toxic effects, which interfered with the silkworms' feeding behavior, and physiology of digestion, and the magnitude of changes increased with the increase in the concentration of fenvalerate used. To overcome the deleterious effects of such pyrethroid insecticides, it has been suggested that the safe periods for use of mulberry leaves contaminated with fenvalerate for summer and winter.

    Citation

    http://www.ncbi.nlm.nih.gov/pubmed/12568455 PMID: 12568455 [PubMed - indexed for MEDLINE]

     

    Title

    [Research on the artificial regulation of sex in animals in the USSR]

    [Article in Russian]

    Authors

    Strunnikov VA.

    Journal

    Ontogenez. 1978;9(1):3-19.

    Abstract

    The problem of artificial sex control was cardinally solved only for the silkworm among the domestic animals. The artificial sex control is realized by means of several methods. The artificial ameiotic parthenogenesis allows to obtain isogenic parthenogenetic progeny of only female sex. The meiotic parthenogenesis, on the contrary, gives only male progeny characterized by homozygosis by all genes. As a result of androgenesis with the participation of ooplasm and male nuclear material, only male progeny develops as well. Sex marked strains in which the female and male eggs are coloured in different may were obtained by means of translocation of the dominant genes controlling the egg colour on W chromosome determining the female sex. This allows readily to pick out the eggs of desirable sex only with the help of photoelectric equipment. The males of a specially raised strain balanced by two non-allelic sex-linked lethals, when being crossed with the females of any other strain, give male progeny only. The developed methods of sex control have found wide application in theoretical investigations of various directions and practical sericulture.

    Citation

    http://www.ncbi.nlm.nih.gov/pubmed/343027 PMID: 343027 [PubMed - indexed for MEDLINE]

     

    Title

    Exogenous prostaglandin F2alpha as a mediator in the regulation of silkworm growth and silk gland genome.

    Authors

    Miao YG, Nair KS.

    Department of Sericulture, College of Animal Sciences, Zhejiang University, Hangzhou-310029, PR China. miaoyg@zju.edu.cn

    Journal

    Prostaglandins Other Lipid Mediat. 2003 Nov;72(3-4):147-54.

    Abstract

    Prostaglandins are locally acting hormones that have remarkable variety of physiological functions. They are rapidly synthesized in several types of vertebrate cells as oxygenated metabolites of arachidonic acid in response to various stimuli. In many insect species they are biosynthesized in fat body and hemocytes mainly in response to bacterial infections. In the present study, we administered synthetic analog of prostaglandin F2alpha, the most prominent of the prostaglandins to the 48 h old fifth instar silkworm, Bombyx mori L. at a single dose of 4 microg per larva to study its effects on the larval growth pattern and silk synthesis. The possible role of PGF2alpha at altering the quantum of silk synthesis by controlling the silk gene expression was also studied. The genomic DNA was isolated from the posterior silk gland on Days 5 and 7 of the fifth instar from the prostaglandin treated and the control larvae and were random amplified with arbitrary primers. The result presented notable variation in the amplified product suggesting the participation of PGF2alpha in the silk biosynthesis controlling the silk gene expression. The feeding period of treated larvae was unaffected while the cocoon characters exhibited considerable improvement. The filament traits also were improved notably in the treated larvae. The participation of PGF2alpha analog in the silk biosynthetic process with its physiological and molecular implications are discussed.

    Citation

    http://www.ncbi.nlm.nih.gov/pubmed/14674626 PMID: 14674626 [PubMed - indexed for MEDLINE]

     

    Title

    A new chitinase-related gene, BmChiR1, is induced in the Bombyx mori anterior silk gland at molt and metamorphosis by ecdysteroid.

    Authors

    Takahashi M, Kiuchi M, Kamimura M.

    Department of Sericulture, National Institute of Agrobiological Sciences, Tsukuba, Ibaraki 305-8634, Japan.

    Journal

    Insect Biochem Mol Biol. 2002 Feb;32(2):147-51.

    Abstract

    A novel ecdysteroid-inducible gene was isolated from the anterior silk gland of the silkworm by mRNA differential display and named Bombyx mori chitinase-related gene 1 (BmChiR1). cDNA for BmChiR1 is 3.7 kbp encoding 1080 amino acids. Its predicted protein sequence consists of two tandem-repeated sequences, both showing high similarities to arthropod chitinases but lacking the active site glutamate essential for catalytic activity, suggesting that BmChiR1 protein has no chitinolytic activity. BmChiR1 mRNA was expressed simultaneously with chitinase mRNA in the anterior silk gland at the ends of the penultimate and last larval instar. Injection of 20-hydroxyecdysone (20E) into feeding last instar larvae induced accumulation of BmChiR1 mRNA. Topical application of a juvenile hormone analog, fenoxycarb, just after the 20E injection, suppressed this induction. BmChiR1 expression is therefore upregulated by ecdysteroid and downregulated by juvenile hormone.

    Citation

    http://www.ncbi.nlm.nih.gov/pubmed/11755056 PMID: 11755056 [PubMed - indexed for MEDLINE]

     

    Title

    Construction of a full-length cDNA Library from Chinese oak silkworm pupa and identification of a KK-42-binding protein gene in relation to pupa-diapause termination. Free PMC Article

    Authors

    Li YP, Xia RX, Wang H, Li XS, Liu YQ, Wei ZJ, Lu C, Xiang ZH.

    Shenyang Agricultural University, China.

    Journal

    Int J Biol Sci. 2009 Jun 24;5(5):451-7.

    Abstract

    In this study we successfully constructed a full-length cDNA library from Chinese oak silkworm, Antheraea pernyi, the most well-known wild silkworm used for silk production and insect food. Total RNA was extracted from a single fresh female pupa at the diapause stage. The titer of the library was 5 x 10(5) cfu/ml and the proportion of recombinant clones was approximately 95%. Expressed sequence tag (EST) analysis was used to characterize the library. A total of 175 clustered ESTs consisting of 24 contigs and 151 singlets were generated from 250 effective sequences. Of the 175 unigenes, 97 (55.4%) were known genes but only five from A. pernyi, 37 (21.2%) were known ESTs without function annotation, and 41 (23.4%) were novel ESTs. By EST sequencing, a gene coding KK-42-binding protein in A. pernyi (named as ApKK42-BP; GenBank accession no. FJ744151) was identified and characterized. Protein sequence analysis showed that ApKK42-BP was not a membrane protein but an extracellular protein with a signal peptide at position 1-18, and contained two putative conserved domains, abhydro_lipase and abhydrolase_1, suggesting it may be a member of lipase superfamily. Expression analysis based on number of ESTs showed that ApKK42-BP was an abundant gene in the period of diapause stage, suggesting it may also be involved in pupa-diapause termination.

    Citation

    PMID: 19785751 [PubMed - indexed for MEDLINE]PMCID: PMC2761947

     

    Title

    Annotation and expression of carboxylesterases in the silkworm, Bombyx mori.

    Authors

    Yu QY, Lu C, Li WL, Xiang ZH, Zhang Z.

    The Institute of Agricultural and Life Sciences, Chongqing University, Chongqing 400044, China. quanyouyu@126.com

    Journal

    BMC Genomics. 2009 Nov 24;10:553.

    Abstract

    BACKGROUND: Carboxylesterase is a multifunctional superfamily and ubiquitous in all living organisms, including animals, plants, insects, and microbes. It plays important roles in xenobiotic detoxification, and pheromone degradation, neurogenesis and regulating development. Previous studies mainly used Dipteran Drosophila and mosquitoes as model organisms to investigate the roles of the insect COEs in insecticide resistance. However, genome-wide characterization of COEs in phytophagous insects and comparative analysis remain to be performed. RESULTS: Based on the newly assembled genome sequence, 76 putative COEs were identified in Bombyx mori. Relative to other Dipteran and Hymenopteran insects, alpha-esterases were significantly expanded in the silkworm. Genomics analysis suggested that BmCOEs showed chromosome preferable distribution and 55% of which were tandem arranged. Sixty-one BmCOEs were transcribed based on cDNA/ESTs and microarray data. Generally, most of the COEs showed tissue specific expressions and expression level between male and female did not display obvious differences. Three main patterns could be classified, i.e. midgut-, head and integument-, and silk gland-specific expressions. Midgut is the first barrier of xenobiotics peroral toxicity, in which COEs may be involved in eliminating secondary metabolites of mulberry leaves and contaminants of insecticides in diet. For head and integument-class, most of the members were homologous to odorant-degrading enzyme (ODE) and antennal esterase. RT-PCR verified that the ODE-like esterases were also highly expressed in larvae antenna and maxilla, and thus they may play important roles in degradation of plant volatiles or other xenobiotics. CONCLUSION: B. mori has the largest number of insect COE genes characterized to date. Comparative genomic analysis suggested that the gene expansion mainly occurred in silkworm alpha-esterases. Expression evidence indicated that the expanded genes were specifically expressed in midgut, integument and head, implying that these genes may have important roles in detoxifying secondary metabolites of mulberry leaves, contaminants in diet, and odorants. Our results provide some new insights into functions and evolutionary characteristics of COEs in phytophagous insects.

    Citation

    PMID: 19930670 [PubMed - indexed for MEDLINE]PMCID: PMC2784812 Free PMC Article

     

    Title

    Repression of tyrosine hydroxylase is responsible for the sex-linked chocolate mutation of the silkworm, Bombyx mori

    Authors

    Chun Liua, Kimiko Yamamotob, Ting-Cai Chengc, Keiko Kadono-Okudab, Junko Narukawab, Shi-Ping Liua, Yu Hana, Ryo Futahashid, Kurako Kidokorob, Hiroaki Nodab, Isao Kobayashib, Toshiki Tamurab, Akio Ohnumae, Yutaka Bannof, Fang-Ying Daia, Zhong-Huai Xianga,

    Marian R. Goldsmithg, Kazuei Mitab,1, and Qing-You Xiaa,c,1+

    Journal

    Published online before print July 6, 2010,doi:10.1073/pnas.1001725107PNAS July 6, 2010

    Abstract

    Pigmentation patterning has long interested biologists, integrating topics in ecology, development, genetics, and physiology. Wild-type neonatal larvae of the silkworm, Bombyx mori, are completely black. By contrast, the epidermis and head of larvae of the homozygous recessive sex-linked chocolate (sch) mutant are reddish brown. When incubated at 30 °C, mutants with the sch allele fail to hatch; moreover, homozygous mutants carrying the allele sch lethal (schl) do not hatch even at room temperature (25 °C). By positional cloning, we narrowed a region containing sch to 239,622 bp on chromosome 1 using 4,501 backcross (BC1) individuals. Based on expression analyses, the best sch candidate gene was shown to be tyrosine hydroxylase (BmTh). BmTh coding sequences were identical among sch, schl, and wild-type. However, in sch the ~70-kb sequence was replaced with ~4.6 kb of a Tc1-mariner type transposon located ~6 kb upstream of BmTh, and in schl, a large fragment of an L1Bm retrotransposon was inserted just in front of the transcription start site of BmTh. In both cases, we observed a drastic reduction of BmTh expression. Use of RNAi with BmTh prevented pigmentation and hatching, and feeding of a tyrosine hydroxylase inhibitor also suppressed larval pigmentation in the wild-type strain, pnd+ and in a pS (black-striped) heterozygote. Feeding L-dopa to sch neonate larvae rescued the mutant phenotype from chocolate to black. Our results indicate the BmTh gene is responsible for the sch mutation, which plays an important role in melanin synthesis producing neonatal larval color.

    Citation

    http://www.pnas.org/content/early/2010/07/01/1001725107.full.pdf+html

     

    Title

    Purification and characterization of antiviral protein from silkworm fecal matter

    Authors

    Neelagund, S.E.*, Ingalhalli, S.S., Savanurmath, C.J., Hinchigeri3, S.B., Hiremath, M. B

    Journal

    Caspian J. Env. Sci., 5, 77-85. , ( 2007 ),

    Abstract

    Antiviral proteins (AVP), present in silkworm fecal matter, show activity against nuclear polyhedrosis virus (NPV) in vitro and in vivo. The extract of silkworm fecal matter prepared in phosphate buffer solution of pH 7.5 was subjected to 50% solid ammonium sulfate precipitation to enrich AVP, then which was dialyzed. The dialysate was applied to the column containing silica gel-G, the column elutes were purified by gelfiltration chromatography. The gelfiltration pattern gave three protein peaks A, B and C. The protein obtained from peak fractions of peak A is found to be active against NPV in vitro. Whereas the proteins were obtained from peak fractions of peaks C and B were not shown activity against NPV in vitro. The peak A fractions were collected and further purified by High Pressure Liquid Chromatography (HPLC) using C4 column. Purified AVP of SDS-polyacrylamide gel electrophoresis (SDS-PAGE) resulted in two protein bands with the molecular mass of 23 KD and 16 KD. Thymol sulphuric acid method of carbohydrate staining indicated that both of these protein bands are glycoproteins. AVP activity is determined in vitro by precipitation reaction. In vivo activity of the AVP is confirmed by conducting the bioassay in silkworms.

    Citation

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    Title

    Effect of VAM fungi and bacterial biofertilizers on mulberry leaf quality and silkworm cocoon characters under semiarid conditions

    Authors

    Ram Rao, D.M*, Kodandaramaiah, J., Reddy, M.P., Katiyar, R.S., Rahmathulla, V.K.,

    Journal

    Caspian J. Env. Sci., 5, 111-117. ( 2007 )

    Abstract

    The influence of VAM fungi and bacterial biofertilizer (BBF) with 50% reduction in the recommended dose of (N and P) chemical fertilizers on leaf quality traits of mulberry variety (S-13) and its impact on silkworm (PM ? NB4D2) growth and cocoon characters were studied under semi-arid conditions. Four different treatments were imposed i.e., T1: Control (only 100% NPK); T2: VAM (50% cut in P); T3: BBF (50% cut in N) and T4: BBF and VAM (50% cut in N and P). The results revealed that reduction (50%) in the dose of chemical fertilizers in T2, T3 and T4 did not affected the leaf quality traits or cocoon parameters, this may be due to the effect of microbial inoculants in these treatments, which had efficiently regulated the normal growth, metabolism and physiological activity in plants. Among the three-biofertilizer treatments, leaf quality, silkworm growth and cocoon parameters were found improved in T4 and was on par with T1 control. The dual inoculation (T4) proved economical and beneficial with regard to saving of 50 % cost of chemical fertilizers and improvement in soil fertility, leaf quality and cocoon parameters, thus this technology can be recommended to sericulture

    Citation

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    Title

    The Impact of Optimum Dosages of Mineral in Various Combination on Larval Development and Silk Production of Bombyx mori L.

    Authors

    Muhammad Ashfaq ; M.A.Rehman ; Amjad Ali

    Journal

    Pakistan Journal of Biological Sciences Year:2000, Volume:3, Issue:9, pages/rec.No:  1391-1392

    Abstract

    Optimum elements dosages i.e., 0.2%, 0.3%, 0.1%, 0.1%, 0.15% and 0.5% of various minerals i.e., N, P, K, Ca, Mg and Cu respectively in various combinations were studied on larval development and silk production of Bombyx mori L. The rearing of silkworm larvae was restricted to chopped tender and green mulberry leaves treated with different concentrations. The results revealed that mineral nutrients have not affected the yield component significantly but have also presented better food consumption, body weight, co- efficient of utilization and larval development as well. However, of all the test treatments T11 where the offered mulberry leaves were treated with 0.2% N + 0.3% K + 0.1% Ca + 0.1% P + 0.15% Mg + 0.5% Cu concentration gave the best results.

    Citation

    FULL TEXT

     

    Title

    Nutrigenetic Traits Analysis for the Identification of Nutritionally Efficient Silkworm Germplasm Breeds

    Authors

    C. Suresh Kumar ; A.K. Goel ; S.V. Seshagiri ; S. Sugnana Kumari ; H. Lakshmi ; C. Ramesha ; C.M. Anuradha

    Journal

    Biotechnology

    Abstract

    In order to amalgamate the effects of nutrition and its efficiency on genetic traits expression in silkworm germplasm breeds by serial analysis on nutrigenetic traits and utilized as biomarker with an aim to identify nutritionally efficient silkworm germplasm breeds. In the present study, six bivoltine silkworm breeds were subjected for investigation on ingestion, digestion and utilization of dry food matter in single silkworm larva and its sharing on economically important stages larva, cocoon and shell weight in 5th stage. It was resolved that low consumption with high conversion efficiency of food ingested in silkworm breeds on nineteen nutrigenetic traits analyzed by standard gravimetric method with the aid of INDOSTAT software to understand the nutrigenomic divergence among the silkworm germplasm breeds against different seasons. Results indicated that higher conversion efficiency was observed in most of the new silkworm breeds for Efficiency of Conversion of Ingesta (ECI) to cocoon and shell than control (APS8) as leaf - cocoon and leaf-shell conversion are the ultimate indices in nutrigenomic analysis. It also demonstrated that relatively smaller amount of Consumption Index (CI), respiration, Metabolic Rate (MR) with superior Relative Growth Rate (RGR) and in relation to quantum of food ingesta and digesta requisite per gram of cocoon and shell found less than the control. This concluded that nutrigenetic traits directly associated to the quantum of food ingesta and digesta g-1 of cocoon and shell and such nutrigenetic study pragmatically utilized as biomarkers in order to advocate sturdily the following breeds viz., RBD1, RBD4 (peanut type cocoon), RBO2, RBO3 (oval type cocoon) were chosen as highly nutritionally efficient bivoltine silkworm germplasm breeds.

    Citation

    FULL TEXT

     

    Title

    Expression profile of cuticular genes of silkworm, Bombyx mori

    Authors

    Liang Jiubo ; Zhang Liang ; Xiang Zhonghuai ; He Ningjia

    Journal

    BMC Genomics, 2010

    Abstract

    Background: Insect cuticle plays essential roles in many physiological functions. During molting and metamorphosis tremendous changes occur in silkworm cuticle where multiple proteins exist and genes encoding them constitute about 1.5% of all Bombyx mori genes.

    Results: In an effort to determine their expression profiles, a microarray-based investigation was carried out using mRNA collected from larvae to pupae. The results showed that a total of 6676 genes involved in various functions and physiological pathways were activated. The vast majority (93%) of cuticular protein genes were expressed in selected stages with varying expression patterns. There was no correlation between expression patterns and the presence of conserved motifs. Twenty-six RR genes distributed in chromosome 22 were co-expressed at the larval and wandering stages. The 2 kb upstream regions of these genes were further analyzed and three putative elements were identified.

    Conclusions: Data from the present study provide, for the first time, a comprehensive expression profile of genes in silkworm epidermal tissues and evidence that putative elements exist to allow massive production of mRNAs from specific cuticular protein genes.

    Citation

    FULL TEXT

     

    Title

    The Impact of Optimum Dosages of Mineral in Various Combination on Larval Development and Silk Production of Bombyx mori L

    Authors

    Muhammad Ashfaq ; M.A.Rehman ; Amjad Ali

    Journal

    Pakistan Journal of Biological Sciences (2000) 3 (9) 1391-1392

    Abstract

    Optimum elements dosages i.e., 0.2%, 0.3%, 0.1%, 0.1%, 0.15% and 0.5% of various minerals i.e., N, P, K, Ca, Mg and Cu respectively in various combinations were studied on larval development and silk production of Bombyx mori L. The rearing of silkworm larvae was restricted to chopped tender and green mulberry leaves treated with different concentrations. The results revealed that mineral nutrients have not affected the yield component significantly but have also presented better food consumption, body weight, co- efficient of utilization and larval development as well. However, of all the test treatments T11 where the offered mulberry leaves were treated with 0.2% N + 0.3% K + 0.1% Ca + 0.1% P + 0.15% Mg + 0.5% Cu concentration gave the best results

    Citation

    FULL TEXT

     

    posted Jul 16, 2010, 1:20 AM by rajesh gk

    Title

    Dimethyl sulphoxide inhibits in vitro synthesis of juvenile hormone I and II and stimulates juvenile hormone III by corpora allata of insects

    Authors

    B. G. Unni1,*, Ken E. Peck2, M. M. Pytel2, K. H. Dahm2, G. Bhaskaran2, H. Ranjit Singh1, Y. Kakoty1, B. Devi1 and S. B. Wann1

    1Biotechnology Division, North East Institute of Science and Technology (formerly Regional Research Laboratory), Jorhat 785 006, India 2Department of Biology, Texas A&M University, College Station, Texas 71843, USA

    Journal

    CURRENT SCIENCE, VOL. 96, NO. 8, 25 APRIL 2009

    Abstract

    Dimethyl sulphoxide (DMSO) specifically inhibits the rates of biosynthesis of juvenile hormone I (JH I) and juvenile hormone II (JH II) in corpora allata (CA) of 0 day last instar larvae of Manduca sexta maintained in vitro. Addition of mevalonate (Mev), propionate and homomevalonate (HMeV) to the medium increased the rate of biosynthesis of both JH II and JH III in normal CA. Even with added Mev, DMSO drastically reduced the rate of synthesis of both the higher homologues, but enhanced the rate of JH III synthesis even more with DMSO alone. The mated adult female CA which secretes JH II and JH III, and almost no JH I, also showed similar pattern of response to DMSO in larval CA. Allatotropin-stimulated JH II synthesis was also blocked by DMSO. DMSO inhibited JH II synthesis in Galleria mellonella, but the rate of JH III synthesis showed no increase. Likewise, in the CA ofadult male, Hyalophora cecropia which secretes only JH I and JH II acids, DMSO suppressed the synthesis of both acids, but there was no elevation in the rate of JH III acid synthesis. DMSO stimulated the rate of JH III synthesis, the only homologue secreted by the adult  female CA of cockroach, Blaberus discoidalis. Further in vivo studies showed that DMSO enhanced the growth of the silkworm larvae and silk fibre production.

     

    Title

    [Protein databank for several tissues derived from five instar of silkworm]

    [Article in Chinese]

    Authors

    Zhong BX.

    Department of Sericulture and Apiculture Science, College of Animal Sciences, Zhejiang University, Hangzhou 310029, China.

    Journal

    Yi Chuan Xue Bao. 2001;28(3):217-24.

    Abstract

    We attempted to construct protein databank of silkworm (Bombyx mori L.) for clarifying the gene expression and post-translational modification. Proteins from silkworm body wall, fat body and middle intestines were separated by two-dimensional electrophoresis. The N-terminal amino acid sequences of 40 proteins and their homology to proteins from other organisms were determined. 58.5% proteins were high homologous to the already reported proteins in D. melanogaster and 36.5% to those in other organisms. Only 5% of the proteins were homologous to the known protein in silkworm. The N-terminal sequences of 27 proteins were first found in silkworm, and all these data were registered in SWISS-PROT through the Internet. The results suggested that the information of gene expression and post-translational modification could be obtained by the information of protein databank.

    Citation

    http://www.ncbi.nlm.nih.gov/pubmed/11280994 PMID: 11280994 [PubMed - indexed for MEDLINE]

    posted Jul 9, 2010, 9:22 AM by rajesh gk

    Title

    [Fluoride accumulation and distribution in mulberry insects near fluoride pollution sources]

    [Article in Chinese]

    Authors

    Chen Y, Lu S.

    Department of Sericulture and Apiculture, Zhejiang University, Hangzhou 310029.

    Journal

    Ying Yong Sheng Tai Xue Bao. 2002 Jan;13(1):106-8.

    Abstract

    Fluoride accumulation and the relative fluoride loading of different body parts in wild mulberry silkworm (Bombyx mandarina M.), mulberry geometrid (Pathonandria atrineata B.), and mulberry silkworm (Bombyx mori L.) near fluoride pollution sources were studied. Comparison of the fluoride content of insect bodies and mulberry leaves showed that insects collected from polluted sites had increased fluoride accumulation. The digestive tract of the insect had much higher fluoride content than the other parts of the body and was considered to be the important organ of fluoride accumulation. There were also wide differences in fluoride accumulation between different insect species within the same polluted site. The highly significantly correlation between fluoride contents of wild mulberry silkworm, mulberry geometrid, and mulberry silkworm with that of the mulberry leaves on which they were collected was found.

    Citation

    http://www.ncbi.nlm.nih.gov/pubmed/11962305 PMID: 11962305 [PubMed - indexed for MEDLINE]

     

    Title

    Immune stimulation in the silkworm, Bombyx mori L., by CpG oligodeoxynucleotides.

    Authors

    Kim I, Kim SH, Lee YS, Yun EK, Lee HS, Kim JW, Ryu KS, Kang PD, Lee IH.

    Department of Sericulture & Entomology, National Institute of Agricultural Science and Technology, Rural Development Administration, Suwon, South Korea.

    Journal

    Arch Insect Biochem Physiol. 2004 Jan;55(1):43-8.

    Abstract

    Synthetic ODNs containing unmethylated CpG dinucleotides are known to stimulate immune responses in vertebrates, but so far the effect has not been studied in insects. In this report, we describe an induction of immune response following injection of oligodeoxynucleotides (ODNs) into the insect hemocoel. The fifth instar silkworm (Bombyx mori L.) larvae were injected with several synthetic ODNs containing variable number of unmethylated CpG motifs, heat-denatured genomic DNA of B. mori itself, or intact genomic DNA to observe a new induction pattern in the insect immune mechanism. When the induction of immune response was examined based on the expression rates of genes for antibacterial peptides such as attacin and cecropin, we could confirm that it was triggered upon injection of ODNs. The expression was, however, neither dependent on numbers of CpG motifs nor methylation of CpGs in ODNs. Furthermore, it was confirmed that the presence of CpG in ODN was not involved in the induction pattern of insect immunity caused by ODNs, although it has been reported that vertebrates respond in a specific manner against invading ODNs containing CpG dinucleotides. In addition, insect immunity was not stimulated by injection of intact DNA from host. In contrast, the injection of denatured genomic DNA provoked the host immune reaction. Taken together, our data suggest that foreignness of ODNs or DNA might be a key factor in the induction of insect immunity. Copyright 2003 Wiley-Liss, Inc.

    Citation

    http://www.ncbi.nlm.nih.gov/pubmed/14691962 PMID: 14691962 [PubMed - indexed for MEDLINE]

     

    Title

    Sinusoidal magnetic fields and chawki (silkworm) rearing in sericulture.

    Authors

    Qadri SM, Dhahira Beevi N, Mani A, Leelapriya T, Dhilip KS, Sanker Narayan PV.

    Regional Sericultural Research Station, CSB, Govt. of India, Salem, Tamil Nadu, India.

    Journal

    Electromagn Biol Med. 2006;25(3):145-53.

    Abstract

    Effects of sinusoidal magnetic fields on chawki silkworm rearing have been studied. The experiment was conducted using a multi X Bi silkworm hybrid, PM x CSR 2. Disease-free layings were reared from hatching to cocooning and by subjecting first and second instar to three magnetic field frequencies: 0.1, 1.0, and 10 Hz at 1500 nT, pp, for six days at six hours per day. Controls were maintained simultaneously. Larval durations for both young-stage chawki (I and II) and late stage (III, IV, V) were calculated in days and hours, including the feeding and moulting periods for I to IV instars, and the feeding period for V instar up to the time of spinning. The study revealed that the magnetic exposures reduced both feeding and moulting times with no adverse effects on larval growth. The substantial reductions in time, 33 hours in instars I and II, and 64 hours in total larval duration, could be commercially important in chawki rearing, saving time, leaf consumption, and labor expenses.

    Citation

    http://www.ncbi.nlm.nih.gov/pubmed/16954117 PMID: 16954117 [PubMed - indexed for MEDLINE]

     

    Title

    Apyrene sperm from the triploid donors restore fecundity of cryopreserved semen in Bombyx mori.

    Authors

    Takemura Y, Sahara K, Mochida Y, Ohnuma A.

    Institute of Sericulture, 1053 Iikura, Ami-machi, Ibaraki 300-0324, Japan.

    Journal

    J Insect Physiol. 2006 Oct;52(10):1021-6. Epub 2006 Jul 15.

    Abstract

    Female moths of Bombyx mori were artificially inseminated with cryopreserved semen. The fertility of inseminated females varied from 0% to 76.9% depending on the strain. Addition of fresh semen from triploid males, which are infertile but whose semen includes intact apyrene sperm, greatly improved fecundity of cryopreserved semen from normal males. Frozen apyrene sperm from the triploid donors also improved the fecundity of females, inseminated with cryopreserved normal semen, but less than fresh semen from triploid males. Fertilization success in B. mori requires the presence of both, intact eupyrene and apyrene sperm. Our results show that eupyrene sperm tolerate the cryopreservation process better than apyrene sperm. Hence, we recommend to add apyrene sperm from the triploid donors as helper sperm routinely to cryopreserved semen in artificial insemination. This may advance the application of cryopreservation as a routine technique to maintain silkworm resources. The technique may also be applicable to other moth and butterfly species which, like B. mori, possess eupyrene and apyrene sperm.

    Citation

    http://www.ncbi.nlm.nih.gov/pubmed/16963075 PMID: 16963075 [PubMed - indexed for MEDLINE]

     

    Title

    The UDP-glucosyltransferase multigene family in Bombyx mori. Free PMC Article

    Authors

    Huang FF, Chai CL, Zhang Z, Liu ZH, Dai FY, Lu C, Xiang ZH.

    The Key Sericultural Laboratory of Agricultural Ministry, Institute of Sericulture and Systems Biology, Southwest University, Chongqing 400715, PR China. huangfeifeisd@163.com

    Journal

    BMC Genomics. 2008 Nov 27;9:563.

    Abstract

    BACKGROUND: Glucosidation plays a major role in the inactivation and excretion of a great variety of both endogenous and exogenous compounds. A class of UDP-glycosyltransferases (UGTs) is involved in this process. Insect UGTs play important roles in several processes, including detoxication of substrates such as plant allelochemicals, cuticle formation, pigmentation, and olfaction. Identification and characterization of Bombyx mori UGT genes could provide valuable basic information for this important family and explain the detoxication mechanism and other processes in insects. RESULTS: Taking advantage of the newly assembled genome sequence, we performed a genome-wide analysis of the candidate UGT family in the silkworm, B. mori. Based on UGT signature and their similarity to UGT homologs from other organisms, we identified 42 putative silkworm UGT genes. Most of them are clustered on the silkworm chromosomes, with two major clusters on chromosomes 7 and 28, respectively. The phylogenetic analysis of these identified 42 UGT protein sequences revealed five major groups. A comparison of the silkworm UGTs with homologs from other sequenced insect genomes indicated that some UGTs are silkworm-specific genes. The expression patterns of these candidate genes were investigated with known expressed sequence tags (ESTs), microarray data, and RT-PCR method. In total, 36 genes were expressed in tissues examined and showed different patterns of expression profile, indicating that these UGT genes might have different functions. CONCLUSION: B. mori possesses a largest insect UGT gene family characterized to date, including 42 genes. Phylogenetic analysis, genomic organization and expression profiles provide an overview for the silkworm UGTs and facilitate their functional studies in future.

    Citation

    http://www.ncbi.nlm.nih.gov/pubmed/19038024 PMID: 19038024 [PubMed - indexed for MEDLINE]PMCID: PMC2633020

     

    Title

    Effects of hypervitaminosis of vitamin B3 on silkworm biology. Free Article

    Authors

    Etebari K, Matindoost L.

    Department of Sericulture, Faculty of Natural Resources, University of Guilan, Somehe Sara, Iran. etebari@guilan.ac.ir

    Journal

    J Biosci. 2004 Dec;29(4):417-22.

    Abstract

    A high-dose of vitamin B(3) in silkworm diet interrupts larval feeding and normal growth. High mortality of larvae occurs during molting and they cannot complete this process normally. Also the larvae exhibit nicotinamide hypervitaminosis symptoms such as immobility, dyspepsia, darkening of the skin, inability to excrete normally, exerting brownish fluid from anus and swelling of rectal muscles. Maximum larval weights in 1, 2 and 3 g/l treatments were 2.9, 1.6 and 1.2 g respectively, while maximum larval weight in the control was 5.6 g. Larval stage compared to control had increased 18, 26 and 31 days respectively. The concentration increase of uric acid in haemolymph demonstrates the hyperuricemia, while other measured biochemical compounds show significant decrease; sodium and potassium did not change significantly.

    Citation

    http://www.ncbi.nlm.nih.gov/pubmed/15625398 PMID: 15625398 [PubMed - indexed for MEDLINE]

     

    Title

    Membrane-penetrating trehalase from silkworm Bombyx mori. Molecular cloning and localization in larval midgut.

    Authors

    Mitsumasu K, Azuma M, Niimi T, Yamashita O, Yaginuma T.

    Sericulture and Entomoresources, Graduate School of Bioagricultural Sciences, Nagoya University, Chikusa, Nagoya, Japan.

    Journal

    Insect Mol Biol. 2005 Oct;14(5):501-8.

    Abstract

    The main blood sugar in insects, trehalose, differs from glucose in mammals. To incorporate trehalose into cells and utilize it, tissue cells possess the enzyme trehalase (EC3.2.1.28), which catalyses trehalose into glucose, in the organellar membrane or in the cytoplasm. Soluble and membrane-bound trehalase proteins have been isolated from insects. To date, however, only genes encoding the soluble trehalase have been reported in insects. Soluble trehalase is therefore believed to become localized on the cell surface via modification. In contrast, cDNAs encoding trehalase localized on the apical cell surface via the glycosylphosphatidylinositol-anchor have been isolated from mammalian small intestines. The amino acid sequence contains a specific hydrophobic region and an upstream omega site, which is cleaved for glycosylphosphatidylinositol-attachment, at the C-terminus. Here, we describe a cDNA from the silkworm Bombyx mori that encodes a novel trehalase (type-2) with one transmembrane domain and lacking the omega site. Immunoblotting and immunohistochemical analyses demonstrated that in the midgut tissue of Bombyx larvae, soluble trehalase-1 is present mainly in goblet cell cavities, but membrane-bound trehalase-2 is predominantly seen on the visceral muscle surrounding the midgut. To our knowledge, this is the first report of a cDNA encoding trehalase that penetrates the cell membrane in insects and its cellular localization.

    Citation

    http://www.ncbi.nlm.nih.gov/pubmed/16164606 PMID: 16164606 [PubMed - indexed for MEDLINE]

     

    Title

    Endoplasmic reticulum stress response of Bombyx mori calreticulin.

    Authors

    Goo TW, Park S, Jin BR, Yun EY, Kim I, Nho SK, Kang SW, Kwon OY.

    Department of Sericulture and Entomology, National Institute of Agricultural Science and Technology, Suwon, 441-744, Korea.

    Journal

    Mol Biol Rep. 2005 Sep;32(3):133-9.

    Abstract

    We isolated a calreticulin cDNA from the silkworm, Bombyx mori. The cDNA encodes 398 amino acid residues of B. mori calreticulin, with an endoplasmic reticulum retentional HDEL motif at its C-terminus and a predicted molecular mass of 45,801 Da. The B. mori calreticulin shows high protein homology with calreticulin from G. mellonella (88%), A. aegypti (71%), D. melanogaster (69%) and H. sapiens (63%). The highest level of mRNA expression of B. mori calreticulin was exhibited in the fat body of this insect. Although expression of B. mori calreticulin was affected by disturbances in intracellular calcium levels, other ER stress conditions such as inhibition of intracellular protein transport, reduction of disulfide formation, glycosylation inhibition, heat shock and oxidative stress did not disrupt induction of B. mori calreticulin.

    Citation

    http://www.ncbi.nlm.nih.gov/pubmed/16172913 PMID: 16172913 [PubMed - indexed for MEDLINE]

     

    Title

    Determination of iminosugars in mulberry leaves and silkworms using hydrophilic interaction chromatography-tandem mass spectrometry.

    Authors

    Nakagawa K, Ogawa K, Higuchi O, Kimura T, Miyazawa T, Hori M.

     

    Food and Biodynamic Chemistry Laboratory, Graduate School of Agricultural Science, Tohoku University, Sendai 981-8555, Japan.

    Journal

    Anal Biochem. 2010 May 12. [Epub ahead of print]

    Abstract

    Mulberry 1-deoxynojirimycin (DNJ, a potent alpha-glycosidase inhibitor) has been investigated thoroughly for its analytical methods and therapeutic potential against diabetes, whereas little attention has been given to other iminosugars such as 2-O-alpha-d-galactopyranosyl-DNJ (GAL-DNJ) and fagomine. For instance, concentration and composition of these iminosugars in mulberry leaves as well as sericulture products have not been fully characterized due to lack of suitable analytical methods. Here we developed a simultaneous determination method for DNJ, GAL-DNJ, and fagomine using hydrophilic interaction chromatography (HILIC) with tandem mass spectrometry (MS/MS). When mulberry leaf extracts were subjected to HILIC-MS/MS with multiple reaction monitoring (MRM), individual iminosugars could be separated and detected. The developed method is sufficiently sensitive for determining iminosugars in mulberry leaves as well as silkworms, providing new information (e.g., different amounts of iminosugars in mulberry leaf varieties; high DNJ and low GAL-DNJ in the silkworm body, especially in the blood) that is useful for producing iminosugar-rich products for nutraceutical purposes. Copyright © 2010 Elsevier Inc. All rights reserved.

    Citation

    http://www.ncbi.nlm.nih.gov/pubmed/20470744 PMID: 20470744 [PubMed - as supplied by publisher]

    posted Jul 5, 2010, 2:15 AM by rajesh gk

    Title

    Genome-wide identification and expression analysis of serine proteases and h omologs in the silkworm Bombyx mori. Free Article

    Authors

    Zhao P, Wang GH, Dong ZM, Duan J, Xu PZ, Cheng TC, Xiang ZH, Xia QY.

    Journal

    BMC Genomics. 2010 Jun 24;11(1):405. [Epub ahead of print]

    Abstract

    ABSTRACT: BACKGROUND: Serine proteases (SPs) and serine proteases homologs (SPHs) are a large group of proteolytic enzymes, with important roles in a variety of physiological processes, such as cell signalling, defense and development. Genome-wide identification and expression analysis of serine proteases and their homologs in the silkworm might provide valuable information about their biological functions. RESULTS: In this study, 51 SP genes and 92 SPH genes were systematically identified in the genome of the silkworm Bombyx mori. Phylogenetic analysis indicated that six gene families have been amplified species-specifically in the silkworm, and the members of them showed chromosomal distribution of tandem repeats. Microarray analysis suggests that many silkworm-specific genes, such as members of SP_fam12, 13, 14 and 15, show expression patterns that are specific to tissues or developmental stages. The roles of SPs and SPHs in resisting pathogens were investigated in silkworms when they were infected by Escherichia coli, Bacillus bombysepticus, Batrytis bassiana and B. mori nucleopolyhedrovirus, respectively. Microarray experiment and real-time quantitative RT-PCR showed that 18 SP or SPH genes were significantly up-regulated after pathogen induction, suggesting that SP and SPH genes might participate in pathogenic microorganism resistance in B. mori. CONCLUSION: Silkworm SP and SPH genes were identified. Comparative genomics showed that SP and SPH genes belong to a large family, whose members are generated mainly by tandem repeat evolution. We found that silkworm has species-specific SP and SPH genes. Phylogenetic and microarray analyses provide an overview of the silkworm SP and SPHs, and facilitate future functional studies on these enzymes.

    Citation

    PMID: 20576138 [PubMed - as supplied by publisher]

     

    Title

    Prothoracicotropic hormone induces tyrosine phosphorylation in prothoracic glands o f the silkworm, Bombyx mori.

    Authors

    Lin JL, Gu SH.

     

    Department of Zoology, National Museum of Natural Science, Taiwan, ROC.

    Journal

    Arch Insect Biochem Physiol. 2010 Jun 21. [Epub ahead of print]

    Abstract

    In the present study, we investigated the tyrosine phosphorylation of Bombyx mori prothoracic glands using phosphotyrosine-specific antibodies and Western blot analysis. Results showed that prothoracicotropic hormone (PTTH) stimulates a rapid increase in tyrosine phosphorylation of at least 2 proteins in prothoracic glands, one of which was identified as extracellular signal-regulated kinase (ERK). The phosphorylation of another 120-kDa protein showed dose- and time-dependent stimulation by PTTH in vitro. In vitro activation of tyrosine phosphorylation was also verified by in vivo experiments: injection of PTTH into day-6 last-instar larvae greatly increased tyrosine phosphorylation. Treatment of prothoracic glands with the protein tyrosine phosphatase inhibitor, sodium orthovanadate, also resulted in tyrosine phosphorylation of several proteins and increased ecdysteroidogenesis. The PTTH-stimulated phosphorylation of the 120-kDa protein was markedly attenuated by genistein, a broad-spectrum tyrosine kinase inhibitor, but not by HNMPA-(AM)(3), a specific inhibitor of insulin receptor tyrosine kinase. PP2, a more-selective inhibitor of the Src-family tyrosine kinases, partially inhibited PTTH-stimulated tyrosine phosphorylation, but not ecdysteroidogenesis. This result implies the possibility that in addition to ERK, the phosphorylation of the 120-kDa protein, which is not Src-family tyrosine kinase, is likely also involved in PTTH-stimulated ecdysteroidogenesis in B. mori. (c) 2010 Wiley Periodicals, Inc.

    Citation

    PMID: 20568296 [PubMed - as supplied by publisher]

     

    Title

    Transcriptional regulation of the gene for prothoracico tropic hormone in the silkworm, Bombyx mori.

    Authors

    Wei ZJ, Yu M, Tang SM, Yi YZ, Hong GY, Jiang ST.

     

    Department of Biotechnology, Hefei University of Technology, Hefei, 230009, People's Republic of China, zjwei@hfut.edu.cn.

    Journal

    Mol Biol Rep. 2010 Jun 19. [Epub ahead of print]

    Abstract

    Prothoracicotropic hormone (PTTH) is one of key players in regulation of insect growth, molting, metamorphosis, diapause, and is expressed specifically in the two pairs of lateral PTTH-producing neurosecretory cells in the brain. Analysis of cis-regulatory elements of the PTTH promoter might elucidate the regulatory mechanism controlling PTTH expression. In this study, the PTTH gene promoter of Bombyx mori (Bom-PTTH) was cloned and sequenced. The cis-regulatory elements in Bom-PTTH gene promoter were predicted using Matinspector software, including myocyte-specific enhancer factor 2, pre-B-cell leukemia homeobox 1, TATA box, etc. Transient transfection assays using a series of fragments linked to the luciferase reporter gene indicated that the fragment spanning -110 to +33 bp of the Bom-PTTH promoter showed high ability to support reporter gene expression, but the region of +34 to +192 bp and -512 to -111 bp repressed the promoter activity in the BmN and Bm5 cell lines. Electrophoretic mobility shift assays demonstrated that the nuclear protein could specifically bind to the region spanning -124 to -6 bp of the Bom-PTTH promoter. Furthermore, we observed that the nuclear protein could specifically bind to the -59 to -30 bp region of the Bom-PTTH promoter. A classical TATA box, TATATAA, localized at positions -47 to -41 bp, which is a potential site for interaction with TATA box binding protein (TBP). Mutation of this TATA box resulted in no distinct binding band. Taken together, TATA box was involved in regulation of PTTH gene expression in B. mori.

    Citation

    PMID: 20563654 [PubMed - as supplied by publisher]

     

    Title

    The density of females of Palmistichus elaeisis Delvare and LaSalle (Hymenoptera: Eulophidae) affects their reproductive performance on pupae of Bombyx mori L. (Lepidoptera: Bombycidae). Free Article

    Authors

    Pereira FF, Zanuncio JC, Serrão JE, Zanuncio TV, Pratissoli D, Pastori PL.

     

    Universidade Federal da Grande Dourados, MS, Brasil. fabriciofagundes@ufgd.edu.br <fabriciofagundes@ufgd.edu.br>

    Journal

    An Acad Bras Cienc. 2010 Jun;82(2):323-31.

    Abstract

    Palmistichus elaeisis Delvare and LaSalle (Hymenoptera: Eulophidae) is a gregarious and polyphagous parasitoid mainly of Lepidoptera pupae. The objective of this paper as to study the developent of parasitoid on Bombyx mori L. (Lepidoptera: Bombycidae) pupae exposed to one, nine, 18, 27, 36, 45 or 54 female P. elaeisis, respectively. The females of the parasitoid remained in contact with pupae for 24 hours in glass tubes (14.0 x 2.2 cm), packed in a climatic chamber regulated at 25 +/- 2 degrees C, 70 +/- 10% relative humidity and photo phase of 12 hours. With the exception of density 1:1 (72.72%), in other densities parasitism was 100%. Adults of P. elaeisis did not emerge from pupae at densities of 1:1 and 9:1, but 100.0% of parasitoid emergence was observed at the density of 45:1 and 54.54% at 54:1. The duration of the life cycle of this parasitoid ranged from 20 to 28 days. P. elaeisis produced 49 to 589 descendants per pupa of B. mori. The sex ratio of P. elaeisis ranged from 0.93 +/- 0.01 to 0.97 +/- 0.01 without differences with 18, 27, 36, 45 and 54 females/host. This parasitoid should be reared with the density of 45 females per pupa of B. mori.

    Citation

    PMID: 20563413 [PubMed - in process]

     

    Title

    Gqalpha-linked phospholipase Cbeta1 a nd phospholipase Cgamma are essential components of the pheromone biosynthesis activating neuropeptide (PBAN) signal transduction cascade.

    Authors

    Hull JJ, Lee JM, Matsumoto S.

     

    Molecular Entomology Laboratory, RIKEN Advanced Science Institute, Wako, Saitama, Japan.

    Journal

    Insect Mol Biol. 2010 Jun 10. [Epub ahead of print]

    Abstract

    Abstract Sex pheromone production for most moths is regulated by pheromone biosynthesis activating neuropeptide (PBAN). In Bombyx mori, PBAN binding triggers the opening of store-operated Ca(2+) channels, suggesting the involvement of a receptor-activated phospholipase C (PLC). In this study, we found that PLC inhibitors U73122 and compound 48/80 reduced sex pheromone production and that intracellular levels of (3)H-inositol phosphate species increased following PBAN stimulation. In addition, we amplified cDNAs from pheromone glands corresponding to PLCbeta1, PLCbeta4, PLCgamma and two G protein alpha subunits, Go and Gq. In vivo RNA interference-mediated knockdown analyses revealed that BmPLCbeta1, BmGq1, and unexpectedly, BmPLCgamma, are part of the PBAN signal transduction cascade.

    Citation

    PMID: 20546038 [PubMed - as supplied by publisher]

     

    Title

    Non-molting glossy/shroud encodes a short-chain dehydrogenase/reductase that fun ctions in the 'Black Box' of the ecdysteroid biosynthesis pathway.

    Authors

    Niwa R, Namiki T, Ito K, Shimada-Niwa Y, Kiuchi M, Kawaoka S, Kayukawa T, Banno Y, Fujimoto Y, Shigenobu S, Kobayashi S, Shimada T, Katsuma S, Shinoda T.

     

    Graduate School of Life and Environmental Sciences, University of Tsukuba, Tennoudai 1-1-1, Tsukuba, Ibaraki 305-8572, Japan. ryusuke-niwa@umin.ac.jp

    Journal

    Development. 2010 Jun;137(12):1991-9.

    Abstract

    In insects, the precise timing of molting and metamorphosis is strictly guided by a principal steroid hormone, ecdysone. Among the multiple conversion steps for synthesizing ecdysone from dietary cholesterol, the conversion of 7-dehydrocholesterol to 5beta-ketodiol, the so-called 'Black Box', is thought to be the important rate-limiting step. Although a number of genes essential for ecdysone synthesis have recently been revealed, much less is known about the genes that are crucial for functioning in the Black Box. Here we report on a novel ecdysteroidgenic gene, non-molting glossy (nm-g)/shroud (sro), which encodes a short-chain dehydrogenase/reductase. This gene was first isolated by positional cloning of the nm-g mutant of the silkworm Bombyx mori, which exhibits a low ecdysteroid titer and consequently causes a larval arrest phenotype. In the fruit fly, Drosophila melanogaster, the closest gene to nm-g is encoded by the sro locus, one of the Halloween mutant members that are characterized by embryonic ecdysone deficiency. The lethality of the sro mutant is rescued by the overexpression of either sro or nm-g genes, indicating that these two genes are orthologous. Both the nm-g and the sro genes are predominantly expressed in tissues producing ecdysone, such as the prothoracic glands and the ovaries. Furthermore, the phenotypes caused by the loss of function of these genes are restored by the application of ecdysteroids and their precursor 5beta-ketodiol, but not by cholesterol or 7-dehydrocholesterol. Altogether, we conclude that the Nm-g/Sro family protein is an essential enzyme for ecdysteroidogenesis working in the Black Box.

    Citation

    PMID: 20501590 [PubMed - indexed for MEDLINE]

     

    Title

    Isolation of a bioactive substance from the silkworm (Bombyx mor i Linnaeus) that accelerates the germination of the entomopathogenic fungus Nomuraea rileyi (Farlow) Samson. Free Article

    Authors

    Noda T, Ono M, Iimure K, Araki T.

     

    Kumamoto Prefectural Agriculture Research Center, Koshi, Kumamoto, Japan. noda-t-dw@pref.kumamoto.lg.jp

    Journal

    Biosci Biotechnol Biochem. 2010 Mar 23;74(3):563-8. Epub 2010 Mar 7.

    Abstract

    The conidium of the entomopathogenic fungus Nomuraea rileyi has been found to germinate rapidly in the presence of host insect-derived extracts. Thus the extract appears to contain an important factor involved in host recognition by N. rileyi. However, the substance responsible for such unique germination behavior has yet to be identified. Hence we attempted to purify this substance. One thousand g of dried silkworm pupae was subjected to methanol extraction, followed by methanolysis, two different solvent partitions, and three different column chromatographies. A total of 12.4 mg of substance was obtained in the active fraction. The substance obtained exhibited an activity more than 46,000 times higher than that of the methanol extract. The substance was detected as a single peak on Sephadex LH20 column chromatography and as a single band on high-performance thin-layer chromatography. These data indicate that the concentrated fraction contained a high-purity substance.

    Citation

    PMID: 20208348 [PubMed - indexed for MEDLINE]

     

    Title

    A palmitoyl conjugate of insect pentapeptide Yamamarin arrests cell proliferation a nd respiration.

    Authors

    Sato Y, Yang P, An Y, Matsukawa K, Ito K, Imanishi S, Matsuda H, Uchiyama Y, Imai K, Ito S, Ishida Y, Suzuki K.

     

    Department of Agro-Bioscience, Faculty of Agriculture, Iwate University, Morioka 020-8550, Japan.

    Journal

    Peptides. 2010 May;31(5):827-33. Epub 2010 Mar 3.

    Abstract

    A palmitoyl conjugate of an insect pentapeptide that occurs in diapausing insects causes a reversible cell-cycle arrest and suppresses mitochondrial respiration. This peptide compound also causes growth arrest in murine leukemic cell line expressing human gene Bcr/Abl and a farnesoyl peptide induces embryonic diapause in Bombyx mori. These results demonstrate that the insect peptide compounds can lead to the understanding of a common pathway in developmental arrest in animals and may provide a new peptidominetic analog in the development of biopharmaceuticals and pest management. Copyright (c) 2010 Elsevier Inc. All rights reserved.

    Citation

    PMID: 20206219 [PubMed - indexed for MEDLINE]

     

    Title

    Apolipophorin-III expression and low density lipop horin formation during embryonic development of the silkworm, Bombyx mori.

    Authors

    Tsuchida K, Yokoyama T, Sakudoh T, Katagiri C, Tsurumaru S, Takada N, Fujimoto H, Ziegler R, Iwano H, Hamano K, Yaginuma T.

     

    National Institute of Infectious Diseases, Tokyo, Japan. kozo@nih.go.jp

    Journal

    Comp Biochem Physiol B Biochem Mol Biol. 2010 Apr;155(4):363-70. Epub 2010 Jan 14.

    Abstract

    We examined the expression of apolipophorin-III (apoLp-III) during embryonic development of the silkworm Bombyx mori. ApoLp-III mRNA was first expressed 24h after oviposition, which corresponds to the time of germ band formation. The amount of apoLp-III in the eggs increased from day 2, peaked on day 4, and then gradually decreased until hatching (on day 9.5). ApoLp-III was apparently synthesized during early embryogenesis, as radioactive amino acids were incorporated into newly synthesized apoLp-III in three-day-old eggs. Moreover, radioactive apoLp-III was found only in the embryo and not in the extraembryonic tissue. KBr density gradient ultracentrifugation of egg homogenates showed that apoLp-III was associated with low-density lipophorin (LDLp). These results suggest that LDLp is required for the delivery of lipids for organogenesis during embryogenesis. 2010 Elsevier Inc. All rights reserved.

    Citation

    PMID: 20079870 [PubMed - indexed for MEDLINE]

     

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