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

Title

Cloning of two Bombyx homologues of the Drosophila rosy gene and their relationship to larval translucent skin colour mutants.

Authors

Yasukochi Y, Kanda T, Tamura T.

National Institute of Sericulture and Entomological Science (NISES), Ibaraki, Japan. Yaskoch@nises.affrc.go.jp

Journal

Genet Res. 1998 Feb;71(1):11-9.

Abstract

To clone the Bombyx xanthine dehydrogenase (XDH) gene as a dominant marker for silkworm transgenesis, we performed nested reverse transcriptase-polymerase chain reaction (RT-PCR) using embryonic mRNA and primers designed from the conserved region of Drosophila and rat XDH genes. Sequencing of amplified 180 bp fragments showed that two different sequences were present in the fragments. Since both possessed striking similarity to XDH genes of other organisms, we considered these to be portions of silkworm XDH genes and designated them BmXDH1 and BmXDH2. Subsequently we cloned separately the entire region of the two cDNAs by PCR using phage DNA of an embryonic cDNA library and sequenced them. The two cDNAs were around 4 kb in size and possessed complete open reading frames. The deduced amino acid sequences of the two BmXDHs were very similar to each other and to those of other organisms. The expression pattern of wild-type larvae basically followed the tissue specificity of the enzyme and no significant difference was observed between the two XDH genes. The expression of both genes was detected in the XDH-deficient mutants, oq and og, but non-synonymous substitutions were specifically detected in the BmXDH1 of the oq mutant. In addition, a length polymorphism of the second intron of the BmXDH1 co-segregated with the oq translucent phenotype, suggesting that deficiency in BmXDH1 is the cause of the oq translucent phenotype.

Citation

http://www.ncbi.nlm.nih.gov/pubmed/9674379 PMID: 9674379 [PubMed - indexed for MEDLINE]

 

Title

Structure of the Bombyx sorbitol dehydrogenase gene: a possible alternative use of the promoter.

Authors

Niimi T, Yamashita O, Yaginuma T.

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

Journal

Insect Mol Biol. 1996 Nov;5(4):269-80.

Abstract

In an initial effort to understand the molecular mechanism of how low temperature induces sorbitol dehydrogenase gene expression in diapause eggs of the silkworm, the sorbitol dehydrogenase gene was isolated from a Bombyx genomic library using a cDNA encoding the Bombyx homologue of mammalian sorbitol dehydrogenase as a probe. The gene extended for about 10 kb, consisting of eight exons and seven introns. Four TATA motifs were found in the 5' upstream region of the gene, without CCAAT. AATTAA, instead of AATAAA, was localized in the upstream region of the polyadenylation site. Although a single copy of this gene was present per haploid genome, 1.2 kb and 1.1 kb transcripts were found from yolk cells in diapause eggs and from larval fat-body cells, respectively. The two major transcription initiation sites corresponding to both transcripts were localized at 355 and 226 base pairs upstream from the transition start site, indicating an alternative use of promoter. The 5'-upstream region of the gene contained a consensus sequence, TGA(A/T)AA(A/G/T), that has been found in insect genes expressed mainly in larval and pupal fat bodies. It also contained three kinds of sequences similar to cis-elements recognized by members of the steroid receptor superfamily, such as chicken ovalbumin upstream promoter transcription factor (COUP-TF)/Drosophila Seven up (SVP), Drosophila hormone receptor 39 (DHR39) and Bombyx fushi tarazu transcriptional factor 1 (BmFTZ-F1).

Citation

http://www.ncbi.nlm.nih.gov/pubmed/8933178 PMID: 8933178 [PubMed - indexed for MEDLINE]

 

Title

Cloning of cDNAs encoding Bombyx homologues of Cdc2 and Cdc2-related kinase from eggs.

Authors

Iwasaki H, Takahashi M, Niimi T, Yamashita O, Yaginuma T.

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

Journal

Insect Mol Biol. 1997 May;6(2):131-41.

Abstract

In diapausing eggs of the silkworm Bombyx mori, embryonic cells are arrested at G2 phase. The ability to undertake cell division is resumed in the course of diapause termination caused by such a treatment as acclimation to 5 degrees C. As an initial trial to investigate the relationship between diapause and embryonic cell cycling, we have cloned and sequenced two Bombyx cDNAs encoding two distinct cdc2-related Ser/Thr protein kinases. One (Bm cdc2) encoded a 37.0 kDa protein which had all of the domains characteristic of other Cdc2 kinase. The other (Bcdrk) encoded a 45.1 kDa protein that was most similar to Drosophila and human cdc2-related protein kinases (Dcdrk protein and PISSRLE kinase). Northern blot analysis was carried out to examine levels of Bm cdc2 and Bcdrk mRNA during embryogenesis of non-diapause eggs. The result demonstrated that the mRNA level of Bm cdc2 appeared to correspond to the activity of nuclear/cellular division in non-diapause eggs, and that the developmental profile in the level of Bcdrk mRNA was somewhat different from that of Bm cdc2 mRNA.

Citation

http://www.ncbi.nlm.nih.gov/pubmed/9099577 PMID: 9099577 [PubMed - indexed for MEDLINE]

 

Title

Dominant lethals induced by Dithane M-45 in silkworm Bombyx mori.

Authors

Vasudev V, Subramanya G, Krishnamurthy NB.

Department of Studies in Zoology, University of Mysore, India.

Journal

Environ Res. 1994 Apr;65(1):145-8.

Abstract

Dithane M-45, a ethylenebis(dithiocarbamate) fungicide widely used in agriculture, including moriculture and sericulture, was tested for its efficacy in inducing dominant lethals in Bombyx mori. A polyvotine race of Pure Mysore was used for the studies and the topical application method was employed. After treatment with sublethal concentrations of 5, 10, and 20 g/50 larvae, the results have revealed that all of the concentrations could induce significant dominant lethals in a dose-dependent manner compared to controls. The results are discussed in the light of precautionary measures in the use of Dithane M-45 in the sericulture industry.

Citation

http://www.ncbi.nlm.nih.gov/pubmed/8162881 PMID: 8162881 [PubMed - indexed for MEDLINE]

 

Title

Identification and expression analysis of ras gene in silkworm, Bombyx mori.

Authors

Ogura T, Tan A, Tsubota T, Nakakura T, Shiotsuki T.

Department of Applied Life Sciences, Kyoto University, Kyoto, Japan.

Journal

PLoS One. 2009 Nov 25;4(11):e8030.

Abstract

Ras proteins play important roles in development especially for cell proliferation and differentiation in various organisms. However, their functions in the most insect species are still not clear. We identified three ras cDNAs from the silk worm, Bombyx mori. These sequences corresponded to three Ras of Drosophila melanogaster, but not to three mammalian Ras (H-Ras, K-Ras, N-Ras). Subsequently, the expression profiles of ras were investigated by quantitative real-time PCR using whole body of individuals from the embryonic to adult stages, and various tissues of 4th and 5th instar larvae. Each of three Bombyx ras showed different expression patterns. We also showed membrane localization of their products. These results indicate that the three Bombyx Ras are functional and have different roles.

Citation

PMID: 19946625 [PubMed - indexed for MEDLINE]PMCID: PMC2777509 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

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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

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Title

Investigation on Intera-Specific Biodiversity of 51 Peanut Cocoon Strains of Iran Silkworm (Bombyx mori) Germplasm Based on Reproductive Traits

Authors

M. Mavvajpour ; A.R. Seidavi ; S. Gharahveysi ; M. Salehi Nezhad ; S.Z. Mirhosseini

Journal

Biotechnology

Abstract

This study was conducted in ordered to analyze of phylogenetic relationships and determination of relationship amounts in all peanut cocoon strains of Islamic Republic of Iran germplasm based on reproductive characteristics. Hierarchical agglomerative clustering was done by using NTSYS-pc, version 2.02e based on complete, single, UPGMA, UPGMC, FLEXI approaches and SAS-pc based on WARD and average approaches. However, method of average linkage between groups under UPGMA (Unweighted Pair-Group Method using Arithmetic average) was considered as major and final protocol for data conclusion and the resulting clusters were expressed as dendrograms. Various methods generated similar dendograms. This study reveals the phylogenetic relationship of peanut cocoon strains of Iran germplasm. Based on data from studied characters, we constructed dendrograms that resolved the 51 silkworm strains into 2 major clusters. However, the strains of the same origin did not grouped together, demonstrating they can have different biological and development performance. First cluster divided into one sub-group included five strains. However, second cluster divided into two sub-groups. Other strains were grouped together and far from other silkworm strains, indicating they might be suitable for future crossings, maintenance of parental strains and hybridizations with oval cocoon strains so as to maximize heterosis and to avoid depression inbreeding.

Citation

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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

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Title

Genetic diversity, molecular phylogeny and selection evidence of the silkworm mitochondria implicated by complete resequencing of 41 genomes

Authors

Li Dong ; Guo Yiran ; Shao Haojing ; Tellier Laurent ; Wang Jun ; Xiang Zhonghuai ; Xia Qingyou

Journal

BMC Evolutionary Biology, 2010

Abstract

Background: Mitochondria are a valuable resource for studying the evolutionary process and deducing phylogeny. A few mitochondria genomes have been sequenced, but a comprehensive picture of the domestication event for silkworm mitochondria remains to be established. In this study, we integrate the extant data, and perform a whole genome resequencing of Japanese wild silkworm to obtain breakthrough results in silkworm mitochondrial (mt) population, and finally use these to deduce a more comprehensive phylogeny of the Bombycidae.

Results: We identified 347 single nucleotide polymorphisms (SNPs) in the mt genome, but found no past recombination event to have occurred in the silkworm progenitor. A phylogeny inferred from these whole genome SNPs resulted in a well-classified tree, confirming that the domesticated silkworm, Bombyx mori, most recently diverged from the Chinese wild silkworm, rather than from the Japanese wild silkworm. We showed that the population sizes of the domesticated and Chinese wild silkworms both experience neither expansion nor contraction. We also discovered that one mt gene, named cytochrome b, shows a strong signal of positive selection in the domesticated clade. This gene is related to energy metabolism, and may have played an important role during silkworm domestication.

Conclusions: We present a comparative analysis on 41 mt genomes of B. mori and B. mandarina from China and Japan. With these, we obtain a much clearer picture of the evolution history of the silkworm. The data and analyses presented here aid our understanding of the silkworm in general, and provide a crucial insight into silkworm phylogeny.

Citation

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Title

The QTLs, Determination of Cocoon Shell Weight Trait in Mulberry Silkworm (Bombyx mori L.)

Authors

M. Taeb ; B. Rabiee ; S.Z. Mirhosseini ; A.R. Bizhannia

Journal

Biotechnology, 2010; 9 (1); p. 41-47

Abstract

The silkworm is an important economical insect in sericultural field. Its major production-economic characteristics are polygenic. In this study, three F2 populations (second generation) derived from three cross between three pairs, parents of Lemon Khorasan (as maternal) and 107 (as paternal) lines. we contacted AFLP (amplified fragment length polymorphism) technique for mapping genetic factors or QTLs that effect on Cocoon Shell Weight (CSW) trait. Following it we used 20 selected primer combinations of PstI/TaqI and DNAs were individually extracted to phenol-chloroform method. They digested by two restriction enzymes (TaqI and PstI) and also produced DNA fragments amplified by appropriate adaptors separately. After transferring of DNAs samples on annealed 6% polyacrylamide gels and genotyping of individuals, the linkage maps of each population were drawed. The QTLs for cocoon shell weight trait in LRS = LRT>12.5 (LOD>2.71) threshold level based on permutation test (n = 1000) and using compound interval mapping methods were analyzed and detected 5, 1 and 1 QTLs that were localized on linkage groups 9, 11; 12 and 24 in each studied F2 populations, respectively. The QTLs had different gene effects from over dominance, dominance to partial dominance.

Citation

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Title

Molecular genetic relationships between Bombycidae and Saturniidae based on the mitochondria DNA encoding of large and small rRNA.

Authors

Hwang JS, Lee JS, Goo TW, Yun EY, Sohn HR, Kim HR, Kwon OY.

National Sericulture and Entomology Research, R.D.A., Suwon, South Korea.

Journal

Genet Anal. 1999 Dec 15;15(6):223-8.

Abstract

The phylogenetic relationships between Bombycidae (Bombyx mori and Bombyx mandarina) and Saturniidae (Antheraea yamamai and Antheraea pernyi) were investigated based on large and small mitochondiral rRNA genes. About 430 bp of four kinds of PCR-amplified fragments were sequenced and aligned. For the 16S rRNA gene, B. mori shared a 98, 87 and 86% sequence homology with B. mandarina, A. yamamai and A. pernyi, and for the 12S rRNA gene, B. mori shared a 99, 89 and 88% sequence homology with B. mandarina, A. yamamai and A. pernyi, respectively. DNA sequence data were also used for a phylogenetic analysis. All of the trees showed monophyly for both Bombycidae and Saturniidae. The monophyly confidence limits of these trees were estimated using bootstrapping tests and measured more than 99% for all trees for both Bombycidae and Saturniidae.

Citation

http://www.ncbi.nlm.nih.gov/pubmed/10609758 PMID: 10609758 [PubMed - indexed for MEDLINE]

 

Title

Tissue-/stage-dependent expression of a cloned Bombyx mandarina QM homologue.

Authors

Hwang JS, Goo TW, Yun EY, Lee JH, Kang SW, Kim KY, Kwon OY.

National Sericulture and Entomology Research Institute, Rural Development Administration, Suwon, South Korea.

Journal

Biomol Eng. 2000 Jun;16(6):211-5.

Abstract

QM, a novel gene that was firstly isolated as a putative tumor suppressor gene from Wilms' tumor cell line. Although it is well known that the QM gene product plays an important role within the tumor cells, the precise role of QM in the non-tumor cells has remained elusive. With in this mind we isolated a cDNA encoding QM homologue from Bombyx mandarina to understand the function of QM. The 596 bp cDNA has an open reading frame of 219 amino acids and a predicted mol. wt. of 25 kDa. The protein has more than 88% amino acid sequence identity to the QM protein from Drosophila melanogaster. mRNA expression gradually increased from 1-2 days after egg laying to 2 days of finial instar, while very low expressions were detected for either the pupae and the moth stages. The organs, posterior/middle division of silkgland, midgut, fat body and malpighian tubes, also show relatively high mRNA expression levels, respectively. The high degree of conservation and expression of the B. mandarina QM homologous suggest that it has a selectively conserved amino acid sequence due, presumably, to an important biological role which is associated with pupae formation.

Citation

http://www.ncbi.nlm.nih.gov/pubmed/10894116 PMID: 10894116 [PubMed - indexed for MEDLINE]

 

Title

Tissue-/stage-dependent expression of a cloned Bombyx mandarina QM homologue.

Authors

Hwang JS, Goo TW, Yun EY, Lee JH, Kang SW, Kim KY, Kwon OY.

National Sericulture and Entomology Research Institute, Rural Development Administration, Suwon, South Korea.

Journal

Biomol Eng. 2000 Jun;16(6):211-5.

Abstract

QM, a novel gene that was firstly isolated as a putative tumor suppressor gene from Wilms' tumor cell line. Although it is well known that the QM gene product plays an important role within the tumor cells, the precise role of QM in the non-tumor cells has remained elusive. With in this mind we isolated a cDNA encoding QM homologue from Bombyx mandarina to understand the function of QM. The 596 bp cDNA has an open reading frame of 219 amino acids and a predicted mol. wt. of 25 kDa. The protein has more than 88% amino acid sequence identity to the QM protein from Drosophila melanogaster. mRNA expression gradually increased from 1-2 days after egg laying to 2 days of finial instar, while very low expressions were detected for either the pupae and the moth stages. The organs, posterior/middle division of silkgland, midgut, fat body and malpighian tubes, also show relatively high mRNA expression levels, respectively. The high degree of conservation and expression of the B. mandarina QM homologous suggest that it has a selectively conserved amino acid sequence due, presumably, to an important biological role which is associated with pupae formation.

Citation

http://www.ncbi.nlm.nih.gov/pubmed/10894116 PMID: 10894116 [PubMed - indexed for MEDLINE]

 

Title

Samui, a novel cold-inducible gene, encoding a protein with a BAG domain similar to silencer of death domains (SODD/BAG-4), isolated from Bombyx diapause eggs. Free Article

Authors

Moribe Y, Niimi T, Yamashita O, Yaginuma T.

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

Journal

Eur J Biochem. 2001 Jun;268(12):3432-42.

Abstract

Cellular responses to cold-acclimation have not yet been studied in depth. To explore this field, we focussed on insect diapause development. Although embryonic diapause of Bombyx mori is sustained at 25 degrees C, chilling at 5 degrees C for 2 months causes diapause termination, a transition that is marked when the sorbitol dehydrogenase gene (SDH) is activated. To clarify the relationship between this activation and incubation at 5 degrees C, we isolated a novel cold-inducible gene, Samui. Expression of Samui mRNA and protein was activated after incubation at 5 degrees C for 5-6 days, lasted for another 30 days and then weakened. Exposure to 25 degrees C suppressed both mRNA and protein expression. In nondiapause eggs incubated at 5 degrees C, Samui was also up-regulated, although the expression was weaker. Samui contained nuclear localization-signals, a ssDNA-binding motif and a BAG domain similar to that of SODD/BAG-4. Because Samui could bind to HSP70, it is a member of BAG protein family. It is proposed that Samui serves to transmit the '5 degrees C signal' for SDH expression in diapause eggs, while also protecting against cold-injures in nondiapause eggs, through binding to respective partners. This is the first report that a member of BAG protein family is up-regulated by cold.

Citation

http://www.ncbi.nlm.nih.gov/pubmed/11422373 PMID: 11422373 [PubMed - indexed for MEDLINE]

 

posted Jul 9, 2010, 9:18 AM by rajesh gk

Title

The genetics and genomics of the silkworm, Bombyx mori.

Authors

Goldsmith MR, Shimada T, Abe H.

Biological Sciences Department, University of Rhode Island, Kingston, Rhode Island 02881, USA. mki101@uri.edu

Journal

Annu Rev Entomol. 2005;50:71-100.

Abstract

We review progress in applying molecular genetic and genomic technologies to studies in the domesticated silkworm, Bombyx mori, highlighting its use as a model for Lepidoptera, and in sericulture and biotechnology. Dense molecular linkage maps are being integrated with classical linkage maps for positional cloning and marker-assisted selection. Classical mutations have been identified by a candidate gene approach. Cytogenetic and sequence analyses show that the W chromosome is composed largely of nested full-length long terminal repeat retrotransposons. Z-chromosome-linked sequences show a lack of dosage compensation. The downstream sex differentiation mechanism has been studied via the silkworm homolog of doublesex. Expressed sequence tagged databases have been used to discover Lepidoptera-specific genes, provide evidence for horizontal gene transfer, and construct microarrays. Physical maps using large-fragment bacterial artificial chromosome libraries have been constructed, and whole-genome shotgun sequencing is underway. Germline transformation and transient expression systems are well established and available for functional studies, high-level protein expression, and gene silencing via RNA interference.

Citation

http://www.ncbi.nlm.nih.gov/pubmed/15355234 PMID: 15355234 [PubMed - indexed for MEDLINE]

 

Title

Genetic characterization of Iranian native Bombyx mori strains using amplified fragment length polymorphism markers.

Authors

Mirhoseini SZ, Dalirsefat SB, Pourkheirandish M.

Department of Sericulture, Faculty of Natural Resources, University of Guilan, Somehe sara 1144, Iran.

Journal

J Econ Entomol. 2007 Jun;100(3):939-45.

Abstract

Genetic relationships within and among seven Iranian native silkworm strains was determined by DNA fingerprinting by using amplified fragment length polymorphism (AFLP) markers. In total, 189 informative AFLP markers were generated and analyzed. Estimates of Nei's gene diversity for all loci in individual strains showed a higher degree of genetic similarity within each studied strain. The highest and the least degrees of gene diversity were related to Khorasan Pink (h = 0.1804) and Baghdadi (h = 0.1412) strains, respectively. The unweighted pair-group method with arithmetic average dendrogram revealed seven strains of silkworm, Bombyx mori (L.), resolving into two major clusters. The highest degree of genetic similarity was related to Baghdadi and Harati White, and the least degree was related to Guilan Orange and Harati Yellow. The genetic similarity estimated within and among silkworms could be explained by the pedigrees, historical and geographical distribution of the strains, effective population size, inbreeding rate, selection intensity, and gene flow. This study revealed that the variability of DNA fingerprints within and among silkworm strains could provide an essential basis for breeders in planning crossbreeding strategies to produce potentially hetrotic hybrids in addition to contributing in conservation programs.

Citation

http://www.ncbi.nlm.nih.gov/pubmed/17598559 PMID: 17598559 [PubMed - indexed for MEDLINE]

 

Title

A genomewide survey of homeobox genes and identification of novel structure of the Hox cluster in the silkworm, Bombyx mori.

Authors

Chai CL, Zhang Z, Huang FF, Wang XY, Yu QY, Liu BB, Tian T, Xia QY, Lu C, Xiang ZH.

The Key Sericultural Laboratory of Agricultural Ministry, College of Biotechnology, Institute of Sericulture and Systems Biology, Southwest University, Chongqing, China

Journal

Insect Biochem Mol Biol. 2008 Dec;38(12):1111-20.

Abstract

Homeobox genes encode transcriptional factors that play crucial roles in a variety of developmental pathways from unicellular to multicellular eukaryotes. We have identified 102 homeobox genes in the typical insect of Lepidoptera, Bombyx mori, based on the newly assembled genome sequence with 9X coverage. These identified homeobox genes were categorized into nine classes including at least 74 families. The available ESTs and microarray data at present confirmed that more than half of them were expressed during silkworm developmental processes. Orthologs of pb, zen and ftz were newly identified in the Bombyx Hox cluster on chromosome 6. Interestingly, a special group of 12 tandemly duplicated homeobox genes was found located between Bmpb and Bmzen in the Bombyx Hox cluster, suggesting that Hox cluster might have experienced a lineage-specific expansion in the silkworm. A detailed analysis on genome data reveals that a split exists between Bmlab and Bmpb. Our data provide valuable information for future research on the development and evolution of silkworm.

Citation

http://www.ncbi.nlm.nih.gov/pubmed/19280701 PMID: 19280701 [PubMed - indexed for MEDLINE]

 

Title

[Three Bombyx mori genes, chi, gluE and fruA, encode proteins homologous to microorganism and primary analysis of horizontal gene transfer]

[Article in Chinese]

Authors

Cheng TC, Xia QY, Liu C, Zhao P, Zha XF, Xu HF, Xiang ZH.

Key Laboratory of Sericulture of the Agricultural Ministry of China, Southwest Agricultural University, Chongqing 400716, China. chengtc@swau.cq.cn

Journal

Yi Chuan Xue Bao. 2004 Oct;31(10):1082-8.

Abstract

According to the analysis of large scale EST sequencing of silkworm, Bombyx mori, we found that chi, glue and fruA of silkworm have very high homology at amino acid level and closely phylogenetic relative with that of microorganism, but lower similarity with genes of eelworm (Caenorhabditis elegans), fruitfly (Drosophila melanogaster), mosquito (Anopheles gambiae) and other relative insects, respectively. It indicates that each of them is likely to have common ancestor with that of microorganism. Namely, microbial genes were likely transferred to silkworm by horizontal gene transfer, instead of the vertical inheritance in evolutionary manner.

Citation

http://www.ncbi.nlm.nih.gov/pubmed/15552042 PMID: 15552042 [PubMed - indexed for MEDLINE]

 

Title

[Sex control of silkworm by the interaction between gene and environment]

[Article in Chinese]

Authors

Lin JR, Liao FP, Yan HC.

Department of Sericulture and Fashion Design, South China Agricultural University, Guangzhou, 510642, China. jrlin@scauedu.cn

Journal

Yi Chuan. 2002 Jan;24(1):27-30.

Abstract

The silkworm embryo of the varieties, sBan, K05, Ban1, S1 and D05 was sensitive to the high temperature and low humidity incubating condition, while that of Nong4, Xinjiu and Xiankang was more endurable. By crossing the female Xinjiu with the male of sensitive varieties, such as sBaa, K05, Ban1, S1 or D05, their female progenies were sensitive to the high temperature and low humidity during incubation and could not hatch, while the males could hatch normally. Experiment showed that silkworm sex could be controlled by the interaction between gene and environment. The sensitive period was at late stage during the embryo development. The RAPD analysis showed that the similarity index of the five temperature-sensitive varieties of sBan, K05, Ban1, S1 and D05 was 63.04-76.47%.

Citation

http://www.ncbi.nlm.nih.gov/pubmed/15901558 PMID: 15901558 [PubMed]

 

Title

[Pridiction of the Sex-effects of the Cocoon Quality Characters in Silkworm.]

[Article in Chinese]

Authors

Sima YH, Xu HM, Chen DX, Zhao AC, Li B, Lu C, Xiang ZH.

The Key Sericultural Laboratory of the Agricultural Ministry; College of Sericulture and Silk, Southwest Agricultural University, Chongqing 400716, China.

Journal

Yi Chuan. 2005 May;27(3):372-6.

Abstract

In this paper , the sex-effects of the cocoon quality characters in silkworm was predicted with Mixed linear model úThe fact that the probability of effect variance and predictability of random gender of whole cocoon weight, cocoon shell weight, ratio of cocoon shell and pupa weight reached a level of extreme significance showed that the gender effect of the four traits was extremely significant, which matched with the reality completely. The predictive values of gender effect of the four traits of female(male) were 0.248g (-0.247g), 2.423cg(-2.394)cg, -1.976%(1.992%) and 0.224g(-0.223g) respectively. Each trait showed single peak distribution after adjusting by sex-effects, which fitted for the request that quantitative traits should show continuously normal standard distribution if QTL analysis was taken.

Citation

http://www.ncbi.nlm.nih.gov/pubmed/15985399 PMID: 15985399 [PubMed - in process]

 

Title

DNA fingerprinting using AFLP markers to search for markers associated with yield attributes in the silkworm, Bombyx mori.

Authors

Gaviria DA, Aguilar E, Serrano HJ, Alegria AH.

 

Center for Molecular Biology and Biotechnology, Universidad Tecnológica de Pereira, Risaralda, Colombia. duberney82@netscape.net

Journal

J Insect Sci. 2006;6:1-10.

Abstract

This study was carried out on 11 Chinese and 12 Japanese silkworm strains maintained by the Center for the Technological Development of Sericulture (CDTS) germplasm bank, located in Pereira, Colombia. The goals were to determine the genetic population structure of the two groups and the association between molecular markers (AFLPs) and important productivity characters. Group analysis showed the separation of the strains according to their geographic origin. The molecular markers and the productivity characters were correlated by multiple variance analysis. The analysis permitted the identification of molecular markers associated with the cocoon weight or the shell weight separately. Some markers were associated with both characters.

Citation

http://www.ncbi.nlm.nih.gov/pubmed/16502509 PMID: 19537986 [PubMed - indexed for MEDLINE]

 

Title

A genome-wide survey for host response of silkworm, Bombyx mori during pathogen Bacillus bombyseptieus infection. Free PMC Article

Authors

Huang L, Cheng T, Xu P, Cheng D, Fang T, Xia Q.

 

Institute of Sericulture and Systems Biology, Southwest University, Chongqing, China.

Journal

PLoS One. 2009 Dec 1;4(12):e8098.

Abstract

Host-pathogen interactions are complex relationships, and a central challenge is to reveal the interactions between pathogens and their hosts. Bacillus bombysepticus (Bb) which can produces spores and parasporal crystals was firstly separated from the corpses of the infected silkworms (Bombyx mori). Bb naturally infects the silkworm can cause an acute fuliginosa septicaemia and kill the silkworm larvae generally within one day in the hot and humid season. Bb pathogen of the silkworm can be used for investigating the host responses after the infection. Gene expression profiling during four time-points of silkworm whole larvae after Bb infection was performed to gain insight into the mechanism of Bb-associated host whole body effect. Genome-wide survey of the host genes demonstrated many genes and pathways modulated after the infection. GO analysis of the induced genes indicated that their functions could be divided into 14 categories. KEGG pathway analysis identified that six types of basal metabolic pathway were regulated, including genetic information processing and transcription, carbohydrate metabolism, amino acid and nitrogen metabolism, nucleotide metabolism, metabolism of cofactors and vitamins, and xenobiotic biodegradation and metabolism. Similar to Bacillus thuringiensis (Bt), Bb can also induce a silkworm poisoning-related response. In this process, genes encoding midgut peritrophic membrane proteins, aminopeptidase N receptors and sodium/calcium exchange protein showed modulation. For the first time, we found that Bb induced a lot of genes involved in juvenile hormone synthesis and metabolism pathway upregulated. Bb also triggered the host immune responses, including cellular immune response and serine protease cascade melanization response. Real time PCR analysis showed that Bb can induce the silkworm systemic immune response, mainly by the Toll pathway. Anti-microorganism peptides (AMPs), including of Attacin, Lebocin, Enbocin, Gloverin and Moricin families, were upregulated at 24 hours post the infection.

Citation

http://www.ncbi.nlm.nih.gov/pubmed/19956592

PMID: 19956592 [PubMed - indexed for MEDLINE]PMCID: PMC2780328

 

Title

Evaluation of economically important traits from sixteen parental strains of the silkworm Bombyx mori L (Lepidoptera: Bombycidae). Free Article

Authors

Zanatta DB, Bravo JP, Barbosa JF, Munhoz RE, Fernandez MA.

 

Department de Biologia Celular e Genética, University Estadual de Maringá, Maringá, PR, 87020-900. danizanatta@gmail.com

Journal

Neotrop Entomol. 2009 May-Jun;38(3):327-31.

Abstract

The classification and characterization of silkworm strains are important for sericulture, which is supported by the constant development of new hybrids. In this study, 16 parental strains of Bombyx mori L from the germplasm banks of the Universidade Estadual de Maringá--UEM, and Associação dos Criadores de Bicho-da-Seda de Nova Esperança e Regiões Sericícolas do Paraná--ACESP, were evaluated regarding biological and productive traits economically important. The Chinese C122-B and C121-A, and the Japanese HA-A and HA-B strains yielded the highest cocoon weight, which is related to the raw silk percentage. Our data will be useful in breeding programs for the production of superior silkworm strains and hybrids.

Citation

http://www.ncbi.nlm.nih.gov/pubmed/19618047 PMID: 19618047 [PubMed - indexed for MEDLINE]

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