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

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, 9:25 AM by rajesh gk

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

[Comparison of early embryogenesis between silkworm and Drosophila from both morphology and gene content level]

[Article in Chinese]

Authors

Chai CL, Lu C.

Key Laboratory of Sericulture of the Agriculture Ministry of China, Southwest University, Chongqing, China. chail@swau.cq.cn

Journal

Yi Chuan. 2006 Sep;28(9):1173-9.

Abstract

The diversity of insects has been the focus of many investigations. Research in the early embryonic developmental mechanism of silkworm will promote understanding in early embryonic developmental mechanism of other insects. This paper reviews the differences in early embryonic development of silkworm and Drosophila from both morphology and gene content level. The results not only provide evidences for the study of early embryonic development mechanism in silkworm, but also give clues for the study of insects diversity.

Citation

http://www.ncbi.nlm.nih.gov/pubmed/16963431 PMID: 16963431 [PubMed - indexed for MEDLINE]

 

Title

Expression of heat shock protein 70a mRNA in Bombyx mori diapause eggs.

Authors

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

 

Sericulture & Entomoresources, Graduate School of Bioagricultural Sciences, Nagoya University, Chikusa, Nagoya 464-8601, Japan.

Journal

J Insect Physiol. 2010 Apr 10. [Epub ahead of print]

Abstract

In an effort to understand whether heat shock protein 70 (Hsp70) participates in the environmental 5 degrees C signal reception/transduction toward breaking embryonic diapause of the silkworm Bombyx mori, we isolated a cDNA for Hsp70a and examined the expression of Hsp70a mRNA in B. mori diapause and nondiapause eggs by quantitative real-time PCR. Hsp70a mRNA gradually increased in diapause eggs continuously kept at 25 degrees C after oviposition to maintain diapause. When diapause eggs were exposed to the diapause-terminating condition of 5 degrees C beginning at 2 days post-oviposition, Hsp70a mRNA increased beginning at 5 days post-cold treatment. Even in nondiapause eggs, Hsp70a mRNA increased slightly with exposure to 5 degrees C. These results suggest that Hsp70a is involved in reception/transduction of the diapause-terminating (5 degrees C) signal via gene activation. The expression patterns of Hsp70a mRNA are discussed in relation to those of the cold-response gene Samui. Copyright © 2010 Elsevier Ltd. All rights reserved.

Citation

http://www.ncbi.nlm.nih.gov/pubmed/20371249 PMID: 20371249 [PubMed - as supplied by publisher]

posted Jul 5, 2010, 2:19 AM by rajesh gk

Title

Shotgun proteomic analysis on the embryos of silkworm Bombyx mori a t the end of organogenesis.

Authors

Li JY, Moghaddam SH, Chen JE, Chen M, Zhong BX.

 

College of Animal Sciences, Zhejiang University, Hangzhou 310029, PR China.

Journal

Insect Biochem Mol Biol. 2010 Apr;40(4):293-302. Epub 2010 Feb 4.

Abstract

Embryonic development of silkworm, Bombyx mori is a process of systematical expression of genes and proteins which is dominated by complex regulatory networks. To gain comprehensive insight into the molecular basis of embryonic development and its regulation mechanisms, the proteome profile of the B. mori embryos at the end of organogenesis (tubercle appearance stage, TA) was characterized using LTQ-Orbitrap mass spectrometer. Totally 963 proteins were identified with a false discovery rate (FDR) of 0.12%. They were involved in embryonic development, chemoreception, and stimuli response and so forth. The proteins with the largest number of identified unique peptides, implying their possibly higher abundance, were involved in heat shock response, lipid transport and metabolism, and apoptosis. It was consistent with the physiological status of embryo at the end of organogenesis. Many functionally important proteins were identified for the first time in B. mori embryo such as the progesterone receptor membrane component 2, antennal binding protein, sericotropin, and molting fluid carboxypeptidase A (MF-CPA). 253 (26.27%) specific proteins in TA versus labrum appearance stage (LA, four days before TA) embryos were identified, which were mainly associated with musculature, nervous system, and chemoreception system. They disclosed the differential temporal and spatial expression of proteins in the process of organogenesis. The relative mRNA levels of fifteen identified proteins in the two experimented stages were also compared using quantitative reverse transcription PCR (qRT-PCR) and showed some inconsistencies with protein expression. Gene Ontology (GO) annotation of the identified proteins showed that the most proteome representations were in the categories of "binding" and "catalytic" in molecular function, and "cellular process" and "metabolic process" in biological process. Copyright (c) 2010 Elsevier Ltd. All rights reserved.

Citation

PMID: 20138214 [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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