• International Journal of Industrial Entomology and Biomaterials
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• v.33 no.2
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• pp.113-120
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• 2016

Bombyx mandarina is widely accepted as ancestor of B. mori. Silkworms are served as well-characterized models for understanding the mechanism for the genetic regulation of development. In this study, we performed RNA-Seq analysis to examine tissue-expression of gloverin isoforms of the silk-gland, mid-gut, and fat body in B. mandarina. BLAST analysis revealed that four gloverin isoform gene sequences of B. mandarina were highly similar to B. mori. To identify the difference between two species, the expression profile of gloverin was measured by semi- RT-PCR analysis. The specific expression of gloverin isoform genes was observed mainly in the fat body from B. mori but not B. mandarina. However, all of tissues in the wild-type silkworm could induce the upregulation of compared with the B. mori. To validate the sudden increase in gloverin gene expression in the mid-gut tissue of B. mandarina, we were using qRT-PCR. Relative mRNA expression rate of gloverin at the wild-type silkworm was much higher than domestic silkworm. Comparative genomics between domesticated and wild silkworms showed different tissue-expression levels in some of immune related genes. These results are suggesting a trend toward decreasing immunity related genes expression during domestication. Further studies are needed to elucidate the silkworm domestication and an invaluable resource for wild silkworm genomics research.

• International Journal of Industrial Entomology and Biomaterials
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• v.29 no.2
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• pp.145-152
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• 2014

The variation in the level of immune response related gene expression in silkworm, Bombyx mori following infection with Bombyx mori nucleopolyhedrovirus (BmNPV) was analyzed at different time intervals. The occlusion bodies of BmNPV orally inoculated to the two most divergent silkworm races viz., Sarupat (resistant to BmNPV infection) and CSR2 (susceptible to BmNPV infection) were subjected to oral BmNPV inoculation. The expression profile of gp 41 gene of BmNPV in the Sarupat and CSR2 races revealed that the virus could invade the midguts of both susceptible and resistant races. However, its multiplication was significantly less in the midgut of resistant race, while, in the susceptible race, the viral multiplication reached maximum level within 12 h. These findings indicate that potential host genes are involved in the inhibition of viral multiplication within larval midgut. The immune response genes arylphorin, cathepsin B, gloverin, lebocin, serpin, Hsp 19.9, Hsp 20.1, Hsp 20.4, Hsp 20.8, Hsp 21.4, Hsp 23.7, Hsp 40, Hsp 70, Hsp90 revealed differential level of expression on NPV infection. The gloverin, serpin, Hsp 23.7 and Hsp 40 genes are significantly up-regulated in the resistant race after NPV infection. The early up-regulation of these genes suggests that these genes could play an important role in baculovirus resistance in the silkworm, B. mori.

• Journal of Life Science
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• v.26 no.6
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• pp.737-748
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• 2016

By this time, insect antimicrobial peptides (AMPs) have been characterized more than 150 peptides since purification of cecropin in the hemolymph of pupae from Hyalophora cecropia in 1980. Therefore, it is considered that insects are good sources of AMP selection. Insect AMPs are small (low molecular weight) and cationic, and amphipathic with variable length, sequence, and structure. They perform a pivotal role on humoral immunity in the insect innate immune system against invading pathogens such as bacteria, fungi, parasites, and viruses. Most of the insect AMPs are induced rapidly in the fat bodies and other specific tissues of insects after septic injury or immune challenge. Then the AMPs subsequently released into the hemolymph to act against microorganisms. These peptides have a broad antimicrobial spectrum against various microbes including anticancer activities. Insect AMPs could be divided into four families based on their structures and sequences. That is the α-helical peptides, cysteine-rich peptides, proline-rich peptides, and glycine-rich peptides/proteins. For instance, cecropins, insect defensins, proline-rich peptides, and attacins are common insect AMPs, but gloverins and moricins have been identified only in lepidopteran species. This review focuses on AMPs from insects and discusses current knowledge and recent progress with potential applications of insect AMPs.