• International Journal of Industrial Entomology and Biomaterials
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• v.23 no.1
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• pp.137-141
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• 2011

A previous data was provided information for tissuespecific expression genes by means of whole-genome oligonucleotide microarray in the silkworm. We analyzed the tissue-specific expression patterns in the hemocyte tissue on 5 days of 5th instar larvae during the development of $B.$ $mori$. Total 5 candidates pick out from the $Bombyx$ $mori$ Microarray Database (BmMDB; http://silkworm.swu.edu.cn/microarray). To verify the hemocyte-specific expression, we analyzed by semi-quantitative and real-time quantitative RT-PCR using the highly expressed endogenous $Actin$ RNA as an intrinsic reference. In this study, we confirmed that one gene-sw17255- out of 5 candidates expressed in the hemocyte tissue, which was consistent with the previous data. Circulating hemocytes in the body fluid of the $B.$ $mori$ are most powerful target organ for producing biomaterials. We need further studies to find hemocyte-specific promoter region from sw17255 gene. Finally, this result can be applied in creating transgenic silkworms as a biomedical insect.

• Journal of Microbiology and Biotechnology
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• v.19 no.6
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• pp.610-615
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• 2009

As a provirus, polydnavirus has a segmented DNA genome on chromosome(s) of host wasp. It contains several genes in each segment that presumably play critical roles in regulating physiological processes of target insect parasitized by the wasp. A cysteine-rich protein 1 (CRP1) is present in the polydnavirus Cotesia plutellae bracovirus (CpBV) genome, but its expression and physiological function in Plutella xylostella parasitized by the viral host C. plutellae is not known. This CpBV-CRP1 encoding 189 amino acids with a putative signal peptide (20 residues) was persistently expressed in parasitized P. xylostella with gradual decrease at the late parasitization period. Expression of CpBV-CRP1 was tissue-specific in the fat body/epidermis and hemocyte, but not in the gut. Its physiological function was analyzed by inducing transient expression of a CpBV segment containing CpBV-CRP1 and its promoter, which caused significant reduction in hemocyte -spreading and delayed larval development. When the treated larvae were co-injected with double-stranded RNA of CpBV-CRP1, the expression of CpBV-CRP1 disappeared, whereas other genes encoded in the CpBV segment was expressed. These co-injected larvae significantly recovered the hemocyte-spreading capacity and larval development rate. This study reports that CpBV-CRP1 is expressed in P. xylostella parasitized by C. plutellae and its physiological function is to alter the host immune and developmental processes.

• International Journal of Industrial Entomology and Biomaterials
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• v.25 no.1
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• pp.111-114
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• 2012

In previous studies we have shown that a sw17255 gene was expressed in hemocyte-specific tissues of the silkworm, Bombyx mori L. (Lepidoptera: Bombycidae). It was verified that the sw17255 core promoter region contains elements that regulate the expression of this gene in hemocyte tissue; the selected promoter region spans nucleotides -1 to -2,112 upstream of the start codon. Each of the luciferase reporter gene expression vectors under the control of 4 different kinds of promoter candidates, (-2,112/-1), (-1,640/-1), (-1,169/-1) and (-579/-1), and the control reporter plasmid DNA, were introduced into B. mori larval coelom by direct injection using a syringe. The promoter candidate [E] (-579/-1) showed more than 1.67 fold transcriptional activity compared to control promoter activity. Higher productivity of an expressed gene in the transgenic silkworm by this promoter combination could be achieved in the near future. The foreign recombinant protein could be easily harvested from the blood of the transgenic silkworm.