Abstract:Bombyx mori nucleopolyhedrovirus (BmNPV) is a highly pathogenic virus in the sericultural industry and often results in severe economic losses. Some proteins are found to show antiviral activity against BmNPV in previous studies, but little is known about the correlations between expression levels of these antiviral related genes and resistance abilities of different genetic materials against BmNPV. In this study, to explore the correlations, the highly resistant parent (R) was crossed with the highly susceptible parent (S) to generate different types of genetic materials such as F1, F2, and backcrosses. The resistance to BmNPV and the corresponding relative expression levels of 5 antiviral related genes including Bmlipase-1, serine protease Ⅱgene (BmSP-2), ribosomal protein S3A gene (BmS3A), suppressor of profilin 2 gene (BmSop2) and nicotinamide adenine dinucleotide phosphate oxidoreductase gene (BmNOX) in different genetic materials were detected by BmNPV attack test and fluorescent quantitative PCR (qRT-PCR) technology.The results showed that BmSP-2 and Bmlipase-1 specifically expressed in midgut, other genes showed no tissue specificity. The relative expression levels of 4 genes (Bmlipase-1, BmSP-2, BmNOX and BmSop2) were higher in midguts of different types of genetic materials with stronger viral resistance, which had significant differences in different types of genetic materials, being consistent with their resistance abilities. However, there was no correlation among the expression levels of BmS3A. The highest level of consistency between expression levels of these antiviral related genes and resistance abilities of different types of genetic materials against BmNPV had been observed in Bmlipase-1. It was concluded that relative expression levels of Bmlipase-1 could be one of the basis in selecting anti -BmNPV materials in silkworm breeding.
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