Differential Level of Host Gene Expression Associated with Nucleopolyhedrovirus Infection in Silkworm Races of Bombyx mori

The variation in the level of immune response related gene expression in silkworm, Bombyxmori following infection with Bombyx mori nucleopolyhedrovirus (BmNPV) was analyzed atdifferent time intervals. The occlusion bodies of BmNPV orally inoculated to the two mostdivergent silkworm races viz., Sarupat (resistant to BmNPV infection) and CSR2 (susceptibleto BmNPV infection) were subjected to oral BmNPV inoculation. The expression profile ofgp 41 gene of BmNPV in the Sarupat and CSR2 races revealed that the virus could invade themidguts of both susceptible and resistant races. However, its multiplication was significantlyless in the midgut of resistant race, while, in the susceptible race, the viral multiplicationreached maximum level within 12 h. These findings indicate that potential host genes areinvolved in the inhibition of viral multiplication within larval midgut. The immune responsegenes arylphorin, cathepsin B, gloverin, lebocin, serpin, Hsp 19.9, Hsp 20.1, Hsp 20.4, Hsp20.8, Hsp 21.4, Hsp 23.7, Hsp 40, Hsp 70, Hsp90 revealed differential level of expression onNPV infection. The gloverin, serpin, Hsp 23.7 and Hsp 40 genes are significantly up-regulatedin the resistant race after NPV infection. The early up-regulation of these genes suggests thatthese genes could play an important role in baculovirus resistance in the silkworm, B. mori. KCI Citation Count: 0