Abstract：
Bombyx mori L. (Lepidoptera: Bombycidae) nucleopolyhedrovirus (BmNPV) is a serious pathogen causing huge economic losses to sericulture. There is growing evidence that the gut microbiota of silkworms plays a critical role in shaping host responses and interactions with viral infection. However, little is known about the differences in the composition and diversity of intestinal microflora, especially with respect to silkworm strain differences and BmNPV infection-induced changes. Here, we aim to explore the differences between BmNPV-resistant strain A35 and susceptible strain P50 silkworm and the impact of BmNPV infection on intestinal microflora in different strains. The 16S rDNA sequencing analysis revealed that the fecal microbial populations were distinct between A35 and P50 and were significantly changed post BmNPV infection in both strains. Further analysis showed that the BmNPV-resistant strain silkworm possessed higher bacterial diversity than the susceptible strain, and BmNPV infection reduced the diversity of intestinal flora assessed by feces in both silkworm strains. In response to BmNPV infection, the abundance of Muribaculaceae increased in P50 and decreased in A35, while the abundance of Enterobacteriaceae decreased in P50 and increased in A35. These results indicated that BmNPV infection had various effects on the abundance of fecal microflora in different silkworm strains. Our findings not only broadened the understanding of host-pathogen interactions but also provided theoretical help for the breeding of resistant strains and healthy rearing of silkworms based on symbiotic bacteria.
摘要：
BombyxmoriL.（鳞翅目：Bombycidae）核多角体病毒（BmNPV）是一种严重的病原体，给养蚕造成了巨大的经济损失。越来越多的证据表明，家蚕的肠道微生物群在塑造宿主反应和与病毒感染的相互作用中起着关键作用。然而,人们对肠道菌群的组成和多样性知之甚少，特别是关于家蚕品系差异和BmNPV感染引起的变化。这里,目的探讨家蚕BmNPV抗性株A35与敏感株P50的差异及BmNPV感染对不同菌株肠道菌群的影响。16SrDNA测序分析表明，A35和P50之间的粪便微生物种群不同，并且在两种菌株中BmNPV感染后都发生了显着变化。进一步分析表明，BmNPV抗性菌株家蚕比易感菌株具有更高的细菌多样性，和BmNPV感染降低了两种家蚕菌株通过粪便评估的肠道菌群多样性。为了应对BmNPV感染，在P50中，Muribaculaceae的丰度增加，在A35中减少，而肠杆菌科的丰度在P50中减少，在A35中增加。这些结果表明，BmNPV感染对不同家蚕菌株粪便微生物区系的丰度有不同的影响。我们的发现不仅拓宽了对宿主-病原体相互作用的理解，而且为基于共生细菌的家蚕抗性菌株的选育和健康饲养提供了理论帮助。
