Abstract：
The infection caused by Nosema bombycis often known as pebrine, is a devastating sericulture disease. The infection can be transmitted to the next generation through eggs laid by infected female Bombyx mori moths (transovarial) as well as with N. bombycis contaminated food (horizontal). Most diagnoses were carried out in the advanced stages of infection until the time that infection might spread to other healthy insects. Hence, early diagnosis of pebrine is of utmost importance to quarantine infected larvae from uninfected silkworm batches and stop further spread of the infection. The findings of our study provide an insight into how the silkworm larval host defence system was activated against early N. bombycis transovarial infection. The results obtained from transcriptome analysis of infected 2nd instar larvae revealed significant (adjusted P-value < 0.05) expression of 1888 genes of which 801 genes were found to be upregulated and 1087 genes were downregulated when compared with the control. Pathway analysis indicated activation of the immune deficiency (IMD) pathway, which shows a potential immune defence response against pebrine infection as well as suppression of the melanin synthesis pathway due to lower expression of prophenoloxidase activating enzyme (PPAE). Liquid chromatography mass spectrometry (LC-MS/MS) analysis of haemolymph from infected larvae shows the secretion of serpin binding protein of N. bombycis which might be involved in the suppression of the melanization pathway. Moreover, among the differentially expressed genes, we found that LPMC-61, yellow-y, gasp and osiris 9 can be utilised as potential markers for early diagnosis of transovarial pebrine infection in B. mori. Physiological as well as biochemical roles and functions of many of the essential genes are yet to be established, and enlightened research will be required to characterize the products of these genes.
摘要：
由Bombyccis引起的感染通常被称为peprosin，是一种毁灭性的蚕桑病。感染可以通过受感染的雌性家蚕蛾（跨静脉曲张）以及受家蚕污染的食物（水平）产下的卵传播给下一代。大多数诊断是在感染的晚期阶段进行的，直到感染可能传播到其他健康昆虫。因此，pebalm的早期诊断对于从未感染的家蚕批次中隔离感染的幼虫并阻止感染的进一步传播至关重要。我们的研究结果提供了有关如何激活家蚕幼虫宿主防御系统以抵抗早期N.Bombycis经静脉曲张感染的见解。从受感染的第二龄幼虫的转录组分析获得的结果表明，与对照相比，1888个基因的表达显着（调整后的P值<0.05），其中801个基因被上调，而1087个基因被下调。路径分析显示免疫缺陷（IMD）途径激活，由于酚氧化酶原激活酶（PPAE）的较低表达，其显示出针对pebalin感染的潜在免疫防御反应以及黑色素合成途径的抑制。受感染幼虫血淋巴的液相色谱质谱（LC-MS/MS）分析显示，家蚕原虫serpin结合蛋白的分泌可能与黑化途径的抑制有关。此外，在差异表达的基因中，我们发现LPMC-61，黄色，喘气和osiris9可以用作早期诊断B.mori经静脉曲张感染的潜在标志物。许多必需基因的生理和生化作用和功能尚未建立，需要开明的研究来表征这些基因的产物。
