PDF(Pubmed)
Abstract：
Insulin receptor substrate (IRS) proteins are key mediators in insulin signaling pathway. In social insect lives, IRS proteins played important roles in caste differentiation and foraging, but there function in disease defenses such as active immunization has not been reported yet. To investigate the issue, we successfully suppressed the IRS gene 3 days after dsRNA injection. Suppressing IRS gene increased the contents of glucose, trehalose, glycogen, and triglyceride and decreased the content of pyruvate in termites, and led to the metabolic disorder of glucose and lipids. IRS suppressing significantly enhanced grooming behaviors of nestmates of fungus-contaminated termites and hence increased the conidial load in the guts of the nestmates. Additionally, IRS suppressing led to significant downregulation of the immune genes Gram-negative bacteria-binding protein2 (GNBP2) and termicin and upregulation of the apoptotic gene caspase8, and hence diminished antifungal activity of nestmates of fungus-contaminated termites. The above abnormal behavioral and physiological responses significantly decreased the survival rate of dsIRS-injected nestmates of the fungus-contaminated termites. These findings suggest that IRS is involved in regulation of active immunization in termites, providing a better understanding of the link between insulin signaling and the social immunity of termites.
摘要：
胰岛素受体底物（IRS）蛋白是胰岛素信号通路中的关键介质。在社会昆虫的生活中，IRS蛋白在种姓分化和觅食中发挥重要作用,但是在疾病防御中的功能，如主动免疫尚未报道。为了调查这个问题，我们在dsRNA注射后3天成功抑制了IRS基因。抑制IRS基因增加葡萄糖的含量，海藻糖,糖原，和甘油三酯，降低白蚁中丙酮酸的含量，并导致葡萄糖和脂质的代谢紊乱。IRS抑制真菌污染的白蚁的巢穴的修饰行为显着增强，因此增加了巢穴的分生孢子负荷。此外,IRS抑制导致免疫基因革兰氏阴性细菌结合蛋白2（GNBP2）和termicin的显着下调和凋亡基因caspase8的上调，从而降低了受真菌污染的白蚁巢穴的抗真菌活性。上述异常的行为和生理反应显着降低了被真菌污染的白蚁的dsIRS注射巢的存活率。这些发现表明，IRS参与白蚁主动免疫的调节，更好地了解胰岛素信号和白蚁的社会免疫力之间的联系。
