Wang Nianmeng, Wang Zijian, Gong Siyuan, Zhang Yashu, Xue Chaobin
Ministry of Agriculture and Rural Affairs Key Laboratory of Lower Yellow River Crop Integrated Pest Management, College of Plant Protection, Shandong Agricultural University, Tai'an, Shandong, China.
Insect Sci. 2024 Oct 14. doi: 10.1111/1744-7917.13463.
Insulin-like peptides (ILPs) act as crucial reproductive neuropeptides in insects, regulating insect reproduction through the insulin signaling pathway (ISP). Our previous studies have found that the sublethal concentrations (LC and LC) of lambda-cyhalothrin (λCy) could induce severe reproductive toxicity in the lacewing, Chrysoperla sinica (Tjeder), but the toxicological mechanism remains unclear. This study discovered that λCy could inhibit CsILP transcription, leading to a decrease in insulin content and downregulation of C. sinica insulin receptor (CsInR) and C. sinica forkhead box O (CsFOXO) expression in ISP. Interference with CsILP expression resulted in downregulation of C. sinica vitellogenin (CsVg) and decreasing fecundity, while exogenous injection of bovine insulin promoted upregulation of CsVg expression and facilitated reproduction in female adults of C. sinica. Meanwhile, interference with FOXO of ILP downstream transcription factor could lead to downregulation of CsVg, hindering ovarian development and resulting in a decrease in egg production. However, exogenous injection of bovine insulin could remedy the effects caused by FOXO interference. In addition, ILP mediates juvenile hormone and 20-hydroxyecdysone biosynthesis by acting on their synthetic regulatory enzymes and influences the signal transduction of the 2 reproductive endocrine hormones, thereby regulating the reproductive endocrine environment in C. sinica. In conclusion, λCy inhibits CsILP expression, leading to disorder of ISP, leading to the reduced fecundity of C. sinica.
胰岛素样肽（ILPs）在昆虫中作为关键的生殖神经肽，通过胰岛素信号通路（ISP）调节昆虫繁殖。我们之前的研究发现，高效氯氟氰菊酯（λCy）的亚致死浓度（LC 和 LC）可诱导中华草蛉（Chrysoperla sinica (Tjeder)）产生严重的生殖毒性，但其毒理学机制仍不清楚。本研究发现，λCy 可抑制 CsILP 的转录，导致胰岛素含量降低，以及中华草蛉胰岛素受体（CsInR）和中华草蛉叉头框 O（CsFOXO）在 ISP 中的表达下调。干扰 CsILP 的表达导致中华草蛉卵黄原蛋白（CsVg）下调和繁殖力下降，而外源注射牛胰岛素可促进 CsVg 表达上调并促进中华草蛉雌成虫的繁殖。同时，干扰 ILP 下游转录因子 FOXO 可导致 CsVg 下调，阻碍卵巢发育并导致产卵量减少。然而，外源注射牛胰岛素可弥补 FOXO 干扰所造成的影响。此外，ILP 通过作用于其合成调节酶介导保幼激素和 20-羟基蜕皮激素的生物合成，并影响这两种生殖内分泌激素的信号转导，从而调节中华草蛉的生殖内分泌环境。总之，λCy 抑制 CsILP 的表达，导致 ISP 紊乱，从而导致中华草蛉繁殖力降低。
