Rhodnius prolixus, a vector of Chagas disease, is a hematophagous insect that feeds exclusively on blood. Each blood meal is digested within the first fourteen days after feeding, providing substrates for lipid synthesis for storage and egg production. These events are precisely regulated and emerging evidence points to a key function of insulin-like peptides (ILPs) in this control. Here we investigated the role of insulin receptor in the regulation of nutrient metabolism in fed adult females. The expression of insulin receptor (RhoprIR) gene was determined in adult organs, and it was highest in ovaries and previtellogenic follicles. We generated insects with RNAi-mediated knockdown of RhoprIR to address the physiological role of this receptor. RhoprIR deficiency improved longevity and reduced triacylglycerol storage in the fat body, whereas blood digestion remained unchanged for seven days after blood meal. The lower lipid content was attributable to decreased de novo lipogenesis as well as reduced incorporation of hemolymph-derived fatty acids into newly synthesized lipids within this organ. Consistent with that, fat bodies from RhoprIR-deficient insects exhibited decreased gene expression levels of lipophorin receptor (RhoprLpR), glycerol-3-phosphate acyltransferase 1 and 4 (RhoprGpat1 and RhoprGpat4), and carnitine palmitoyltransferase 1 (RhoprCpt1). Although hemolymph lipid profile was not affected by RhoprIR disruption, the concentration of circulating vitellogenin was increased. In line with these changes, RhoprIR-deficient females exhibited smaller ovaries and a marked reduction in oviposition. Taken together, these findings support a key role of insulin receptor in nutrient homeostasis, lipid synthesis and egg production following a blood meal.

Rhodnius prolixus是南美锥虫病的传播媒介，是一种完全以血液为食的吸血昆虫。每份血粉在喂食后的前 14 天内被消化，为脂质合成提供底物，用于储存和产蛋。这些事件受到精确调控，新出现的证据表明胰岛素样肽 (ILP) 在该控制中的关键功能。在这里，我们研究了胰岛素受体在调节喂养成年女性营养代谢中的作用。胰岛素受体（RhoprIR）基因在成人器官中的表达，在卵巢和卵黄前卵泡中表达最高。我们用 RNAi 介导的RhoprIR敲低产生了昆虫，以解决这种受体的生理作用。RhoprIR缺乏可延长寿命并减少脂肪体中的甘油三酯储存，而血液消化在血餐后 7 天保持不变。较低的脂质含量归因于从头脂肪生成减少以及血淋巴衍生脂肪酸掺入该器官内新合成的脂质中的减少。与此一致，来自RhoprIR 缺陷昆虫的脂肪体表现出脂蛋白受体 ( RhoprL p R)、3-磷酸甘油酰基转移酶 1 和 4 ( RhoprGpat1和RhoprGpat4 ) 以及肉碱棕榈酰转移酶 1 ( RhoprCpt1 )的基因表达水平降低）。尽管血淋巴脂质谱不受RhoprIR破坏的影响，但循环卵黄原蛋白的浓度增加了。与这些变化一致，RhoprIR 缺陷的雌性表现出较小的卵巢和产卵量的显着减少。总之，这些发现支持胰岛素受体在血餐后营养稳态、脂质合成和产卵中的关键作用。