Calcium (Ca⁺²) regulates many cellular and physiological processes from development to reproduction. Ca⁺² is also an important factor in the metabolism of lipids, the primary energy source used during insect starvation and diapause. Ca²⁺ signaling proteins bind to Ca²⁺ and maintain intracellular Ca²⁺ levels. However, knowledge about Ca²⁺ signaling proteins is mostly restricted to the model Drosophila melanogaster and the response of Ca²⁺ signaling genes to starvation or diapause is not known. In this study, we identified three Ca²⁺ signaling proteins; the primary Ca²⁺ binding protein Calmodulin (LdCaM), phosphatase Calcineurin B (LdCaNB), and the senescence marker protein Regucalcin (LdRgN), from the fat body of the Colorado Potato Beetle, Leptinotarsa decemlineata (Coleoptera: Chrysomelidae). This insect is a major pest of potato worldwide and overwinters under hibernation diapause as adults while utilizing lipids as the primary energy source. Putative EF-hand domains involved in Ca⁺² binding were present in LdCaM, LdCaNB, but absent in LdRgN. LdCaM and LdCaNB were expressed in multiple tissues, while LdRgN was primarily expressed in the fat body. LdCaM was constitutively-expressed throughout larval development and at the adult stage. LdCaNB was primarily expressed in feeding larvae, and LdRgN in both feeding larvae and adults at comparable levels; however, both genes were down-regulated by molting. A response to starvation was observed only for LdRgN. Transcript abundance analysis in the entire body in relation to diapause revealed differential regulation with a general suppression during diapause, and higher mRNA levels in favor of females at post-diapause for LdCaM, and in favor of males at non-diapause for LdCaNB. Fat body-specific transcript abundance was not different between non-diapause and post-diapause for LdCaNB, but both LdCaM and LdRgN were down-regulated in males and both sexes, respectively by post-diapause. Silencing LdCaNB or LdRgN in larvae led to decreased fat content, indicating their involvement in lipid accumulation, while RNAi of LdCaM led to lethality.

钙 (Ca ⁺² ) 调节从发育到繁殖的许多细胞和生理过程。Ca ⁺²也是脂类代谢的重要因素，脂类是昆虫饥饿和滞育期间使用的主要能量来源。Ca ²⁺信号蛋白与Ca ²⁺结合并维持细胞内Ca ²⁺水平。然而，关于 Ca ²⁺信号蛋白的知识主要限于模型果蝇，并且 Ca ²⁺信号基因对饥饿或滞育的反应尚不清楚。在这项研究中，我们鉴定了三种 Ca ²⁺信号蛋白；初级Ca ²⁺结合蛋白钙调蛋白 (LdCaM)、磷酸酶钙调磷酸酶 B (LdCaNB) 和衰老标记蛋白 Regucalcin (LdRgN)，来自科罗拉多马铃薯甲虫的脂肪体，Leptinotarsa decemlineata（鞘翅目：Chrysomelidae）。这种昆虫是世界范围内马铃薯的主要害虫，成年后在冬眠滞育下越冬，同时利用脂质作为主要能源。参与 Ca ⁺²结合的假定EF 手结构域存在于 LdCaM、LdCaNB 中，但不存在于 LdRgN 中。LdCaM和LdCaNB在多种组织中表达，而LdRgN主要在脂肪体中表达。LdCaM在整个幼虫发育和成虫阶段组成型表达。LdCaNB主要在喂养幼虫中表达，而LdRgN在喂养幼虫和成虫中的表达水平相当；然而，这两个基因都被蜕皮下调。仅观察到LdRgN对饥饿的反应。与滞育相关的全身转录本丰度分析揭示了在滞育期间普遍抑制的差异调节，以及更高的 mRNA 水平有利于LdCaM滞育后的女性，而LdCaNB 则有利于非滞育的男性。非滞育和滞育后LdCaNB 的脂肪体特异性转录本丰度没有差异，但LdCaM和LdRgN通过滞育后分别在男性和两性中下调。在幼虫中沉默LdCaNB或LdRgN导致脂肪含量降低，表明它们参与脂质积累，而LdCaM 的RNAi导致致死率。