Study On The Function Of Insulin Signaling In Reproductive Diapause Of Colaphellus Bowringi

Insulin signaling pathway(IIS)is an important hormone regulation pathway in insects,which plays an important role in regulating insect lifespan,metabolism and accumulation of nutrients.Studies have shown that IIS can induce short-day diapause insects into reproductive diapause,but the molecular mechanism is unclear.In addition,it is not known whether IIS mediates long-day induced reproductive diapause through similar mechanisms.In this study,long-day induces the Colaphellus bowringi Baly to enter reproductive diapause.Screen and clone the IIS key genes of C.bowringi,and explore the molecular mechanism of IIS regulating the reproductive diapause in C.bowringi.The main conclusions are as follows:1.Cloning and sequence analysis of IIS key genes of C.bowringi.The full-length c DNA sequences of ILPs(ILP1,ILP2,ILP3),In R(In R1,In R2),IRS,PI3 K and AKT genes were successfully cloned.Analysis showed that the key genes of the insulin signaling pathway in C.bowringi are most closely related to the corresponding genes in Coleoptera,and have the same and conserved functional domains as other species.2.Temporal expression pattern of IIS key genes in the head of C.bowringi.Analysis and comparison the differences in the expression of the IIS key genes in the heads of 8-day-old larvae,1,2,3-day-old female pupae and female adult under the conditions of reproductive and diapause.It was found that the expression of ILP1,ILP3,In R1,IRS,PI3 K,and AKT were significantly higher under reproductive conditions,suggesting that these genes may regulate reproductive diapause in C.bowringi.3.Study on the function of IIS key genes in reproductive diapause of C.bowringi.Under reproductive conditions,it was found that silencing In R1,IRS,PI3 K,and AKT all caused the ovarian poorly development and fat body accumulation in the pupal of C.bowringi.Only the diapause phenotype after In R1 silence can be successfully rescued by juvenile hormone analogues(Methoprene,JHA),and JHA has no obvious effect on the ovarian development blocked by IRS,PI3 K,or AKT.The disturbance of In Rs by 0-old-adult had no obvious effect on the ovaries and fat bodies of C.bowringi.This further implies that the IIS is involved in the signal transmission from the diapause induction period to the early diapause preparation in C.bowringi.In summary,in the long-day diapause C.bowringi,the low-level insulin signal(In R1-IRS-PI3K-AKT)at the end of diapause-induced inhibited the development of female adult ovaries and promoted the accumulation of lipids.At the same time,In R1 can act on JH signaling to regulate ovarian development and lipid accumulation during diapause preparation.However,the regulation mechanism of ?IRS-PI3K-AKT? on ovarian development and lipid accumulation is still not clear.This study reveals the role of IIS in the induction of reproductive diapause in long-day diapause insects,and provides new molecular targets and theoretical guidance for the formulation of pest control strategies based on diapause regulation.