Bioinformatic Analysis And RNAi Study Of The Insulin Receptor In Neoseiulus Barkeri

Neoseiulus barkeri is a natural enemy widely used in the control of small sucking pests and mites.The stability of population in the process of propagation and long-distance transportation has always been one of the factors affecting its utilization effect.Therefore,it is particularly important to find out a feeding method with long shelf life and high survival rate.In this study,we investigated the effects of insulin receptor on the growth and reproductive diapause of N.barkeri.We analyzed the c DNA sequence of Nb In R and the expression patterns of Nb PI3 K,Nb PIP2 and Nb Fox O,which provided a basis for further exploring the relationship between insulin receptor and the reproductive diapause of N.barkeri.The main findings are as follows:Through bioinformatics analysis of In R gene of N.barkeri,it was found that the amino acid sequence of Nb In R gene was the most closest to that of Galendromus occidentalis.The open reading frame of Nb In R is 666 bp,and coding 222 aa,predicted relative molecular weight is 25220.41 Da,theoretical isoelectric point is 5.89,fat coefficient is91.97,and total hydrophilic average(gravy)is-0.187.The analysis of signal peptide and hydrophobicity indicated that Nb In R was hydrophilic protein Compared with other species,Nb In R has the characteristics of tyrosine kinase superfamily.In this sequence,there is a protein kinase superfamily tyrosine kinase catalytic domain(Tyrkc).At the same time,there are 5'-AMP activated protein kinase ?-subdomain AMPAKI,serine / threonine protein kinase catalytic domain S?TKC,etc.The results of quantitative real-time reverse transcription polymerase chain reaction(RT-q PCR)showed that Nb Fox O was significantly expressed in diapause female adult mites,Nb In R was the highest expression in larva,followed by protonymph,while Nb PI3 K and Nb PIP2 were the highest expression in larva,and the lowest expression in diapause female adult mites.RNA interference of Nb In R gene,the results showed that the transcription level of Nb In R was significantly reduced,and the related genes Nb PIP2 and Nb PI3 K in the signaling pathway were also dramatically reduced,which indicated that Nb PIP2 gene and Nb PI3 K gene acted on the downstream of Nb In R,and In R gene activated the downstream PI3 K gene to play a regulatory role,while the transcription level of Nb Fox O did not change remarkably,which may be because Fox O transcription is not only regulated by insulin signaling pathway,but also regulated by other signaling pathways.The phenotypic analysis of N.barkeri after the interference showed that compared with the control group,the egg laying amount of N.barkeri treated with ds In R was reduced by about 29%,the developmental duration of protonymph to adult was prolonged about 30%,whereas the life span and egg hatchabilty were not statistically different.The results of examining the Vg gene expression showed that the silencing of Nb In R gene could reduce the transcription of vitellogenin gene,and the yolk particles could not be deposited in the ovary,which led to the decrease of oviposition.Therefore,Nb In R as a key factor of insulin signaling pathway,can regulate the growth and reproduction of N.barkeri.In addition,Nb In R gene can interact with other endogenous hormone signaling pathways to affect the transcription of genes related to diapause.