Expression Profile And Preliminary Function Analysis Of The Wax Ester Synthase Gene Of Ericerus Pela

The Chinese white wax scale insect(Ericerus pela)is an economically valuable species with an important role in white wax production.The white wax has been widely used in many fields,such as machinery,medical,food,cosmetics and so on.There is a conserved wax ester synthesis pathway in organisms: in the different organisms,the wax ester is synthetized by catalyticing fatty alcohols and fatty acyl-coenzyme A by wax synthase(WS).WS is the key synthase to generating wax ester.Based on the ws gene of E.pela indentified previously,we will study the gene expression profile,the gene function in vivo and WS enzyme activity in vitro.Real-time Quantitative PCR(RT-qPCR)technology,bac-to-bac insect expression system,and RNA interference(RNAi),were employed in this study.The results showed that,the ws gene expression in different periods and different tissues of male and female of E.pela was consist with wax secretion.WS of E.pela has the enzyme activity of wax synthesis,and the WS plays important role in the white wax ester synthesis of E.pela.The main results are as follows:(1)The expression profile showed that,the expression of ws gene in the 2 instar male larvae were upregulated dramaticly,and the gene expression in the cuticle was significantly higher than others tissues;(2)The dsRNA of ws gene were synthesized in vitro for RNA interference(RNAi).After RNAi,the ws gene expression was down-regulated.The quantity of wax secretion decreased after RNA interference compared to the blank control group and gfp dsRNA group;(3)WS was expressed in BmN cells by bac-to-bac expression system.Transfected the recombinant bacmid into BmN cells,and Western blot showed the expression level was higher at 36 hours;(4)The WS enzyme activity was detected after adding 24 C Fatty Acyl-CoA and 24 C Fatty Alcohol to the expressed product,and HPLC showed the ester was produced.Our study results confirmed that,the ws gene we identified was the key enzyme gene invoved in wax biosynthesis.The results were important to unclose the molecular mechanism of white wax secretion.