Cloning,Expression And Function Analysis Of Sex Determination Gene Bodsx Of Bradysia Odoriphaga

Bradysia odoriphaga is one of the major pests on the Liliaceous vegetables such as Chinese chive and it can reduce its production greatly.The Doublesex(dsx)gene is a key gene of sex differentiation in insects.Sex determination and differentiation are key factors affecting the reproduction,development and population structure of B.odoriphaga,however,the molecular mechanism of sex determination of B.odoriphaga has not been reported so far.Partial sequence of Bodsx was obtained from transcriptome database.RT-PCR and RACE methods were used to obtain the Bodsx gene.The prediction of conserved domains,multiple alignments of amino acid sequences and phylogenetic analysis were conducted using bioinformatics software.The expression profiles of Bodsx in different developmental stages were performed by qPCR,and RNAi technology was used to explore the function of dsx gene in sex determination of B.odoriphaga.Major research results are as follows:1.Four different splice variants were obtained from Bodsx gene,of which two sequences were present in both males and females.The other two predicted BoDSX proteins are female specific protein BoDSXF and male specific protein BoDSXM,respectively.There were conserved OD1 and OD2 domains in BoDSX,which play roles in DNA-protein interactions.Conserved domain of Dipteran dsx can also be found in our sequences,such as RBP1 target sequences,ISS and Nasonia/Apis repeat element.2.Quantitative analysis showed that dsx gene of B.odoriphaga was expressed from egg stage,and it was up-regulated at third-instar larvae.Finally,it reached the highest level in adult stages and the expression levels of male adults were significantly higher than female.3.The effects of silencing Bodsx gene during the development of B.odoriphaga were explored.Bodsx silencing could result in the decrease of body length and gonst length of male.It may affect mating ability of males after silencing.Bodsx showed conserved structure and expression profiles.RNAi technology verified the function of dsx gene in the sex determination of B.odoriphaga.Our results will be helpful to understand the molecular mechanism of sex determination of B.odoriphaga and it will be an effective method to control B.odoriphaga.