Analysis On The Gonads Protein Of Both Sexs By Two Dimensional Electrophoresis And Mapping Of The+~P Gene Using SSR Marker In Silkworm, Bombyx Mori

Silkworm larvae possess markings with various categories and are easy toidentify, which is hence considered an extremely useful source for research in genetics.Using mutation means to translocate chromosome fragment containing normalmarking gene to W chromosome, the normal marking trait occurred on the femaleonly, to create a marking sex-limited silkworm variety. The character of nomalmarking is controlled by+~Pgene which was mapped at0.0cM of the silkwormclassical genetic linkage group2.In this paper, with the marking sex-limited silkworm strain H9, the highresolution two-dimensional polyacrylamide gel eletrophoresis (2-DE) and computerassisted image analysis were used to screen the protein pattern of the female and malesilkworm gonads and quantitativly analyze the diference in their proteinexpressions．We compared the proteins in the male and female gonads of silkworm onthe4th day and6th day of the five instar larva stage and the2nd day of the pupalstage．More than100protein spots were observed in all the six samples, in whichsome specific protein spots may be related to the formation of+~Pmarking and theunknown gene products in the translocated segments to W chromosome. The matchpercentages of gonads from different stages were all around75％, was maximum atthe4th day of the five star larva stage and minimum at the2nd day of pupal stage.This may be related to the exuberant differentiation of the goands at the importantabnormal developmental stages.Owning to a lack of crossing over in females, silkworm strain p50of which larvahas normal marking and H9of which larva has sex-limited marking were used toprepare reciprocal populations (H9×p50)×H9and H9×(H9×p50)，designated asBC1F and BC1M．Based on the2th linkage group of already established silkwormSSR molecular marker linkage map，15pairs of SSR marker primers were used formapping and linkage analysis of the+~Pgene. Three SSR primers linked to+~Pgenewas selected. The reciprocal population BC1M was utilized construct a geneticlinkage map containing silkworm+~Pgene and its linked SSR markers． The obtainedlinkage map has a genetic distance of22.5cM, and+~Pgene is located at11.3cM. Themarker closest to+~Pis S0206，with a genetic distance of3.0cM．Based on finegenome map of domesticated silkworm (B. mori), the result of Kaikoblast show thatBGIBMGA009689, BGIBMGA009688and BGIBMGA009687are closer to+~P, and the BGIBMGA009689is nearest to+~P, which physical distance is19.1Kb.The above results will not only contribute to investigate the functional proteinsrelated to sexual trait, but also help exploring the regulating mechanism of relatedgenes during the development of gonad, and have the important meaning to theprecise mapping of+~Pgene and the sex-limited marking assisted breeding ofmolecular markers.