SSR Molecular Marker Screening And Linkage Location Analysis Of Mutant Tub Gene In Silk Worm

The research on silkworm experimental genetic map has last for nearly 100 years, and more than 300 mutant characters have been located in 230 loci including many important biochemistry traits. There are more than 600 silk worm mutations breeds in the gene pool bank of the Southweast University, which contains many traits concerning to production, genetical breeding and vital function. Once found find the DNA molecular markers Hnkaged to these traits, we can probably locate the mutations on chromosomes and further clone them; Meanwhile, this will help to marker-assisted selection of silk worm. The construction of genetic map connects the basic theory and practical application, can also provide fundation to researches of silk worm resource,breeding and molecular clone. Genetic maps of RFLP, RAPD, AFLP, SSR and classical linkage map of silk worm have been punlished, in which the integration of molecular map and classical map is the hot point on research.In this research, we analysed the near isofenic lines of silk worm using SSR primers, and picked out SSR molecular markers linkaged to marker genes in corresponsive linked groups. In this way, a technic system of location of function genes can be established, and provide fundation to many concerning research, such as gene clone, analysis of relationship, variety identification, genetic improvement, resource protection and marker-assisted selection. The main results as follows:(1). Screening of SSR molecular markers: Using SSR-PCR technology, We analysed 6 linked groups of near isofenic lines and back cross parent dczao, and picked out 27 of 329 pairs SSR primers which expose polymorpahy in near isofenic lines.In these primers, 10 and 12 linkaged to q gene in 7th linked group and cts gene in 16th linked group.1 to p~s gene in 2th linked group ,1 to L gene in 4th linked group and 1 to tub gene in 23th linked group.(2). Testify of SSR molecular markers: Corresponsively ues near isofenic lines to testify the 27 pairs of SSR primers,this means by parent individual, sequencing, systemic and hybridization test..At first,3 times repeats test of these SSR molecular markers can get the same stable result,which demonstrate the small experimental error.Then in the test of each parent individual,the linked groups had some distinctions in a certain degree,except 23th linked group of near isofenic lines.The reason may be the remaind distinctions in near isofenic lines individual.Next,secquenced the special fragment of tub gene in 23th linked group and found a AC repeats microsatellite secquence.In addition,used SSR markert PSSRF03 to systemic test,result was that the band type of tub traited- individual was similar to that of near isofenic lines parent.This result indicated that the SSR marker in 23th linked group is linkaged to tub gene.Finally.the hybridization of F1 generation and parent near isofenic lines indicated that SSR marker PSSRF03 tightly linkaged to tub gene in 23th linked group.(3). Linkage locational analysis of mutant tub gene in 23th linked group:The SSR analysis on BC1 generation of 23th near isofenic lines and C108 strain by SSR marker PSSRF03 showed that 149 individuals among 309 appear tub trait including 12 individuals with single exchange,the other 162...