Initial Study On Gene Mutation And Artificial Selection From Bombyx Mandarina To Bombyx Mori

The core of the evolution research is to describe the evolution history of the species and discover the mechanism of the process of evolution. Since the middle of this century, Molecular Biology developed fast, and the research of evolution has upgraded into the molecular level. On one side, the molecular research studies the origin of the lives; on the other side, it studies the synthesis mechanism of the natural chemical, to explain how the species' phenotype and traits changed via the changes of the DNA, RNA, protein and carbohydrate, and set up a series of theories and methods based on sequence information of nucleotides and proteins.In the last decade, the genome sequences developed quickly, so are the research methods of genomics. They provide necessary conditions for evolution research, and also, fasten the development of the new interdisciplinary of genomics. One of the important research fields of evolution genomics is the evolution genomics.The bloods relationship of the silkworm and wild silkworm is on intimate terms. As an abundant wild sericultural resource, wild silkworm is a treasure with much potential to exploit and also be used as an important material for the evolution on the origin of silkworm. These years, with the development of molecular biology, the evolution research related to Bombyx mandarina and Bombyx Mori has got much progress; however, most of the results are focused on Molecular Systematics. Few reports are related to artificial selection. So, in this investigation, based on the genome data of Bombyx mori and the EST data of Bombyx mandarina, we did some comparison and analyse.We selected 343 orthologs from the genome of Bombyx mori and EST of Bombyx mandaina. In order to do comparable analysis, we also select 1328 orthologs from Drosophila melanogaster and Drosophila simulans. Via genomics analysis, we found the value of Ka/Ks of bombyx is higher than drosophila, and the difference is significant. No matter caring about the median or the distribution, the data always tells the same thing. We consider it should due to the intensively artificial selection, which lead to the fast evolution speed of the Bombyx..Refer to the expression level, we studied the genes expressing specifically in one tissue. We found that the genes expressing specifically in the silk grand have much higher Ka/Ks. It may due to the artificial selection on the silk excreting by bombyx which made the genes expressing specifically in silk grand suffered a greater selection pressure. As a result, these genes have a higher evolution speed.