Study On The Relationship Between The Cocoon Characters And The Protein Expression Patterns In Bombyx Mori Breeds

As the final products of most genes,proteins are the functional units in the hierarchical regulation cascade of genes.The proteomics research in silkworm has been gradually become one important post-genome focus after the functional genomic research era.To explore the protein expression differences between the improved Jinqiu and its breeds,the differences of the protein expression patterns were analyzed among them to study the gene construction and the base for illuminating the mechanisms of better cross breeding in silkworms. Protein samples from hemolymph,silk gland and midgut were separated by the technology of proteome.We found that the matched proteins between Jinqiu and its breeds were both about 70%in the three kinds of tissue,but the other 30%proteins were special to each other, respectively.9%-24%proteins in the matched parts were up-regulated or down-regulated expression.These special proteins would be the new proteins which came from the genic interaction of the two parents' genes in the cross breeding or the modified proteins which came from the different modifications of the same original proteins.It was indicated that a better new breed by cross breeding could be depend on the actions of some new function proteins from genic interaction in addition to marshaling genes from crossing breeds.To verify the molecular regulating basis of the characters of cocoon shell weight,the posterior silk gland cells and hemolymph from three breeds which had almost the same heredity background and the characters of cocooning normal,thin shell and no-shell cocoon(naked pupa) were used as experimental materials to analyze the relationship between their protein expression patterns and cocoon shell weight by two-dimensional gel electrophoresis and image analysis. Results showed that the percent of matched protein spots between the naked pupa breed and the normal cocooning breed was about 65%and the other 35%protein spots were special ones respectively.It suggested that the character of naked pupa was probably controlled by the major genes with some minor genes in heredity.Results also showed the isoelectric point difference of the posterior silk gland cells among the three breeds was more obvious than that of the hemolymph,which could suggest that the major effects on the cocoon shell weight came from silk gland proteins other than the hemolymph.The special protein spots and the up-regulated or down-regulated proteins in the three breeds were likely to subsist the proteins related to the biological characters of the cocoon shell weight of more,less and none,respectively.