Studies On The Proteome Of Yolk And Embryo Of Silkworm(Bombyx Mori)During Incubation Stages

Embryo development is one of the most important subjects in life science research. Silkworm, a typical model system, developing from a fertilized egg to a cellulous individual, is the result of various genes temporally and spatially expressed sequentially. Silkworm is differentiated to head, chest,belly and other various organs and tissues of larva according to pre-arranged distracts during incubation stage, but the function of these genes that induced these changes in morphological characters are still not fully understood. In post-genome period, the functional genome will become the main field of research, and the proteome research is the most important method to exploit gene function. Currently, the mechanism of the silkworm embryo development is still under research, and it is necessary to initiate the proteome research about silkworm embryo during incubation stage.In this research, immobilized pH gradient 2-D polyacrylmide gel electrophoresis, mass spectrometry and protein database system were adopted to study silkworm embryo functional protein during incubation stages, In order to discover the components of yolk protein in the mature egg and the metabolism with embryo development during the incubation stages, we had established the 2-DE patterns of embryo protein during different incubation stages, analyzed the special differential expressed protein spots between different embryos, and clarified the function of some concerned proteins.Initial Research was focused on the components of yolk protein in matured eggs in present research, and main changes of yolk protein during incubation stages were found in molecular level.Through the comparative analysis of the 2-DE patterns of yolk protein in matured egg of silkworm, about 200 protein spots were detected in the gel (previous research reported there were three types of yolk protein). Three types of abundant proteins, including vitellin, 30kD protein andEgg specific protein(ESP), were observed to accounted for 65.5% of the total yolk protein, and many protein spots were detected in the area marked as 30 kD?which could be due to the existence of extremely similar multigene family of 30kD protein. In the corresponding domain for 42kD protein of vitellin, 10 high level proteins linked together, which might be caused by different protein post processing or sample modulation, or the existence of extremely similar multigene family in the silkworm. Comparison study was carried out on the yolk protein patterns from unmated silkworm eggs of multivoltine variety P50 and biovoltine variety Feng-1. After 2-DE electrohporesis and silver staining of yolk protein from unmated silkworm eggs of P50 and Feng-1, the detected protein spots were, 203 and 185 respectively while the matching rate of protein spots was 77.84%. Moreover, the content of three types of abundant protein, namely, vitellin, 30kD protein and ESP, were different in this two varieties. The diversity of yolk protein existence in different varieties suggested that the concentration and type of yolk protein might be related to the factors such as voltinism and moltinism of the species, or geographical distribution and etc.The changes of yolk protein in different development stages were also discussed in the present research.. Through 2-DE electrophoresis and sliver staining of the variety P50 at end reversal stage of embryo, about 197 protein spots were detected. Through the match analysis of the 2-DE protein patterns of yolk protein between unmated silkworm eggs from P50 at end reversal stage in embryo, the matching rate of these two patterns reached 93%, which suggested that there was no change of yolk protein from the same variety during embryo development. The content of three abundant protein, namely, vitellin, 30kD protein and ESP, is no great change and most of the matched protein spots are also very close in concentration. These results indicated that, through constant basis analysis of yolk protein, the type and content of yolk protein during different embryo development stages are stable. In oth...