An Analysis on Differential Protein Expression in Embryonic Stage of Bivoltine Bombyx mori Eggs Incubated Under Low and Normal Temperatures

The diapause of bivoltine silkworm (Bombyx mori) eggs is controlled by environmental conditions at the embryonic stage of their parental generation. Studies on diapause associated proteins at the embryonic stage would provide experimental evidence for ultimate elucidation of the molecular mechanism of silkworm diapause. In present study,silkworm eggs of a bivoltine variety Qiufeng were incubated under 25 ℃ and 18 ℃ respectively,and both soluble and insoluble proteins were prepared from the eggs at different embryonic stages. Two-dimensional electrophoresis (2-DE) and image analysis system were employed to investigate differential protein expression profiles of eggs at different embryonic stages. From the soluble and insoluble protein profiles,5 and 7 differential protein spots were detected respectively,in which 8 spots were identified by mass spectrometry as the credible best-matched proteins including egg specific protein,vitellogenin,putative cuticle protein, and pyruvate dehydrogenase kinase. These differential proteins are likely to cause variation of substance and energy metabolism in silkworm embryos. It is therefore presumed that low and normal temperature incubations might induce different physiological and biochemical responses in silkworm eggs.