二化性家蚕卵低温和常温催青的胚胎期蛋白质表达差异分析

家蚕二化性品种的滞育性受上代胚胎期环境条件调控,查找家蚕胚胎期滞育关联蛋白,可为最终阐明家蚕滞育的分子机制提供实验依据。以家蚕二化性品种秋丰的蚕卵为材料,分别在25℃常温和18℃低温条件下催青,提取胚胎不同发育时期蚕卵的易溶性和难溶性蛋白,采用蛋白质双向电泳(2-DE)和图像分析技术,研究蚕卵在胚胎不同发育时期的蛋白质差异表达谱。在易溶性和难溶性蛋白图谱中分别检测到5个和7个差异显著的蛋白点。对这些差异蛋白点进行质谱鉴定,有8个蛋白点得到可信的最佳匹配蛋白报告,共鉴定出卵特异蛋白、卵黄原蛋白、表皮蛋白和丙酮酸脱氢酶激酶4种蛋白。这些差异表达蛋白可能导致蚕卵胚胎中物质代谢和能量代谢的不同,据此推测低温和常温催青可能在蚕卵胚胎中诱导了不同的生理生化反应。

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.