高、低温催青诱导家蚕滞育发生中的蛋白质修饰

Protein modification in the diapause occurrence of Bombyx mori induced by high or low temperature incubation

【目的】研究高、低温诱导家蚕Bombyx mori滞育发生时蚕卵蛋白质修饰的差异,为后续深入探究昆虫滞育诱导的分子机制提供参考。【方法】饲养二化性家蚕品种,筛选出稳定的受高、低温诱导滞育发生的家蚕品系。以此为材料,分别于25和15℃孵化蚕卵,敏感期和点青期取样进行表观遗传学研究,通过SDS-PAGE电泳和Western blot检测蛋白修饰的差异。【结果】高温(25℃)组蚕卵蛋白的甲基化修饰水平始终高于低温(15℃)组,点青期有显著差异;高、低温处理组之间的乙酰化修饰水平一直差异显著,在点青期高温组显著低于低温组;低温组的泛素化修饰水平始终高于高温组,尤其是发育前期;磷酸化修饰水平整体较高,但高、低温处理组之间差异不显著;丙二酰化在高、低温处理组之间没有明显差异;琥珀酰化的修饰水平始终较低,在发育后期有明显的差异修饰蛋白出现。【结论】蚕卵在25℃催青过程中蛋白质泛素化和乙酰化修饰水平与15℃低温组在全时期都存在显著差异,甲基化修饰水平在点青期存在显著差异,表明甲基化、泛素化和乙酰化修饰在家蚕早期滞育诱导过程中起作用。

【Objective】To study the difference of protein modification of silkworm(Bombyx mori)eggs during diapause induced by high or low temperature,and provide references for further exploration of molecular mechanism of insect diapause induction.【Method】The stable diapause silkworm strains induced by high or low temperature were screened out by raising the bivoltine silkworm varieties.Using the selected strains as materials,the eggs were incubated at 25 and 15℃respectively.Samples were taken at the sensitive stage and the head pigmentation phase for epigenetic studies.The differences of protein modification were detected by SDS-PAGE electrophoresis and Western blot.【Result】The methylation level of protein in silkworm eggs in high temperature(25℃)group was always higher than that of low temperature(15℃)group,and there was significant difference at the head pigmentation phase.The levels of acetylation modification had always been significantly different between high and low temperature groups,and the high temperature group had significantly lower level compared with the low temperature group at the head pigmentation phase.The ubiquitination level of the low temperature group was always higher than that of the high temperature group,especially in the early stage of development.The levels of phosphorylation modification of both groups were high overall,and there was no significant difference between high and low temperature groups.The malonylation levels of protein in silkworm eggs did not change significantly between high and low temperature groups.The levels of succinylation modification of high and low temperature groups were always low,and there were obvious differential modification proteins in late developmental stage.【Conclusion】There are significant differences in the protein ubiquitination and acetylation modification level of silkworm eggs incubated at 25℃compared with those at 15℃throughout development,and the levels of methylation are significantly different at the head pigmentation phase,suggesting that methylation,ubiquitination and acetylation play important roles in early diapause induction process of silkworm.