发育中Wistar大鼠大脑皮层甲基化结合蛋白-2基因表达变化

Expression of mythl-CpG-binding protein-2 gene in developing rat brain

目的 :研究甲基化结合蛋白 2 (methyl CpG bindingprotein 2 ,mecp2 )基因在发育中正常Wistar大鼠大脑皮层表达水平的变化。方法 :应用实时定量PCR(real timePCR) ,Northern印迹杂交对mecp2基因在正常Wistar大鼠发育的不同阶段 :胚胎第 1 5天 (E1 5 )、第 1 7天 (E1 7)、第 1 9天 (E1 9)、出生当日 (P0 ) ,生后第 7天 (P7)、生后第 1 4天 (P1 4 )、生后第 2 8天 (P2 8) ,成年期大鼠mRNA的表达水平进行定性、定量分析 ;应用Western印迹杂交对MeCP2的表达水平进行半定量分析。结果 :mecp2基因是在正常Wistar大鼠大脑皮层中表达的mRNA ,约为 1 0kb。从胚胎至成年期的发育过程中 ,mecp2基因mRNA的表达虽有波动 ,但差异无显著性。mecp2基因在正常Wistar大鼠大脑皮层中仅表达一种MeCP2 ,相对分子质量为 75 0 0 0。在不同发育阶段其表达水平表现为 ,胚胎E1 5表达水平最低 ,自胚胎E1 9始至成年期MeCP2表达水平较E1 5明显增高。生后第 7日至成年期 ,各时间点间表达水平的变化差异没有显著性。结论 :随着正常Wistar大鼠大脑皮层神经元的发育成熟 ,MeCP2的表达水平逐渐增高 ,说明MeCP2对神经元的成熟有重要作用 。

Objective: To analyze the expression of mecp2 gene at mRNA and protein;Cerebral cortex level in the cerebral cortex of the normal Wistar rat throughout development. Methods: We chose the 15th day (E15), 17th day (E17), 19th day (E19) of embryo period, the day of birth (P0), the 7th day (P7), the 14th day (P14), the 28th day (P28) of postnatal period, and adulthood as analyzing time points. The expression of mecp2 gene at mRNA level was analyzed by real time PCR and Northern blot. The expression of MeCP2 protein was analyzed by Western blot. Results: There was one type of mecp2 mRNA transcript (approximately 10 kb) expressed in the cerebral cortex of the normal Wistar rat. The expression level of mecp2 mRNA varied subtly during the development. There was one type of MeCP2 protein (75 000) expressed in the cerebral cortex of the normal Wistar rat. The expression level of MeCP2 protein remained the lowest on E15, from E19 to adulthood the expression levels of MeCP2 protein increased dramatically compared with that on E15. From P7 to adulthood, the differences of expression between two time points were subtle. Conclusion: The expression level of MeCP2 protein increases as the neurons in the cerebral cortex of normal Wistar rat grow mature. This indicates that MeCP2 protein is very important to neuron's maturation, and probably has relationship with maintaining maturation state of neurons.