生长休止蛋白7在大鼠小脑皮质发育过程中的动态表达

Expression of growth arrest-specific protein 7 in the cerebellar cortex of rats during development

目的研究生长休止蛋白7(Gas7)在大鼠小脑皮质不同发育时期的动态表达。方法采用逆转录聚合酶链反应(RT-PCR)方法检测Gas7mRNA在大鼠小脑皮质不同发育时期的表达;免疫组织化学方法观察Gas7蛋白在大鼠小脑皮质不同发育时期的表达和分布。结果 RT-PCR结果:Gas7mRNA在大鼠小脑皮质发育时期的表达呈现先增强后减弱的趋势,高峰出现在生后第21d(P21)。免疫组化实验结果:在胚胎第18.5d(E18.5)和E20.5仅Purkinje细胞层有Gas7免疫阳性产物分布;出生当天(P0)外颗粒层出现Gas7阳性神经纤维,Purkinje细胞层出现形态不规则的Gas7免疫阳性细胞;P7外颗粒层和Purkinje细胞层免疫反应增强,内颗粒层出现一些散在的Gas7强阳性细胞,胞体较小,突起清晰可见;P14小脑皮质4层均有Gas7阳性表达;P21小脑皮质3层Gas7免疫阳性反应较P14增强(P<0.01);Adult(2月龄)较P21免疫反应减弱(P<0.01)。结论 Gas7在大鼠小脑皮质发育过程中的动态表达呈现出时空特异性,提示Gas7基因在大鼠小脑皮质发育过程中可能起着重要的调控作用。

Objective To observe the expression of growth arrest-specific protein 7(Gas7)in the cerebellar cortex of rats at different developmental stages.Methods We used RT-PCR to detect the expression of Gas7 mRNA and immunohistochemical method to study the expression of Gas7 protein in the cerebellar cortex at different develop-pmental stages.Results The expression of Gas7 mRNA in the cerebellar cortex of rats gradually increased and then decreased,with the peak in postnatal day 21(P21).Immunohistochemistry showed that at embryonic day 18.5(E18.5)and E20.5,Gas7 positive products were only observed in Purkinje cell layer;at P0,Gas7 positive nerve fibers first appeared in the external granular layer,while in Purkinje cell layer irregular Gas7 positive cells were observed;at P7,the staining enhanced in the external granular layer and Purkinje cell layer,while in internal granular layer,sparse strong staining Gas7 immunoreactive cells were observed,the cell body was small,and the process was clear;at P14,Gas7 positive products were observed in all four layers;at P21,the staining in three layers was stronger than that of P14(P<0.01);in adulthood,the staining was weaker than that of P14(P<0.01).Conclusion The expression of Gas7 in the cerebellar cortex of rats shows both position and time dependency,suggesting that the Gas7 gene may play an important role in the cerebellar cortex of rats during development.