Ligase Ⅳ基因突变对小鼠生长及成体神经系统发育的影响

Effect of Ligase Ⅳ gene mutation on growth and nervous system development in mice

摘要:

目的 研究Ligase Ⅳ对小鼠生长及成体神经系统发育的影响。方法 记录野生型（WT）和突变型Ligase ⅣY288C纯合子（MU）小鼠的生存情况，绘制小鼠生存曲线；记录小鼠不同生长时期的体质量和脑质量，监测小鼠个体发育和脑发育差异；用Sox2和Nestin免疫染色来检测小鼠侧脑室下区（subventricular zone， SVZ）神经干细胞（neural stem cells， NSCs）的数量；用Ki67和Nestin免疫染色来检测小鼠SVZ的NSCs增殖情况；原代分离培养小鼠SVZ的NSCs，用克隆形成实验检测细胞的生长状况。结果 MU小鼠的平均寿命明显低于WT小鼠（P＜0.0001）；MU小鼠的体质量和脑质量在生长的各个时期均明显小于WT小鼠（P＜0.0001）；MU小鼠大脑SVZ的NSCs数量及增殖细胞数均比WT少（P＜0.0113）；MU小鼠NSCs的克隆形成能力低于WT小鼠（P＜0.001）。结论 Ligase Ⅳ突变在小鼠生长及成体神经系统发育的过程中起重要作用。

Abstract:

Objective To investigate the effect of Ligase Ⅳ on the growth and nervous system development in mice. Methods The growth of wild-type(WT) and mutant Ligase ⅣY288C homozygous(MU) mice was recorded, and the survival analysis was performed with GraphPad. The body and brain weight at different ages of mice were measured. The expression of Sox2 and Nestin was detected by immunoflurescent staining to count the number of neural stem cells(NSCs) in the subventricular zone(SVZ) of mice brain; and the expression of Ki67 and Nestin was detected to examine the proliferation of NSCs in SVZ of mice. Primary culture of NSCs in SVZ of mice was performed and the cell growth was tested by cloning formation assay. Results The average life span of MU mice was significantly lower than that of WT mice（P <0.0001）. The body weight and the brain weight of MU mice were significantly lower than those of WT mice at all ages（P<0.0001）. The numbers of NSCs and proliferating cells in SVZ region of MU mice were less than those of WT mice（P<0.0113）, and the colony forming ability of NSCs in MU mice was lower than that in WT mice（P<0.001）. Conclusion Ligase Ⅳ may play an important role in the growth and the development of the nervous system of mice.