Functional analysis of Cdk5 by using conditional KO of its activating subunit p35

本研究的目的是通过空间学习、恐惧条件反射测试、电生理分析和生化分析等行为分析，以条件性KO小鼠p35为研究对象，分析神经元特异性丝氨酸/苏氨酸激酶细胞周期蛋白依赖性激酶5(CDK5)的功能。在这项研究中，我们产生了p35-FLOX小鼠，其中两个loxP序列插入了p35基因等位基因。我们用三苯氧胺(Tamoxifen，TM)激活Cre并在脑形成后破坏p35基因的Creer小鼠和p35-Flox小鼠杂交，获得了可诱导的p35条件性KO。我们证实，连续三天口服2 mg TM可减少p35蛋白。我们还通过与CaMKII-Cre小鼠杂交获得了CA1特异性p35条件性KO小鼠，并证实了p35蛋白在海马区的表达水平降低。我们观察到CA1-p35 CKO小鼠海马区CA1区锥体神经元中树突棘的数量减少。利用这些p35条件性KO小鼠，我们目前对p35 CKO小鼠进行了行为分析。

The purpose of this study is to analyze the function of neuron-specific serine/threonine kinase Cyclin-dependent kinase 5(Cdk5) by using conditional KO mice of its activating subunit p35 trough the behavioral analysis such as spatial learning and fear conditioning test, and electrophysiological analysis and biochemical analysis. In this study we generated p35-flox mice in which two loxP sequences were inserted in p35 gene allele. We generated inducible p35 conditional KO by crossing p35-flox and CreER mice in which Cre is activated by Tamoxifen(TM) and p35 gene was destructed after brain formed. We confirmed decrease of p35 protein by p. o. administration of 2 mg TM for three days. We also generated CA1-specific p35 conditional KO mice by crossing CaMKII-Cre mice, and confirmed decreased level of p35 protein in hippocampus. We observed decreased numbers of dendritic spines in the hippocampal CA1 pyramidal neurons in CA1-p35 cKO mice. Using these p35 conditional KO mice, we currently conduct behavioral analysis of p35 cKO mice.