驱动蛋白及其类似蛋白在哺乳动物卵母细胞减数分裂同源染色体配对中的功能及调节研究

The pairing of homologous chromosomes is a unique event in early prophase of meiosis, it ensures the stability of chromosome inheritance, as well as creates diversity of genome heredity through proper homologous recombination thereafter. Abnormal pairing could cause aneuploidy and infertile gametes at really high frequency. How could initially randomly dispersed homologous chromosomes accurately move together and pair? Many molecules are known to be involved in pairing, but none of them could be the origin of force driving chromosome movement. Kinesin is a super protein family with ATPase activity, many of subfamily members can drive chromosome movement directly or indirectly through chromosome-connected microtubules. So could kinesin also be the original engine driving homologous chromosome movement? In current project, using mouse oocytes as major material and 4-D live imaging as core technique, on the one hand we will study whether those known kinesins are the original driving forces for homologous chromosome movement, on the other hand in combination of several strategies and mainly by differential expression chips and mass-spec, we will thoroughly screen new kinesin-like proteins and characterize their function and regulation in homologous pairing. The fulfillment of this projects will significantly promote the related basic studies, thus make important contribution to the studies of human reproductive health and remedies against reproductive disease.

)：同源染色体配对是减数分裂早前期的特有事件，它既保证了染色体遗传的稳定性，配对后的适宜重组又保证了基因组遗传的多样性。而配对异常会导致极高比例的非整倍体及不育配子。同源染色体从起始时散在于细胞核中到精确移动到一起并配对，其机理是什么？已知有许多配对相关分子，但没有一种能提供染色体移动的动力来源。驱动蛋白是具有ATP 酶活性的蛋白超家族，其中多个亚家族成员可以直接或通过相连的微管间接推动有丝分裂染色体的移动。驱动蛋白是否也是减数分裂同源染色体移动的动力引擎？本研究拟以小鼠卵母细胞为实验材料，以四维活细胞电影为核心技术，一方面探究已知驱动蛋白是否是推动配对的原动力，另一方面通过多种策略用差异表达芯片和质谱来全面筛选新型驱动蛋白类似蛋白并鉴定其在同源配对中的作用及功能调节。该计划的顺利实施和完成将显著促进相关基础研究并为人类生殖健康和生殖系统疾病防治做出贡献。

本项目的原本研究目标是鉴定驱动蛋白是否在减数分裂前期同源染色体配对发挥其“动力引擎”作用、其功能如何调节及不同驱动蛋白如何协同在配对中发挥作用。研究的核心技术是四维动态电影。但我们发现对减数分裂同源染色体进行动态电影观察有两个技术瓶颈，所以在第二、三年我们在进展书中申请将研究重心转移，一方面在卵母细胞中开发不依赖于显微注射的基因敲降技术，为下一步在原始卵泡中开发类似技术打下基础；另一方面研究ZP3和pnma5在减数分裂起始生发泡破裂、减数分裂及受精过程中的功能及调节，为此后研究驱动蛋白在减数分裂同源染色体配对中的功能及调节奠定基础。经过4年研究，一方面我们已在世界上首次成功开发了在卵母细胞上用新型多肽纳米颗粒N-ter（Sigma公司）介导的siRNA转染的基因敲降技术及用新型多肽纳米颗粒Chariot（Active motif公司）介导的抗体转染的蛋白抑制技术。另一方面我们鉴定了ZP3和pnma5在减数分裂起始生发泡破裂、减数分裂及受精过程中的重要功能及调节机制。通过本基金的支持已发表三篇sci论文，正处在评审阶段的论文一篇。通过这些成果在技术平台和机制两方面促进了卵母细胞减数分裂的研究。