卵母细胞老化所致非整倍体形成中BACH1的调控作用

Aneuploidy is thought to be the main reason for the high miscarriage and low pregnancy rates of aging female. Aneuploidy always arises from non-disjunction of chromosomes during mitosis or meiosis. But the mechanisms of abnormal chromosomes non-disjunction in meiosis of aging oocytes are not so clear by now. BACH1/FANCJ (BRCA1-associated C-terminal helicase 1, or Fanconi Anemia J) is one of the Fanconi Anemia proteins, which is resolved in the DNA interstrand crosslinking repair. However, there are still no reports about the functions of BACH 1 in meiosis of oocytes by our knowledge. Our previous researches revealed that BACH1 also regulate mitosis via centrosome cycle. And the expression of BACH1 is decreased in aging oocytes. Thus, our hypothesis is that the decrease of BACH1 in aging oocytes will activate SAC and regulate meiotic spindle assembly, which will induce the increased aneuploidy during meiosis. We are planning experiments to reveal regulative functions of BACH1 for meiotic SAC and mechanisms of aneuploidy formation in oocyte meiosis via siRNA, immunostaining and so on. In this project, we hope to clarify the details of BACH 1 in aging-reduced aneuploidy in oocytes, which will undoubtedly provide powerful theoretical basis for the improving of the fertility of aging females.

胚胎非整倍体发生率增加，是引起高龄女性低妊娠率和高流产率的重要原因。非整倍体主要因细胞分裂时染色体分离异常产生，但其在老化的卵母细胞减数分裂过程中的发生机制并不明了。BACH1/FANCJ (BRCA1-associated C-terminal helicase 1 / Fanconi Anemia J) 是范科尼贫血蛋白家族成员之一，主要参与DNA交联损伤修复途径，但对卵母细胞减数分裂的调控作用目前未见报道。我们已证实BACH1通过调节中心体循环参与有丝分裂调控，并发现其在老龄卵母细胞中的表达减少。由此我们提出假说：老化的卵母细胞中BACH1表达减少，激活纺锤体组装检查点，影响减数分裂纺锤体组装，导致细胞分裂时非整倍体形成。本研究拟用siRNA等方法，探讨BACH1对减数分裂SAC及其下游相关因子的调节作用，揭示老化的卵母细胞中非整倍体的发生机制,为提高高龄女性生殖能力提供理论依据。

胚胎非整倍体发生率增加，是引起高龄女性低妊娠率和高流产率的重要原因。非整倍体主要因细胞分裂时染色体分离异常产生，但其在老化的卵母细胞减数分裂过程中的发生机制并不明了。BACH1/FANCJ (BRCA1-associated C-terminal helicase 1 / Fanconi AnemiaJ) 是范科尼贫血蛋白家族成员之一，主要参与DNA交联损伤修复途径，但对卵母细胞减数分裂的调控作用目前未见报道。我们已证实BACH1通过调节中心体循环参与有丝分裂调控，并发现其在老龄卵母细胞中的表达减少。本研究中，我们以不同年龄阶段小鼠卵母细胞为研究对象，通过卵巢刺激促排卵、卵母细胞体外培养，运用染色体形态分析、免疫荧光染色、Western Blot、qPCR等方法，分析不同年龄小鼠中染色体形态，BRCA1、BACH1以及纺锤体组装检查点相关蛋白Aurora、PLK1、MAD等在不同时期卵母细胞中的定位及表达差异，并在青年期卵母细胞中应用BACH1抑制剂Phen-DC3，用以验证BACH1下调状态下所致的纺锤体形态异常及相关SAC蛋白表达异常，从而证实我们的假说，即老化的卵母细胞中BACH1表达减少，激活纺锤体组装检查点，影响减数分裂纺锤体组装，导致细胞分裂时非整倍体形成。本研究进一步探讨了BACH1对减数分裂SAC及其下游相关因子的调节作用，揭示老化的卵母细胞中非整倍体的发生机制,为提高高龄女性生殖能力提供理论依据。