The Key Laboratory of National Education Ministry for Mammalian Reproductive Biology and Biotechnology, Inner Mongolia University, Hohhot, Inner Mongolia, People's Republic of China.
PLoS One. 2013 May 15;8(5):e63173. doi: 10.1371/journal.pone.0063173. Print 2013.
Casein kinase I alpha (CK1α) is a member of serine/threonine protein kinase, generally present in all eukaryotes. In mammals, CK1α regulates the transition from interphase to metaphase in mitosis. However, little is known about its role in meiosis. Here we examined Ck1α mRNA and protein expression, as well as its subcellular localization in mouse oocytes from germinal vesicle to the late 1-cell stage. Our results showed that the expression level of CK1α was increased in metaphase. Immunostaining results showed that CK1α colocalized with condensed chromosomes during oocyte meiotic maturation and early embryo development. We used the loss-of-function approach by employing CK1α specific morpholino injection to block the function of CK1α. This functional blocking leads to failure of polar body 1 (PB1) extrusion, chromosome misalignment and MII plate incrassation. We further found that D4476, a specific and efficient CK1 inhibitor, decreased the rate of PB1 extrusion. Moreover, D4476 resulted in giant polar body extrusion, oocyte pro-MI arrest, chromosome congression failure and impairment of embryo developmental potential. In addition, we employed pyrvinium pamoate (PP), an allosteric activator of CK1α, to enhance CK1α activity in oocytes. Supplementation of PP induced oocyte meiotic maturation failure, severe congression abnormalities and misalignment of chromosomes. Taken together, our study for the first time demonstrates that CK1α is required for chromosome alignment and segregation during oocyte meiotic maturation and early embryo development.
酪蛋白激酶 Iα（CK1α）是丝氨酸/苏氨酸蛋白激酶的成员，普遍存在于所有真核生物中。在哺乳动物中，CK1α 调节有丝分裂中从间期到中期的转变。然而，其在减数分裂中的作用知之甚少。在这里，我们研究了从生发泡期到晚期 1 细胞期的小鼠卵母细胞中 Ck1α mRNA 和蛋白表达及其亚细胞定位。我们的结果表明，CK1α 的表达水平在中期增加。免疫染色结果表明，CK1α 在卵母细胞减数成熟和早期胚胎发育过程中与浓缩的染色体共定位。我们使用 CK1α 特异性的 morpholino 注射来阻断 CK1α 的功能，从而采用了功能丧失的方法。这种功能阻断导致第一极体（PB1）排出失败、染色体错位和 MII 板变厚。我们进一步发现，特异性和高效 CK1 抑制剂 D4476 降低了 PB1 排出的速度。此外，D4476 导致巨极体排出、卵母细胞前 MI 阻滞、染色体汇聚失败和胚胎发育潜能受损。此外，我们还使用了吡嗪并[1,2-a]嘧啶-1,4-二酮（PP），一种 CK1α 的别构激活剂，以增强卵母细胞中的 CK1α 活性。PP 的补充诱导卵母细胞减数成熟失败、严重的汇聚异常和染色体错位。总之，我们的研究首次表明 CK1α 是卵母细胞减数成熟和早期胚胎发育过程中染色体排列和分离所必需的。
