Whitehead Institute, Cambridge, Massachusetts, USA.
Nat Genet. 2013 Aug;45(8):877-83. doi: 10.1038/ng.2672. Epub 2013 Jun 16.
Oogenesis is the process by which ovarian germ cells undertake meiosis and differentiate to become eggs. In mice, Stra8 is required for the chromosomal events of meiosis to occur, but its role in differentiation remains unknown. Here we report Stra8-deficient ovarian germ cells that grow and differentiate into oocyte-like cells that synthesize zonae pellucidae, organize surrounding somatic cells into follicles, are ovulated in response to hormonal stimulation, undergo asymmetric cell division to produce a polar body and cleave to form two-cell embryos upon fertilization. These events occur without premeiotic chromosomal replication, sister chromatid cohesion, synapsis or recombination. Thus, oocyte growth and differentiation are genetically dissociable from the chromosomal events of meiosis. These findings open to study the independent contributions of meiosis and oocyte differentiation to the making of a functional egg.
卵子发生是卵巢生殖细胞进行减数分裂和分化为卵子的过程。在小鼠中，Stra8 对于减数分裂的染色体事件的发生是必需的，但它在分化中的作用尚不清楚。在这里，我们报告了 Stra8 缺陷的卵巢生殖细胞，它们生长并分化为卵母细胞样细胞，合成透明带，将周围的体细胞组织成卵泡，对激素刺激排卵，经历不对称细胞分裂产生极体，并在受精时分裂形成二细胞胚胎。这些事件发生时没有减数分裂的染色体复制、姐妹染色单体的黏合、联会或重组。因此，卵母细胞的生长和分化在遗传上与减数分裂的染色体事件是可分离的。这些发现为研究减数分裂和卵母细胞分化对功能性卵子形成的独立贡献开辟了道路。
