Sun Xianfei, Cohen Paula E
Department of Biomedical Sciences, Cornell University, Ithaca, NY, USA.
Methods Mol Biol. 2013;957:1-18. doi: 10.1007/978-1-62703-191-2_1.
Meiosis is the specialized cell division in sexually reproducing organisms in which haploid gametes are produced. Meiotic prophase I is the defining stage of meiosis, when pairing and synapsis occur between homologous chromosomes, concurrent with reciprocal recombination (or crossing over) events that arise between them. Any disruption of these events during prophase I can lead to improper segregation of homologous chromosomes which can cause severe birth defects in the resulting progeny, and this occurs with alarming frequency in human oocytes. Thus, while the pathways that regulate these events in prophase I are highly conserved in both males and females, the stringency with which these events are monitored and/or controlled appears to be dramatically lower in females. These observations underscore the need to examine and compare meiotic mechanisms across the sexes. However, the study of female meiosis is impeded by the early start of meiosis during fetal development and the very limited amount of ovarian tissue available for meiotic analyses. Here we describe three different techniques which are useful for meiotic prophase I analysis in mouse/human oocytes, ranging from early prophase I events through until the resolution of crossing over at the first and second meiotic divisions.
减数分裂是有性生殖生物中产生单倍体配子的特殊细胞分裂过程。减数第一次分裂前期是减数分裂的决定性阶段，此时同源染色体之间发生配对和联会，同时它们之间会发生相互重组（或交叉互换）事件。减数第一次分裂前期这些事件的任何破坏都可能导致同源染色体分离异常，进而在后代中引发严重的出生缺陷，而这种情况在人类卵母细胞中出现的频率令人担忧。因此，虽然在雄性和雌性中调控减数第一次分裂前期这些事件的途径高度保守，但在雌性中对这些事件进行监测和/或控制的严格程度似乎要低得多。这些观察结果强调了跨性别研究减数分裂机制的必要性。然而，雌性减数分裂的研究受到胎儿发育期间减数分裂早期开始以及可用于减数分裂分析的卵巢组织非常有限的阻碍。在这里，我们描述了三种不同的技术，这些技术对于小鼠/人类卵母细胞减数第一次分裂前期的分析很有用，涵盖从减数第一次分裂前期早期事件到第一次和第二次减数分裂中交叉互换的解决。
