PROJECT 2: TRANSLATIONAL REGULATION OF THE MEIOTIC CELL CYCLE IN THE MALE.

减数分裂是生殖细胞发育程序的标志性事件，对于有性生殖来说是绝对必要的 繁殖的真核生物。适当地调节减数分裂进程是生产功能性 配子。减数分裂的一个关键方面是生殖细胞特有的细胞周期，在这个周期中，dna合成的最后一轮。 (S减数分裂前)之后是一个大大延长的G2期，称为减数分裂前期，在两次减数分裂之前 组织。这种标志性的细胞周期延迟为同源染色体配对、突触提供了关键时间 和重组，以及驱动配子分化的主要生物合成事件。在卵母细胞中， 产生卵子并为早期做准备的转录、翻译和形态发生变化 胚胎发育主要在减数分裂前期完成。在雄性生殖细胞中，尽管戏剧性的 产生成熟配子的形态变化发生在减数分裂之后，减数分裂是基因的主要部分。 建立精子发生的表达程序发生在减数分裂的前期。在两性中，减数分裂 减数分裂的开始、进展、成熟和激活是关键的调控点。理解 如何调控这些事件是理解减数分裂停滞不育的分子基础的关键，对于 设计有效的策略来区分生殖细胞和胚胎前体细胞，并为发育和 在体外成熟的合格配子。U54合作中心这个子项目中提出的分析 生殖和干细胞生物学将阐明控制细胞周期的基本机制 减数分裂前期，包括首先暂停细胞周期，然后激活细胞周期的关键控制电路 一旦配子发生的程序得到适当的表达，减数分裂I的G2/M转变。

Meiosis is the signature event of the germ cell developmental program, absolutely required for sexual reproduction eukaryotes. Proper regulation of meiotic progression is crucial for production of functional gametes. A key aspect of meiosis is a germ cell specific cell cycle, in which a final round of DNA synthesis (premeiotic S) is followed by a greatly extended G2, termed meiotic prophase, prior to the two meiotic divisions. This signature cell cycle delay provides critical time for homologous chromosomes to pair, synapse and recombine, as well as for major biosynthetic events that drive gamete differentiation. In oocytes, the transcriptional, translational and morphogenetic changes that produce the egg and prepare for early embryogenesis are largely accomplished during meiotic prophase. In male germ cells, although dramatic morphological changes that produce mature gametes occur after the meiotic divisions, a major part of the gene expression program that sets up spermiogenesis takes place during meiotic prophase. In both sexes, meiotic onset, progression, maturation, and activation of the meiotic divisions are key regulatory points. Understanding how these events are regulated is key for understanding the molecular basis of meiotic arrest infertility, for designing effective strategies for differentiating germ cells from embryonic precursors, and for developing and maturing competent gametes in vitro. The analysis proposed in this subproject of the U54 Cooperative Center for Reproductive and Stem Cell Biology will elucidate fundamental mechanisms that control the cell cycle for meiotic prophase, including the critical control circuits that first pause the cell cycle, then finally activate the G2/M transition for meiosis I once proper expression of the program for gametogenesis has been achieved.