Structural dissection of male meiosis in C. elegans

减数分裂是所有有性生殖生物的基本生物学过程。在生殖细胞中，减数分裂使产生配子的染色体数量减半，并促进遗传变异。雌性减数分裂产生1个单倍体卵和2个无功能极体，而雄性减数分裂产生4个功能单倍体精细胞。令人惊讶的是，我们对以中心体为基础的雄性减数分裂纺锤体的组织知之甚少，我们迫切需要分析这些纺锤体的动力学和超微结构。利用秀丽隐杆线虫动物模型的优势，我们的目的是通过光镜和电镜对雄性减数分裂进行解剖。我们建议：1)分析野生型雄性的纺锤体动力学，2)操纵单价性染色体的分离，3)通过电子断层扫描定量表征野生型纺锤体，4)分析突变纺锤体的超微结构。预计这种方法将导致对男性减数分裂的基本见解，并将为这一高度未充分研究的生物过程的机制表征开辟新的研究途径。

Meiosis is a fundamental biological process of all sexually reproducing organisms. Restricted to germ cells, meiosis halves the number of chromosomes in producing gametes and promotes genetic variability. Whereas female meiosis produces one haploid egg and two non-functional polar bodies, male meiosis produces four functional haploid sperm cells. Surprisingly little is known about the organization of the centrosome-based male meiotic spindles, and we urgently need to analyze the dynamics and the ultrastructure of these spindles. Taking advantage of the strengths of the animal model Caenorhabditis elegans, we aim to dissect male meiosis by applying both light and electron microscopy. We propose to: 1) analyze spindle dynamics in wild-type males, 2) manipulate the segregation of the univalent sex chromosome, 3) quantitatively characterize wild-type spindles by electron tomography, and 4) analyze the ultrastructure of mutant spindles. It is anticipated that this approach will lead to fundamental insights into male meiosis and will open up new avenues of research for a mechanistic characterization of this highly understudied biological process.