Department of Biology, Johns Hopkins University, Baltimore, Maryland 21218.
Temasek Life Sciences Laboratory, National University of Singapore, Singapore 11760.
Genetics. 2018 Feb;208(2):435-471. doi: 10.1534/genetics.117.300208.
Gametogenesis represents the most dramatic cellular differentiation pathways in both female and male flies. At the genome level, meiosis ensures that diploid germ cells become haploid gametes. At the epigenome level, extensive changes are required to turn on and shut off gene expression in a precise spatiotemporally controlled manner. Research applying conventional molecular genetics and cell biology, in combination with rapidly advancing genomic tools have helped us to investigate (1) how germ cells maintain lineage specificity throughout their adult reproductive lifetime; (2) what molecular mechanisms ensure proper oogenesis and spermatogenesis, as well as protect genome integrity of the germline; (3) how signaling pathways contribute to germline-soma communication; and (4) if such communication is important. In this chapter, we highlight recent discoveries that have improved our understanding of these questions. On the other hand, restarting a new life cycle upon fertilization is a unique challenge faced by gametes, raising questions that involve intergenerational and transgenerational epigenetic inheritance. Therefore, we also discuss new developments that link changes during gametogenesis to early embryonic development-a rapidly growing field that promises to bring more understanding to some fundamental questions regarding metazoan development.
配子发生代表了雌性和雄性果蝇中最显著的细胞分化途径。在基因组水平上，减数分裂确保了二倍体生殖细胞成为单倍体配子。在表观基因组水平上，需要广泛的变化才能以精确的时空控制方式开启和关闭基因表达。应用传统分子遗传学和细胞生物学的研究，结合快速发展的基因组工具，帮助我们研究了（1）生殖细胞如何在整个成年生殖寿命中保持谱系特异性；（2）哪些分子机制确保了适当的卵子发生和精子发生，并保护生殖系的基因组完整性；（3）信号通路如何有助于生殖细胞与体细胞的通讯；以及（4）这种通讯是否重要。在本章中，我们强调了最近的发现，这些发现提高了我们对这些问题的理解。另一方面，在受精时重新开始新的生命周期是配子面临的独特挑战，提出了涉及代际和跨代表观遗传遗传的问题。因此，我们还讨论了将配子发生过程中的变化与早期胚胎发育联系起来的新进展——这是一个快速发展的领域，有望为一些关于后生动物发育的基本问题带来更多的理解。
