Center for Interdisciplinary Research in Biology, Collège de France, Université PSL, CNRS, INSERM, 75005 Paris, France.
ARTbio Bioinformatics Analysis Facility, IBPS, CNRS, Sorbonne Université, Institut Français de Bioinformatique, 75005 Paris, France.
Genetics. 2024 Oct 7;228(2). doi: 10.1093/genetics/iyae130.
Germline cells produce gametes, which are specialized cells essential for sexual reproduction. Germline cells first amplify through several rounds of mitosis before switching to the meiotic program, which requires specific sets of proteins for DNA recombination, chromosome pairing, and segregation. Surprisingly, we previously found that some proteins of the synaptonemal complex, a prophase I meiotic structure, are already expressed and required in the mitotic region of Drosophila females. Here, to assess if additional meiotic genes were expressed earlier than expected, we isolated mitotic and meiotic cell populations to compare their RNA content. Our transcriptomic analysis reveals that all known meiosis I genes are already expressed in the mitotic region; however, only some of them are translated. As a case study, we focused on mei-W68, the Drosophila homolog of Spo11, to assess its expression at both the mRNA and protein levels and used different mutant alleles to assay for a premeiotic function. We could not detect any functional role for Mei-W68 during homologous chromosome pairing in dividing germ cells. Our study paves the way for further functional analysis of meiotic genes expressed in the mitotic region.
生殖细胞产生配子，这是有性生殖所必需的特化细胞。生殖细胞在切换到减数分裂程序之前，首先通过几次有丝分裂扩增，减数分裂程序需要特定的蛋白质组用于 DNA 重组、染色体配对和分离。令人惊讶的是，我们之前发现，联会复合体（减数分裂 I 前期的一种结构）的一些蛋白质已经在果蝇雌性的有丝分裂区域表达并需要它们。在这里，为了评估是否有其他减数分裂基因比预期更早表达，我们分离了有丝分裂和减数分裂细胞群体，以比较它们的 RNA 含量。我们的转录组分析表明，所有已知的减数分裂 I 基因都已经在有丝分裂区域表达；然而，只有其中一些被翻译。作为一个案例研究，我们专注于果蝇 Spo11 的同源物 mei-W68，以评估其在 mRNA 和蛋白质水平上的表达，并使用不同的突变等位基因来检测其在减数分裂前的功能。我们无法在有丝分裂的生殖细胞中检测到同源染色体配对过程中 Mei-W68 的任何功能作用。我们的研究为进一步分析在有丝分裂区域表达的减数分裂基因的功能铺平了道路。
