Hubrecht Institute, Royal Netherlands Academy of Arts and Sciences and University Medical Center Utrecht, Utrecht, the Netherlands.
PLoS Biol. 2022 May 24;20(5):e3001597. doi: 10.1371/journal.pbio.3001597. eCollection 2022 May.
Polyploid cells contain more than 2 copies of the genome and are found in many plant and animal tissues. Different types of polyploidy exist, in which the genome is confined to either 1 nucleus (mononucleation) or 2 or more nuclei (multinucleation). Despite the widespread occurrence of polyploidy, the functional significance of different types of polyploidy is largely unknown. Here, we assess the function of multinucleation in Caenorhabditis elegans intestinal cells through specific inhibition of binucleation without altering genome ploidy. Through single-worm RNA sequencing, we find that binucleation is important for tissue-specific gene expression, most prominently for genes that show a rapid up-regulation at the transition from larval development to adulthood. Regulated genes include vitellogenins, which encode yolk proteins that facilitate nutrient transport to the germline. We find that reduced expression of vitellogenins in mononucleated intestinal cells leads to progeny with developmental delays and reduced fitness. Together, our results show that binucleation facilitates rapid up-regulation of intestine-specific gene expression during development, independently of genome ploidy, underscoring the importance of spatial genome organization for polyploid cell function.
多倍体细胞含有基因组的 2 个以上拷贝，存在于许多植物和动物组织中。多倍体存在不同的类型，其中基因组局限于 1 个核（单核化）或 2 个或更多核（多核化）。尽管多倍体广泛存在，但不同类型的多倍体的功能意义在很大程度上仍是未知的。在这里，我们通过特异性抑制双核化而不改变基因组倍性来评估 Caenorhabditis elegans 肠道细胞多核化的功能。通过单虫 RNA 测序，我们发现双核化对组织特异性基因表达很重要，特别是在幼虫发育到成年的过渡期间快速上调的基因。受调控的基因包括卵黄蛋白原，其编码卵黄蛋白，有助于将营养物质运输到生殖细胞系。我们发现单核化肠道细胞中卵黄蛋白原表达降低会导致后代发育迟缓且适应性降低。总之，我们的结果表明，双核化在发育过程中促进了肠道特异性基因表达的快速上调，与基因组倍性无关，突出了空间基因组组织对多倍体细胞功能的重要性。
