Arnce Luke R, Bubnell Jaclyn E, Aquadro Charles F
Department of Molecular Biology and Genetics, Cornell University, Ithaca, NY, USA.
bioRxiv. 2025 May 6:2025.04.30.651540. doi: 10.1101/2025.04.30.651540.
In () encodes a protein essential for germline stem cell daughter (GSC) differentiation in early gametogenesis. Despite its essential role in , direct functional evaluation of in other closely related species reveal this essential function is not necessarily conserved. In , for example, is not essential for GSC daughter differentiation. Here, we generated null alleles using CRISPR-Cas9 in a species more distantly related to , to interrogate whether 's essential GSC differentiation function is novel to the species group or a function more basal to the genus. To further characterize the extent of the functional flexibility of other GSC regulating genes, we generated a gene ortholog dataset for 366 GSC regulating genes essential in across 15 additional and two outgroup species. We find that 's essential GSC function is conserved between and and therefore originated prior to the formation of the species group. Additionally, we find that ~8% of the 366 GSC genes essential in are absent in at least one of the 17 species in our ortholog dataset. These results indicate that developmental systems drift (DSD), in which the specific genes regulating a function may change, but the final phenotype is retained, occurs in stem cell regulation and the production of gametes across species.
在（）中编码一种在早期配子发生过程中对生殖系干细胞子代（GSC）分化至关重要的蛋白质。尽管它在（）中起着至关重要的作用，但对其他密切相关的（）物种中（）的直接功能评估表明，这种重要功能不一定保守。例如，在（）中，（）对于GSC子代分化并非必不可少。在这里，我们在与（）关系更远的一个物种中使用CRISPR-Cas9产生了（）无效等位基因，以探究（）的重要GSC分化功能是（）物种组所特有的，还是（）属更基础的功能。为了进一步表征其他GSC调控基因功能灵活性的程度，我们为在另外15个（）物种和两个外群物种中对（）至关重要的366个GSC调控基因生成了一个基因直系同源数据集。我们发现（）的重要GSC功能在（）和（）之间是保守的，因此在（）物种组形成之前就已出现。此外，我们发现我们直系同源数据集中17个物种中的至少一个物种中不存在对（）至关重要的366个GSC基因中的约8%。这些结果表明，发育系统漂移（DSD），即调节一种功能的特定基因可能会发生变化，但最终表型得以保留，发生在跨（）物种的干细胞调控和配子产生过程中。
