Station d'Ecologie Théorique et Expérimentale, UAR2029, CNRS, Moulis, France.
Present address: NIHR Health Protection Research Unit in Respiratory Infections, National Heart and Lung Institute, Imperial College London, London, UK.
Microb Genom. 2024 Jan;10(1). doi: 10.1099/mgen.0.001175.
The extent of intraspecific genomic variation is key to understanding species evolutionary history, including recent adaptive shifts. Intraspecific genomic variation remains poorly explored in eukaryotic micro-organisms, especially in the nuclear dimorphic ciliates, despite their fundamental role as laboratory model systems and their ecological importance in many ecosystems. We sequenced the macronuclear genome of 22 laboratory strains of the oligohymenophoran , a model species in both cellular biology and evolutionary ecology. We explored polymorphisms at the junctions of programmed eliminated sequences, and reveal their utility to barcode very closely related cells. As for other species of the genus , we confirm micronuclear centromeres as gene diversification centres in , but also reveal a two-speed evolution in these regions. In the rest of the genome, we highlight recent diversification of genes coding for extracellular proteins and cell adhesion. We discuss all these findings in relation to this ciliate's ecology and cellular characteristics.
种内基因组变异的程度是了解物种进化历史的关键，包括最近的适应性变化。尽管真核微生物中的种内基因组变异在实验室模式系统中具有重要作用，并且在许多生态系统中具有重要的生态意义，但在这些微生物中，种内基因组变异仍然没有得到很好的研究，尤其是核二态纤毛虫。我们对寡膜纤毛虫的 22 个实验室菌株的巨核基因组进行了测序，寡膜纤毛虫是细胞生物学和进化生态学的模式物种。我们在程序性消除序列的连接处探索了多态性，并揭示了它们用于对非常密切相关的细胞进行条形码标记的用途。与该属的其他物种一样，我们确认微核着丝粒是基因多样化的中心，但也揭示了这些区域的双速进化。在基因组的其余部分，我们强调了编码细胞外蛋白和细胞黏附的基因的近期多样化。我们将所有这些发现与这种纤毛虫的生态学和细胞特征联系起来进行讨论。
