Laboratory of Fish Genetics, Institute of Animal Physiology and Genetics CAS, v. v. i., 277 21, Libechov, Czech Republic.
Department of Ecology and Evolution, University of Lausanne, Biophore, 1015, Lausanne, Switzerland.
Sci Rep. 2021 Jan 15;11(1):1633. doi: 10.1038/s41598-021-81240-5.
Hybridogenesis is a reproductive tool for sexual parasitism. Hybridogenetic hybrids use gametes from their sexual host for their own reproduction, but sexual species gain no benefit from such matings as their genome is later eliminated. Here, we examine the presence of sexual parasitism in water frogs through crossing experiments and genome-wide data. We specifically focus on the famous Central-European populations where Pelophylax esculentus males (hybrids of P. ridibundus and P. lessonae) live with P. ridibundus. We identified a system where the hybrids commonly produce two types of clonal gametes (hybrid amphispermy). The haploid lessonae genome is clonally inherited from generation to generation and assures the maintenance of hybrids through a process, in which lessonae sperm fertilize P. ridibundus eggs. The haploid ridibundus genome in hybrids received from P. ridibundus a generation ago, is perpetuated as clonal ridibundus sperm and used to fertilize P. ridibundus eggs, yielding female P. ridibundus progeny. These results imply animal reproduction in which hybridogenetic taxa are not only sexual parasites, but also participate in the formation of a sexual taxon in a remarkable way. This occurs through a process by which sexual gametes are being captured, converted to clones, and returned to sexual populations in one generation.
杂种形成是一种性寄生的生殖工具。杂种形成杂种利用其性宿主的配子进行自身繁殖，但性物种不会从这种交配中获益，因为它们的基因组随后被消除。在这里，我们通过交叉实验和全基因组数据来研究水蛙中的性寄生现象。我们特别关注著名的中欧种群，在那里 Pelophylax esculentus 雄蛙（P. ridibundus 和 P. lessonae 的杂种）与 P. ridibundus 共存。我们发现了一个系统，其中杂种通常产生两种类型的克隆配子（杂种两性生殖）。单倍体 lessonae 基因组从一代一代地以克隆方式遗传，并通过一个过程来确保杂种的维持，即 lessonae 精子使 P. ridibundus 卵子受精。来自 P. ridibundus 的前一代杂种中的单倍体 ridibundus 基因组作为克隆 ridibundus 精子得以延续，并用于使 P. ridibundus 卵子受精，产生雌性 P. ridibundus 后代。这些结果表明，动物繁殖中，杂种形成类群不仅是性寄生虫，而且还以显著的方式参与了性分类群的形成。这是通过一个过程实现的，即性配子被捕获、转化为克隆体，并在一代内返回性种群。
