Institute of Animal Physiology and Genetics, Laboratory of NonMendelian Evolution, The Czech Academy of Sciences, Liběchov, 277 21, Czech Republic.
Department of Biology and Ecology, Faculty of Science, University of Ostrava, Chittussiho 10, Ostrava, 710 00, Czech Republic.
Sci Rep. 2024 Sep 27;14(1):22221. doi: 10.1038/s41598-024-73043-1.
Gametogenesis produces gametes as a piece of genetic information transmitted to the offspring. While during sexual reproduction, progeny inherits a mix of genetic material from both parents, asexually reproducing organisms transfer a copy of maternal or paternal DNA to the progeny clonally. Parthenogenetic, gynogenetic and hybridogenetic animals have developed various mechanisms of gametogenesis, however, their inheritance is not fully understood. Here, we focused on the inheritance of asexual gametogenesis in hybrid Pelophylax esculentus (RL), emerging after crosses of P. lessonae (LL) and P. ridibundus (RR). To understand the mechanisms of gametogenesis in hybrids, we performed three-generation experiments of sexual P. ridibundus females and hybrids from all-male hybrid populations. Using fluorescent in situ hybridization, micronuclei analysis, flow cytometry and genotyping, we found that most adult hybrid males simultaneously produced two types of clonal sperm. Also, most male tadpole progeny in two successive backcrossed generations simultaneously eliminated L and R parental genomes, while some progeny produced only one type of sperm. We hypothesize that the reproductive variability of males producing two kinds of sperm is an adaptive mechanism to reproduce in mixed populations with P. ridibundus and may explain the extensive distribution of the all-male lineage across the European River Basin.
配子发生产生配子，作为遗传信息传递给后代。在有性生殖过程中，后代从父母双方继承混合的遗传物质，而进行无性繁殖的生物则将母本或父本的 DNA 拷贝传递给克隆后代。孤雌生殖、雌核生殖和杂种生殖的动物已经发展出各种配子发生机制，但其遗传仍不完全清楚。在这里，我们专注于杂种中华大蟾蜍（RL）的无性配子发生的遗传，该杂种是由中华蟾蜍（LL）和金线蛙（RR）杂交产生的。为了了解杂种配子发生的机制，我们进行了三代表型实验，涉及有性金线蛙雌性和来自全雄杂种群体的杂种。通过荧光原位杂交、微核分析、流式细胞术和基因分型，我们发现大多数成年杂种雄性同时产生两种类型的克隆精子。此外，在连续两代回交中，大多数雄性蝌蚪后代同时消除了 L 和 R 亲代基因组，而一些后代只产生一种类型的精子。我们假设产生两种精子的雄性的生殖变异性是一种适应机制，可在与金线蛙混合的种群中繁殖，这可能解释了全雄谱系在整个欧洲流域的广泛分布。
