Data from: Limited genomic consequences of hybridization between two African clawed frogs, Xenopus gilli and X. laevis (Anura: Pipidae)

The Cape platanna, Xenopus gilli, an endangered frog, hybridizes with the African clawed frog, X. laevis, in South Africa. Estimates of the extent of gene flow between these species range from pervasive to rare. Efforts have been made in the last 30 years to minimize hybridization between these two species in the west population of X. gilli, but not the east populations. To further explore the impact of hybridization and the efforts to minimize it, we examined molecular variation in one mitochondrial and 13 nuclear genes in genetic samples collected recently (2013) and also over two decades ago (1994). Despite the presence of F1 hybrids, none of the genomic regions we surveyed had evidence of gene flow between these species, indicating a lack of extensive introgression. Additionally we found no significant effect of sampling time on genetic diversity of populations of each species. Thus, we speculate that F1 hybrids have low fitness and are not backcrossing with the parental species to an appreciable degree. Within X. gilli, evidence for gene flow was recovered between eastern and western populations, a finding that has implications for conservation management of this species and its threatened habitat.

开普爪蟾（Cape platanna，学名Xenopus gilli）为濒危蛙类，在南非地区与非洲爪蟾（African clawed frog，X. laevis）存在杂交现象。当前学界对二者间基因交流程度的估算跨度极大，从普遍存在到极为罕见不等。过去30年间，科研人员已针对吉氏爪蟾西部种群开展了降低二者杂交率的相关防控工作，但针对其东部种群尚未采取类似措施。为进一步探究杂交现象的影响以及相关防控工作的成效，本研究对2013年新近采集以及20多年前（1994年）获取的遗传样本中1个线粒体基因与13个核基因的分子变异情况进行了检测。尽管研究中发现了F1代杂交个体，但所有被检测的基因组区域均未发现这两个物种间存在基因交流的证据，表明二者未发生广泛的基因渐渗。此外，本研究未发现采样时间对两个物种种群的遗传多样性存在显著影响。据此我们推测，F1代杂交个体的适合度较低，且未与亲本物种发生显著程度的回交。在吉氏爪蟾种群内部，本研究发现东西部种群间存在基因交流，这一发现对该物种及其受威胁栖息地的保护管理具有重要参考意义。