Data from: Pan-African phylogeography of a model organism, the African clawed frog "Xenopus laevis"

The African clawed frog Xenopus laevis has a large native distribution over much of sub-Saharan Africa and is a model organism for research, a proposed disease vector, and an invasive species. Despite its prominent role in research and abundance in nature, surprisingly little is known about the phylogeography and evolutionary history of this group. Here we report an analysis of molecular variation of this clade based on 17 loci (one mitochondrial, 16 nuclear) in up to 159 individuals sampled throughout its native distribution. Phylogenetic relationships among mitochondrial DNA haplotypes were incongruent with those among alleles of the putatively female-specific sex-determining gene DM-W, in contrast to the expectation of strict matrilineal inheritance of both loci. Population structure and evolutionarily diverged lineages were evidenced by analyses of molecular variation in these data. These results further contextualize the chronology, and evolutionary relationships within this group, support the recognition of X. laevis sensu stricto, X. petersii, X. victorianus, and herein re-validated X. poweri as separate species. We also propose that portions of the currently recognized distributions of X. laevis (north of the Congo Basin) and X. petersii (south of the Congo Basin) be reassigned to X. poweri.

非洲爪蟾（Xenopus laevis）的原生分布范围覆盖撒哈拉以南非洲的大部分区域，该物种既是经典的科研模式生物、潜在的疾病传播媒介，同时也是一类入侵物种。尽管其在科研领域具有重要地位且野外种群数量丰富，但学界对其系统地理学（phylogeography）与演化历程的认知仍相对匮乏。本研究针对覆盖其原生分布区的最多159份个体样本，基于17个基因座（1个线粒体基因座、16个核基因座）对该演化支（clade）的分子变异开展分析。结果显示，线粒体DNA单倍型（haplotype）间的系统发育关系，与推定的雌性特异性性别决定基因DM-W的等位基因（allele）间的系统发育关系并不一致，这与两个基因座均应严格遵循母系遗传（matrilineal inheritance）的理论预期相悖。通过对上述数据的分子变异分析，本研究揭示了该类群的种群结构与演化分化支系。本研究结果进一步厘清了该类群的演化时序与系统发育关系，支持将严格意义上的非洲爪蟾（X. laevis sensu stricto）、彼得氏爪蟾（X. petersii）、维多利亚爪蟾（X. victorianus）以及本文重新验证有效的鲍威尔爪蟾（X. poweri）认定为独立物种。此外，本研究提议将当前认知中刚果盆地以北的X. laevis分布区、以及刚果盆地以南的X. petersii分布区的部分区域，重新划归为X. poweri的分布范围。