Pan‐African phylogeography of a model organism, the African clawed frog ‘Xenopus laevis’

Abstract

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 revalidated 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.

Evolution of vocal patterns: tuning hindbrain circuits during species divergence

“…Three relatively recently (8.5Mya) diverged species within the laevis clade -X. laevis, X. petersii and X. victorianus (Furman et al, 2015) -produce male advertisement calls with distinct temporal properties (Tobias et al, 2011). All of these species produce advertisement calls that include fast trills, but call duration and period are significantly different across all three species, with X. laevis having the longest call duration and period and X. victorianus having the shortest.…”

“…After 10 min of habituation, a conspecific female was placed in the tank for 30-45 min or overnight during a soundactivated recording (Audacity ® , http://www.audacityteam.org/). Vocalizations were recorded with a hydrophone (CA30 or H2a, Aquarian Audio Products, Shoreline, WA, USA); the signal was The X. laevis clade includes four species: X. laevis, X. petersii, X. victorianus and X. poweri, estimated to have diverged from their most recent common ancestor 8.5 Mya (Furman et al, 2015). (B-D) Representative male advertisement calls in X. laevis, X. petersii and X. victorianus consist of a series of sound pulses (trills) with characteristic temporal patterns and rates (Hz).…”

“…The laevis clade -X. laevis sensu lato -consists of four geographically separated species that diverged ∼8.5 Mya (Furman et al, 2015;Evans et al, 2004;Fig. 1A), each with a distinctive advertisement call (Tobias et al, 2011;e.g.…”

Molecular Polymorphism and Divergence of Duplicated Genes in Tetraploid African Clawed Frogs <b><i>(Xenopus)</i></b>

“…Divergence of X. victorianus and X. laevis (indicated by τ 4 in fig. 1 ) occurred ∼ 10 Mya based on multilocus data from the autosomes [Furman et al, 2014] and mitochondrial DNA [Evans et al, 2004]. An estimate of the time the tetraploid ancestor of these species originated (τ 2 in fig.…”

Exploration into the hidden world of Mozambique’s sky island forests: new discoveries of reptiles and amphibians

“…Poynton and Broadley (1991) report no records of X. laevis for northern Mozambique, but do report it from southern Malawi. The Malawi population has been confirmed by molecular analyses to be X. laevis (Furman et al 2015).…”