Molecular phylogeny of Eremias spp. from Pakistan contributes to a better understanding of the diversity of racerunners

Museomics help resolving the phylogeny of snowfinches (Aves, Passeridae, Montifringilla and allies)

Historical specimens from museum collections provide a valuable source of material also from remote areas or regions of conflict that are not easily accessible to scientists today. With this study, we are providing a taxon-complete phylogeny of snowfinches using historical DNA from whole skins of an endemic species from Afghanistan, the Afghan snowfinch, Pyrgilauda theresae. To resolve the strong conflict between previous phylogenetic hypotheses, we generated novel mitogenome sequences for selected taxa and genome-wide SNP data using ddRAD sequencing for all extant snowfinch species endemic to the Qinghai-Tibet Plateau (QTP) and for an extended intraspecific sampling of the sole Central and Western Palearctic snowfinch species (Montifringilla nivalis). Our phylogenetic reconstructions unanimously refuted the previously suggested paraphyly of genus Pyrgilauda. Misplacement of one species-level taxon (Onychostruthus tazcanowskii) in previous snowfinch phylogenies was undoubtedly inferred from chimeric mitogenomes that included heterospecific sequence information. Furthermore, comparison of novel and previously generated sequence data showed that the presumed sister-group relationship between M. nivalis and the QTP endemic M. henrici was suggested based on flawed taxonomy. Our phylogenetic reconstructions based on genome-wide SNP data and on mitogenomes were largely congruent and supported reciprocal monophyly of genera Montifringilla and Pyrgilauda with monotypic Onychostruthus being sister to the latter. The Afghan endemic P. theresae likely originated from a rather ancient Pliocene out-of-Tibet dispersal probably from a common ancestor with P. ruficollis. Our extended trans-Palearctic sampling for the white-winged snowfinch, M. nivalis, confirmed strong lineage divergence between an Asian and a European clade dated to 1.5 - 2.7 million years ago (mya). Genome-wide SNP data suggested subtle divergence among European samples from the Alps and from the Cantabrian mountains.

Range-Wide Phylogeography and Ecological Niche Modeling Provide Insights into the Evolutionary History of the Mongolian Racerunner (Eremias argus) in Northeast Asia

The Mongolian racerunner, Eremias argus, is a small lizard endemic to Northeast Asia that can serve as an excellent model for investigating how geography and past climate change have jointly influenced the evolution of biodiversity in this region. To elucidate the processes underlying its diversification and demography, we reconstructed the range-wide phylogeographic pattern and evolutionary trajectory, using phylogenetic, population genetic, landscape genetic, Bayesian phylogeographic reconstruction and ecological niche modeling approaches. Phylogenetic analyses of the mtDNA cyt b gene revealed eight lineages that were unbounded by geographic region. The genetic structure of E. argus was mainly determined by geographic distance. Divergence dating indicated that E. argus and E. brenchleyi diverged during the Mid-Pliocene Warm Period. E. argus was estimated to have coalesced at~0.4351 Ma (Marine Isotope Stage 19). Bayesian phylogeographic diffusion analysis revealed out-of-Inner Mongolia and rapid colonization events from the end of the Last Interglacial to the Last Glacial Maximum, which is consistent with the expanded suitable range of the Last Glacial Maximum. Pre-Last Glacial Maximum growth of population is presented for most lineages of E. argus. The Glacial Maximum contraction model and the previous multiple glacial refugia hypotheses are rejected. This may be due to an increase in the amount of climatically favorable habitats in Northeast Asia. Furthermore, E. argus barbouri most likely represents an invalid taxon. The present study is the first to report a range-wide phylogeography of reptiles over such a large region in Northeast Asia. Our results make a significant contribution towards understanding the biogeography of the entire Northeast Asia.

Taxonomic diversity of racerunners with descriptions of two new Eremias species (Sauria: Lacertidae) from Central Iran

We provide a diversity assessment of Iranian species of the genus Eremias based on the cytochrome oxidase I mtDNA gene fragment. We analyzed 93 genetic samples from the entire distribution of the Eremias fasciata species complex in Iran and surrounding regions, along with morphological data to support the description of two new species from Central Iran. We hypothesize that the diversification of the Eremias fasciata species complex was largely influenced by the fragmentation of sand massifs in the region. This same hypothesis has been used to explain the high level of endemism among the sand-dwelling species of reptiles along the Iranian Plateau in the same area. The two new species described herein can be distinguished from other congeneric species by their phylogenetic position and a combination of morphological characters. We use these data to discuss the taxonomy of Eremias based on morphology, habitat choice, and genetic data.

Complete mitochondrial genome of the Kyrghyz racerunner (Eremias nikolskii Bedriaga, 1905) from Kyrgyzstan

The complete mitochondrial genome (mitogenome) of the Kyrghyz racerunner (Eremias nikoskii Bedriaga, 1905) from Kyrgyzstan was determined for the first time by next-generation sequencing. The mitogenome was 20,840 bp in length and comprised the standard set of 13 protein-coding genes (PCGs), 2 ribosomal RNA genes, 22 transfer RNA genes, and a control region. The 13 concatenated PCGs were used to implement Bayesian phylogenetic analyses together with some congeners and three representative lacertids retrieved from GenBank. The monophyly of both Eremias and its viviparous group was recovered in the Bayesian phylogenetic tree, while the subgenus Pareremias was paraphyletic with respect to E. nikoskii. The mitogenome of E. nikoskii will faciliate the research on species delimitation, molecular evolution, and phylogenetic inference in the racerunner lizards.

Complete Mitochondrial Genomes of Five Racerunners (Lacertidae: Eremias) and Comparison with Other Lacertids: Insights into the Structure and Evolution of the Control Region

Comparative studies on mitochondrial genomes (mitogenomes) as well as the structure and evolution of the mitochondrial control region are few in the Lacertidae family. Here, the complete mitogenomes of five individuals of Eremias scripta (2 individuals), Eremias nikolskii, Eremias szczerbaki, and Eremias yarkandensis were determined using next-generation sequencing and were compared with other lacertids available in GenBank. The circular mitogenomes comprised the standard set of 13 protein-coding genes (PCGs), 22 transfer RNA genes, 2 ribosomal RNA genes and a long non-coding control region (CR). The extent of purifying selection was less pronounced for the COIII and ND2 genes in comparison with the rest of the PCGs. The codons encoding Leucine (CUN), Threonine, and Isolecucine were the three most frequently present. The secondary structure of rRNA of Lacertidae (herein, E. scripta KZL15 as an example) comprised four domains and 28 helices for 12S rRNA, with six domains and 50 helices for 16S rRNA. Five types and twenty-one subtypes of CR in Lacertidae were described by following the criteria of the presence and position of tandem repeats (TR), termination-associated sequence 1 (TAS1), termination-associated sequence 2 (TAS2), conserved sequence block 1 (CBS1), conserved sequence block 2 (CSB2), and conserved sequence block 3 (CSB3). The compositions of conserved structural elements in four genera, Acanthodactylus, Darevskia, Eremias, and Takydromus, were further explored in detail. The base composition of TAS2 - TATACATTAT in Lacertidae was updated. In addition, the motif "TAGCGGCTTTTTTG" of tandem repeats in Eremias and the motif "GCGGCTT" in Takydromus were presented. Nucleotide lengths between CSB2 and CSB3 remained 35 bp in Eremias and Darevskia. The phylogenetic analyses of Lacertidae recovered the higher-level relationships among the three subfamilies and corroborated a hard polytomy in the Lacertinae phylogeny. The phylogenetic position of E. nikolskii challenged the monophyly of the subgenus Pareremias within Eremias. Some mismatches between the types of CR and their phylogeny demonstrated the complicated evolutionary signals of CR such as convergent evolution. These findings will promote research on the structure and evolution of the CR and highlight the need for more mitogenomes in Lacertidae.

Out of the blue: The first record of the genus Heremites Gray, 1845 (Squamata, Scincidae) from Pakistan

The genus Heremites Gray, 1845 is endemic to the Western Palearctic region, containing morphologically similar species with a not well resolved taxonomy. The genus has a broad distribution from North Africa to Central Asia, with the only known record from northeastern Afghanistan. Three species are currently recognized in the genus with one, H.septemtaeniatus (Reuss, 1834), representing populations at the eastern edge of the genus range. During extensive fieldwork, we discovered H.septemtaeniatus from northwestern Pakistan and provisionally suggest that this population could be morphologically defined as H.septemtaeniatustranscaucasicus (Chernov, 1926). This important contribution to the knowledge regarding the family Scincidae in Pakistan, however, needs further investigation using an integrative approach.