ABSTRACT
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.
ABSTRACT
The Yarkand racerunner, Eremias yarkandensis Blandford, 1875, is only distributed in China and Kyrgyzstan. Its complete mitogenome was determined by next-generation sequencing for the first time. The mitogenome was 18,743 bp in length, including 13 protein-coding genes (PCGs), two ribosomal RNA genes, 22 transfer RNA genes, and 1 control region. Its gene arrangement was similar to the typical mtDNA of vertebrates. The 13 concatenated PCGs were used to perform Bayesian phylogenetic analyses together with several congeners as well as two representative species of Lacerta with mitogenome data in GenBank. The resulting phylogenetic tree recovered the monophyly of both Eremias and its viviparous group, with E. yarkandensis being more closely related to E. przewalskii than to E. dzungarica. The mitogenome of E. yarkandensis will provide fundamental data for the exploration of the mitogenome evolution in racerunners.
ABSTRACT
The Eremias multiocellata-przewalskii species complex is a viviparous group in the genus Eremias, and a well-known representative of taxonomically complicated taxa. Within this complex, a new species - E. dzungarica (Orlova et al., 2017) - has been described recently from western Mongolia and eastern Kazakhstan, with an apparent distribution gap in northwestern China. In this study, we used an integrative taxonomic framework to address whether E. dzungarica indeed occurs in China. Thirty specimens previously classified as E. multiocellata were collected in eastern Kazakhstan and the adjacent Altay region in China. The cytochrome c oxidase I ( COI) barcodes were sequenced and compiled with those from Orlova et al. (2017) and analyzed with the standard and diverse barcoding techniques. We detected an absence of a barcoding gap in this complex, which indicates potential cryptic species in Eremias sp. 3 with high intraspecific diversity and multiple recently evolved species in Clade A. Both BIN and GMYC suggested an unrealistically large number of species (23 and 26, respectively), while ABGD, mPTP and BPP indicated a more conservative number of species (10, 12, and 15, respectively), largely concordant with the previously defined species-level lineages according to phylogenetic trees. Based on molecular phylogeny and morphological examination, all 30 individuals collected in this study were reliably identified as E. dzungarica - a distinct species - confirming the occurrence of this species in the Altay region, Xinjiang, China. Potentially owing to the larger sample size in this study, our morphological analyses revealed many inconsistencies with the original descriptions of E. dzungarica, which were primarily associated with sexual dimorphism and a broader range of values for various traits.
Subject(s)
Animal Distribution , DNA Barcoding, Taxonomic , Lizards/physiology , Animals , China , DNA/genetics , Lizards/classification , Lizards/genetics , Phylogeny , Species SpecificityABSTRACT
Steppe racerunner, Eremias (Eremias) arguta, is one of the most widespread species of the Asian racerunners (genus Eremias). Several subspecies were traditionally recognized however, morphological variability is so high that delimitation of these subspecies was always problematic. Here we present a phylogenetic hypothesis for this species based on cytochrome b sequences (55 samples from 35 populations, 900 bp partial sequences), infer it biogeography and the revise its subspecific structure. Six major phylogenetic lineages were revealed. The southernmost populations (E. a. uzbekistanica) from Uzbekistan form a clade together with the Issyk-Kul Lake subspecies (E. a. darevskii) based on both molecular and morphological evidence. Within more northern populations, there is a split between populations from Northern Caucasus, Europe and Western Kazakhstan (E. a. deserti) and Central and Eastern Kazakhstan populations (E. a. arguta). Transcaucasian (E. a. transcaucasica) steppe racerunners are grouped with Middle Asian populations. Finally, the easternmost samples, assigned to "E. a. potanini" are nested within the E. a. arguta clade. Populations from the Ili River Valley form a separate lineage sister to the clade joining all other E. arguta lineages and might represent a yet undescribed taxon. Species distribution in relation to historical biogeography of Middle Asia is discussed.
