Boundary of the subspecies ranges of the sand lizard Lacerta agilis chersonensis and L. a. exigua (Lacertidae, Squamata) in the Central Chernozem Region according to mitochondrial and nuclear DNA markers
Year: 2026
Type: article
Abstract: This study aimed to clarify the nature and extent of the contact zone between subspecies of the sand lizard Lacerta agilis chersonensis and L. a. exigua in the Central Chernozem Region. Based on mitochondrial DNA (mtDNA) marker analysis, the boundary of their ranges in the studied area is located in the western part of the Kursk region, specifically within the Solntsevsky and Manturovsky districts. No mixed populations were found; the distance between the closest localities of the eastern and southern subspecies was 16 km. Analysis of the nuclear DNA (nDNA) marker revealed the presence of heterozygous, presumably “hybrid” individuals. Among 26 individuals diagnosed by mtDNA as L. a. exigua, only two ones, originating from a locality bordering the eastern subspecies range, were heterozygous. In the sample of 32 individuals carrying L. a. chersonensis mtDNA, seven heterozygotes were identified, dispersed across seven localities, both near the range boundary and at a considerable distance (100–130 km). Notably, no evidence of introgression was found, as no individuals exhibited any combination of mtDNA markers from one subspecies and homozygous nDNA markers from the other subspecies. These findings suggest either “relic” hybridization events extending far westward into the L. a. chersonensis range, but not eastward into the L. a. exigua range, or the reflection of ancestral polymorphism due to incomplete lineage sorting (ILS), i.e., the widespread presence of two allelic variants of the β-fibrinogen gene in the southern subspecies.
Source: Current Studies in Herpetology
Institutions: Tambov State University, Penza State University
Language: English
Subfield: Genetics
Domain: Life Sciences
Open Access status: diamond
OpenAlex ID: W7168300064