Molecular genetic characteristics of Darevskia portschinskii lizard populations based on microsatellite markers analysis

The Caucasian rock lizard species Darevskia portschinskii is one of the bisexual species participating in interspecific hybridisation as the paternal ancestor with the maternal ancestors D. mixta and D. raddei resulting in the successful formation of the parthenogenetic D. dahli and D. rostombekowi, respectively. Populations of D. portschinskii have been previously divided into two subspecies, D. p. portschinskii and D. p. nigrita according to their geographical distribution and the morphological data, but they have not been characterised genetically. Here, we used ten microsatellite markers to determine the genetic structure of the D. portschinskii populations. The utility of the developed microsatellite markers for investigating the genetic variability within and among populations with a heterogeneous spatial distribution was demonstrated. Our results showed that the intra- and interspecific differentiation of the studied populations were consistent with the morphological data on the subspecies status of the D. p. portschinskii and D. p. nigrita populations. A potential applicability of the developed microsatellite markers to study genetic diversity of Darevskia species and subspecies complexes is suggested

Clonal diversity and clone formation in the parthenogenetic Caucasian rock Lizard Darevskia dahli [corrected].

The all-female Caucasian rock lizard species Darevskia dahli and other parthenogenetic species of this genus reproduce normally via true parthenogenesis. Previously, the genetic diversity of this species was analyzed using allozymes, mitochondrial DNA, and DNA fingerprint markers. In the present study, variation at three microsatellite loci was studied in 111 specimens of D. dahli from five populations from Armenia, and new information regarding clonal diversity and clone formation in D. dahli was obtained that suggests a multiple hybridization origin. All individuals but one were heterozygous at the loci studied. Based on specific allele combinations, 11 genotypes were identified among the individuals studied. Individuals with the same genotypes formed distinct clonal lineages: one major clone was represented by 72 individuals, an intermediate clone was represented by 21 individuals, and nine other clones were rare and represented by one or several individuals. A new approach based on the detection and comparison of genotype-specific markers formed by combinations of parental-specific markers was developed and used to identify at least three hybridization founder events that resulted in the initial formation of one major and two rare clones. All other clones, including the intermediate and seven rare clones, probably arose through postformation microsatellite mutations of the major clone. This approach can be used to identify hybridization founder events and to study clone formation in other unisexual taxa

Clonal Diversity and Clone Formation in the Parthenogenetic Caucasian Rock Lizard <i>Darevskia dahlia</i>

<div><p>The all-female Caucasian rock lizard species <i>Darevskia dahli</i> and other parthenogenetic species of this genus reproduce normally via true parthenogenesis. Previously, the genetic diversity of this species was analyzed using allozymes, mitochondrial DNA, and DNA fingerprint markers. In the present study, variation at three microsatellite loci was studied in 111 specimens of <i>D. dahli</i> from five populations from Armenia, and new information regarding clonal diversity and clone formation in <i>D. dahli</i> was obtained that suggests a multiple hybridization origin. All individuals but one were heterozygous at the loci studied. Based on specific allele combinations, 11 genotypes were identified among the individuals studied. Individuals with the same genotypes formed distinct clonal lineages: one major clone was represented by 72 individuals, an intermediate clone was represented by 21 individuals, and nine other clones were rare and represented by one or several individuals. A new approach based on the detection and comparison of genotype-specific markers formed by combinations of parental-specific markers was developed and used to identify at least three hybridization founder events that resulted in the initial formation of one major and two rare clones. All other clones, including the intermediate and seven rare clones, probably arose through postformation microsatellite mutations of the major clone. This approach can be used to identify hybridization founder events and to study clone formation in other unisexual taxa.</p></div

Schematic representation of the SP network that reflects relationship between genotypes 1–9 in <i>D. dahli.</i>

<p>Complete sequences of <i>D. dahli</i> genotypes were analyzed using TCS software version 1.21. Genotypes 10 and 11 are plotted separately. Population distribution of the genotypes is shown by different colours. The black circles show, unsampled, but computer-predicted genotypes.</p

Map of Armenia with the distribution of localities from which parthenogenetic <i>Darevskia dahli</i> populations were collected.

<p>Sampling localities are indicated by different colours. Papanino (+40° 42′ 27.76″, +44° 45′ 43.89″), Phioletovo (+40° 44′ 29.53″, +44° 39′ 31.25″), Vaagni (+40° 52′ 19.16″, +44° 31′ 28.60″), Dzoraget (+40° 54′ 15.02″, +44° 40′ 37.78″), Dendropark (+40° 59′ 30.55″, +44° 21′ 50.79″).</p

Allelic variations of microsatellite containing loci Du215, Du281, and Du323 in parthenogenetic <i>D. dahli</i> species.

1<p>Distances before (−) and after (+) microsatellite cluster are given in bp.</p

Schematic representation of 11 genotypes formed by allelic combinations of microsatellite loci Du215, Du281, and Du323 in 111 <i>D. dahli</i> individuals.

<p>Parental-specific SNV markers are shown in square. Variable microsatellite clusters are shown in each of two alleles.</p

Sample size, combined genotype structure, diversity and distribution in the <i>D. dahli</i> populations.

<p>Pa – Papanino.</p><p>Ph – Phioletovo.</p><p>Va – Vaagni.</p><p>Dz – Dzoraget.</p><p>De – Dendropark.</p