Research on genetic diversity of the parthenogenetic lizard species (Darevskia arribas, 1997) in Türkiye by using DNA barcoding method

DNA barcoding studies are conducted with the COI (cytochrome oxidase subunit 1) gene, located in the heavy chain region of mitochondrial DNA, known as the barcode gene's Folmer region. Barcoding studies are a highly effective and reliable method used in population genetics, phylogenetic studies, and species differentiation. In this study, the reliability of barcoding studies in species identification and the determination of genetic diversity and kinship was tested. This study aimed to assess the reliability of barcode studies in species differentiation using DNA barcoding and to determine genetic diversity and lineage relationships. For this purpose, 43 specimens of five parthenogenetic Darevskia species from 19 localities in Turkey were analyzed using the COI gene. It was determined that the data set used in the analyzes contained 4 different haplotypes in total. While one of the detected haplotypes represents the D. armeniaca, when the other two haplotypes are taken into consideration, it is seen that D. bendimahiensis and D. sapphirina and D. unisexualis and D. uzzelli share the same haplotype. Finally, a population belonging to the D. unisexualis distributed around Horasan, Erzurum is also seen as a separate haplotype. The results of this study showed that D. bendimahiensis and D. sapphirina, known to be closely related species, exhibited a close genetic relationship, while the DNA barcodes of D. armeniaca were found to be unique to itself and not shared with any other species. Samples of D. unisexualis and D. uzzelli, which are not known to be closely related, showed branching on the same branch in this study. Phylogenetic analyses (Neighbor-Joining, Maximum Likelihood ve Bayesian Inference) were performed to construct the phylogenetic structure among the species. The phylogenetic analysis resulted in the formation of similar tree topologies that support the presence of three monophyletic groups. One of these represents the D. armeniaca, while in the other two, D. unisexualis is sharing the same lineage with D. uzzelli and D. bendimahiensis is sharing the same lineage with D. sapphirina, respectively. To test the potential of the current lineages representing a species, species tree analyses (ABGD, bPTP, mPTP, GMYC and TCS) were performed. The results of ABGD, bPTP, and TCS analyses revealed the formation of three monophyletic groups. The outcomes of these analyses indicated that the three monophyletic lineages identified within the existing group should be considered as separate species. One of the most important findings among all the results obtained is the acceptance of D. bendimahiensis with D. sapphirina and D. unisexualis with D. uzzelli, which are currently recognized as different taxa, as the same species.