No abstract

Lacertid lizards are a widely radiated group of squamate reptiles with long-term stable ZZ/ZW sex chromosomes. Despite their family-wide homology of Z-specific gene content, previous cytogenetic studies revealed significant variability in the size, morphology, and heterochromatin distribution of their W chromosome. However, there is little evidence about the accumulation and distribution of repetitive content on lacertid chromosomes, especially on their W chromosome. In order to expand our knowledge of the evolution of sex chromosome repetitive content, we examined the topology of telomeric and microsatellite motifs that tend to often accumulate on the sex chromosomes of reptiles in the karyotypes of 15 species of lacertids by fluorescence in situ hybridization (FISH). The topology of the above-mentioned motifs was compared to the pattern of heterochromatin distribution, as revealed by C-banding. Our results show that the topologies of the examined motifs on the W chromosome do not seem to follow a strong phylogenetic signal, indicating independent and species-specific accumulations. In addition, the degeneration of the W chromosome can also affect the Z chromosome and potentially also other parts of the genome. Our study provides solid evidence that the repetitive content of the degenerated sex chromosomes is one of the most evolutionary dynamic parts of the genome.

No abstract

The genus Pelophylax has been considered a model organism for understanding hybridization. Despite being the most diverse within the Western Palearctic group of Pelophylax, the ridibundus/bedriagae lineage that includes six species, remains largely understudied, revealing many knowledge gaps in regards to their evolution and conservation. Using genetic data from populations among species inhabiting contact zones could prove vital in filling these gaps. We tested 17 microsatellite markers for cross-species amplification in mainland Pelophylax species distributed in southern Balkans and evaluated their power to successfully detect population/species structure. Importantly, we examined their potential for identifying hybrids and backcrosses between known hybridized species. We detected 12 highly polymorphic loci that cross-amplified all species that showed no significant Linkage Disequilibrium and were able to discriminate among species and between parental and hybrids. We suggest their future use in genetic studies for the genus Pelophylax in Greece, including the identification of contact zones.

No abstract