Abstract 3
Molecular analysis of phylogenetic relationship
among Balkanian green frogs
My thesis work focused on analysis of phylogenetic relationships existing between green frogs of the Balkan’s area.
Located at the margin of the Eurasian and African plates, the Hellenic area of the east Mediterranean region has experienced tremendous geological alterations since the late Tertiary, including multiple events of land fragmentation and connection. Such connections offered opportunities for biological dispersal as well as contacts among previously isolated taxa, won the contrary submergence of land bridges brought about distributive isolation among taxa.
Geological and genetic studies, indicates that the water frog living on Crete, diverged from the other western Paleartic water frogs from a minimum of 5 million years and a maximum of 6 million years ago, while the water frogs of Karphatos and Rhodes diverged from Anatolian relatives about 3 million years ago.
In order to perform a molecular analysis of the phylogenetic relationships among four taxa of green frogs living in the Mediterranean area ( Rana cretensis from Crete, Rana cerigensis from Rhodes, Rana ridibunda from various region of Balkan area and Rana bedriagae from Anatolian peninsula), I analyzed genomic organization and chromosomal localization of centromeric satellite DNA RrS1. The elements of RrS1 family, isolated for the first time in R.ridibunda from Poland, are differentially organized and arranged in other green frog species.
Abstract 4
Using molecular methods, such as Sothern blot, fluorescence in situ hybridization (FISH), PCR with degenerated primers, bioinformatic analysis of sequences, I highlighted that:
- in the examined taxa, RrS1-like sequences show a centromeric hybridization pattern, revealing distinction in different species;
- Southern Blot experiments reveal a different hybridization pattern suggesting a different genomic organization of RrS1 sequences;
- RrS1 sequences isolated from genome of R.ridibunda, shows a higher nucleotide similarity with the sequences of R.cerigensis compared to the ones of R.cretensis.
These studies are compatible with the s island-continent separation hypothesis, previously formulated on the basis of geological and genetic data.
