Genetic structure of water frog population systems

We are investigating the distributions, population systems, genetic structure, types of gametes, and morphological variability of water frogs of the genus Pelophylax using morphological traits combined with DNA flow cytometry and a multilocus approach (fragments of a nuclear and two mitochondrial genes). Molecular analysis showed the presence of mitochondrial and nuclear DNA introgression of the Anatolian marsh frog (P. cf. bedriagae) into both P. ridibundus and P. esculentus. The observations of alleles and haplotypes of P. cf. bedriagae in P. ridibundus and P. esculentus individuals from the same localities suggest de novo formation of local hybrids. However, the presence of the Balkan marsh frog (P. kurtmuelleri) haplotypes in local hybrids supports the hypothesis regarding the migration of old hemiclonal lineages from glacial refugia or new case of water frogs invasion into water bodies.

The Anomaly P syndrome in amphibians

In the 1950s, famous French writer and biologist Jean Rostand (1894 - 1977) discovered morphological anomalies of an unknown etiology in water frogs of the genus Pelophylax, which he named “the anomaly P”. The anomaly P is the morphological deformations of water frogs that have light and severe forms of manifestation.
The light form of the anomaly is symmetrical polydactyly. Specimens suffering from severe forms of the anomaly have symmetrical brachymely, polydactyly, hind limb edema, bone outgrowths, spikes, flexions, and additional limbs in the inguinal region. The experiments with direct cercariae exposure provide compelling evidence that Strigea robusta (Trematoda: Strigeidae) leads to anomaly P in tadpoles of water frogs. The manifestation of anomaly P turned out to be dependent on the stage of development, cercariae dose, and the location of the cysts.