Polymerase chain reaction primers for microsatellite loci in the north European water frogs Rana ridibunda and R. lessonae

The marsh frog Rana ridibunda, the pool frog R. lessonae and their hybrid, the edible frog R. esculenta, are members of the complex group of western palearctic water frogs. There has been much interest in these amphibians because they exhibit hybridogenesis, a condition in which fertile hybrids persist with one parental species over multiple generations ( 6). So far mainly allozymes have been used to unravel the complex relationships of these frogs ( 2) although random amplified polymorphic DNA (RAPD) markers have also been developed ( 7). However, in order to study population genetics and hybridogenesis in more detail, more sensitive markers are needed. We report in this paper the characterization of nine polymorphic microsatellite loci, five of which occur in R. lessonae and six in R. ridibunda