Picariello, O., B. Safaei-Mahroo & G. Chinali

S1 satellite DNA confirms the species rank of Rana pseudodalmatina Eiselt & Schmidtler, 1971. pp. 269-277.

Abstract. S1 satellite from Palaearctic brown frogs, genus Rana (Ranidae) is the only satellite DNA family in which the ‘most common sequence’ (MCS) and overall variability of repetitive units in the genome has been determined. Both features are species-specific in all European frogs and the same applies to species including their subspecies. This indicates that they were established when each species was forming and remained unchanged to the present. We previously found that both features were the same in all Anatolian taxa (Rana macrocnemis, R. camerani, R. holtzi, R. tavasensis), suggesting that they belong to a single species, R. macrocnemis. In this study we characterized S1 satellite DNA from R. pseudodalmatina from Iran. Southern blots, quantitative dot blots, and FISH analyses produced results similar to those obtained from Anatolian taxa. However, all R. pseudodalmatina specimens contain S1a repetitive units (477 bp) with the same MCS and overall genomic variability that are both different from those of Anatolian taxa, indicating that they belong to a distinct species. S1a MCS from R. pseudodalmatina is more homologous to the corresponding MCSs from all European species than that of R. macrocnemis from which it differs in 22 positions. Our results provide relevant conclusions on the usefulness and limitations of the use of satellite DNA sequences in taxonomic and phylogenetic analyses.

Key words. Amphibia, Anura, Satellite DNA, repetitive units, molecular evolution, taxonomy, brown frogs, Iran.