Comparative Cytogenetics 3(1): 11-24, doi: 10.3897/compcytogen.v3i1.4
Features of the karyotypes of Pelophylax ridibundus Pallas, 1771 and Rana macrocnemis Boulenger, 1885 (Amphibia: Ranidae) from Armenia
A Martirosyan, Ilona Stepanyan
Abstract Сhromosomal complements of Pelophylax ridibundus Pallas, 1771 from 9 localities (Northern, Central and South Armenia) and Rana macrocnemis Boulenger, 1885 from one locality (North-West Armenia) have been analyzed. The chromosome sets of P. ridibundus collected from 8 localities showed 2n=26, (10m+12sm+4st; NF=52). A secondary constriction has been observed in all studied individuals on the 10-th chromosome pair showing NOR-positive reaction. C-positive heterochromatin blocks have been observed on long arms of the 2-nd and 10-th pairs of chromosomes (7 localities). In addition, C-heterochromatin blocks have been found on interstitial regions of short arms of the 12-th pairs, as well as in telomeric regions of long arms of the 9-th pairs and on short arms of the 5-th pair in the frogs from 2 localities. The karyotype of P. ridibundus from populations near Ejmiatsin differs from other populations (2n=26, 12m+10sm+4st). Diploid number of chromosomes of R. macrocnemis was also 26 (8m+12sm+6st, NF=52). Blocks of C-positive heterochromatin have been revealed in telomeric parts of the 1-st, 2-nd (p), 3-rd (q), 4-th (q), 6-th, 9-th (p), 10-th (p,q) and 13-th (q) pairs, as well as in interstitial regions of the 1-st and 2-nd pairs of chromosomes.  Intrapopulation and interpopulation geographic variations of karyotypes and C-heterochromatin banding patterns of P. ridibundus have been revealed. Karyotypically, morphotypes “macrocnemis” and “camerani” are closely related.