Allozyme variation in Rattus rattus (Rodentia: Muridae) in Turkey, with particular emphasis on the taxonomy

Abstract

The Turkish black rat "Rattus rattus" shows variation in coat colour corresponding to the occurrence of three subspecies with intermediate colour stages: Rattus rattus rattus, Rattus r. alexandrinus and Rattus r. frugivorus. Turkish black rat populations were divided geographically into six sub-populations: Rr1 = Northwest Anatolia, Rr2 = Central Anatolia, Rr3 = Eastern Mediterranean, Rr4 = Western Mediterranean, Rr5 = Turkish Thrace, and Rr6 = Black Sea region. Genetic variation was assessed using twenty two isoenzyme systems. Seven of twenty-two loci (Pgm-1, Hk, Ale-M, G3pdh, Gpdh-1, Gpi, Fum-1) were found to be polymorphic. The mean Value of F(ST) is found to be 0.073, indicating 7.3 % genetic variation among groups and suggesting the existence of a moderate differentiation between sub-populations of the Turkish black rat. Overall mean heterozygosity (Ho = direct count) for sub-populations was Ho = 0.020, ranging from 0.008 to 0.031. Nei's measure of genetic distance showed that Rr2 and Rr6 were the most identical and sub-populations Rr1 and Rr5 had diverged the most.