author(s)
Derya Çetintürk

abstract
Mitochondrial DNA variations of Turkish Microtus hartingi (Barret-Hamilton 1903) and Microtus lydius (Blackler 1916) species were investigated with regard to mutations and nucleotide diversities in synonymous and non-synonymous sites as well as synonymous and non-synonymous substitution rates (Ks and Ka values) in COXI, cyt-b and 12S rRNA regions. Analyses showed that synonymous substitution rates are greater than non-synonymous substitution rates and it can be concluded that synonymous substitutions are more observed which don’t alter protein sequences, therefore selective pressure is negative on M. hartingi and M. lydius which have been considered same species by some authors.