Biochemical systematics and evolution of Myoxidae

Abstract

Genetic variation and divergence were analysed among 43 popu- lations representing the five western Palaearctic genera of the family Myoxidae: Myoxus, Myomimus, Muscardinus, Eliomys and Dryomys. Intraspecific and interspecific genetic divergence were evaluated by electrophoretic analysis of 3 8-42 gene loci and compared with data from fossil records. The mean values of heterozygosity per locus for each species ranged from 0.024 in Myomimus roachi to 0.062 in Dtyomys nitedula. The mean values of intraspecific genetic distance ranged from 0.04 in Dryomys nitedula to 0.081 in Eliomys melanurus. A comparison of the five genera, based on 38 gene loci indicated a high level of differentiation. Only two loci were found monomorphic and fixed for the same allele in the five genera: Ldh-2 and Got-2. The lowest mean value of genetic distance was observed between the genera Myoxus and Eliomys (D = 1.283). Muscardinus displayed a higher value of genetic distance in comparison with Myoxus and Eliomys (D = 1.629). The highest mean value of genetic distance was displayed by these three genera in comparison with Mj~omimus and Dryomys (D = 2.25 1). A high value of genetic distance was also observed between Myomimus and Dryomys: D = 1.811. These values are in agreement with the ancient origin of this family, that had its highest expansion and diversification during the Miocene.