Genetic differentiation and phylogenetic relationships among Greek chub Leuciscus cephalus L (Pisces, Cyprinidae) populations as revealed by RFLP analysis of mitochondrial DNA

The phylogenetic and systematic relationships among 12 populations of Greek chub (Leuciscus cephalus L.) were investigated using RFLP analysis of two PCR-amplified mtDNA segments (D-loop and cytochrome b). Three out of eight, and nine out of ten restriction enzymes were polymorphic for D-loop and cytochrome b, respectively. Twenty-one different haplotypes were detected. Estimated nucleotide sequence divergence among the 21 genotypes ranged from 0.313 to 6.79%; the mean value of sequence divergence among populations was 3.421 +/- 0.00%. The calculated N-ST value of 0.94, indicates high interpopulation diversity. Dendrograms based on haplotypes as well as those of populations, support the previous recognition of different subspecies, but these mtDNA data are not concordant with previous allozyme data among these fish. Our results suggest that to clarify phylogenetic relationships multiple genetic systems need to be examined. (C) 1998 Elsevier Science Ltd. All rights reserved.