Y. Karakousis

Genetic differentiation and phylogenetic relationships among Greek Salmo trutta L. (brown trout) populations as revealed by RFLP analysis of PCR amplified mitochondrial DNA segments.

The genetic differentiation and phylogenetic relationships of 13 populations (11 from Greece, one from Albania and one from France) of brown trout (Salmo trutta L.) were investigated at the mtDNA level. RFLP analysis of four segments of mitochondrial DNA (D-loop, cytochrome b and ND-5/6) amplified by PCR was used. Seven of 14 restriction endonucleases were found to detect variability in the ND-5/6 regions, whereas four and two out of 17 and 16 were polymorphic in the D-loop and cytochrome b, respectively. Eleven different haplotypes were observed. The observed interpopulation diversity was very high (mean = 1.65 per cent), whereas the intrapopulation diversity was low in most cases (mean = 0.063 per cent). Five phylogenetic assemblages were identified. The results demonstrate that Greece is one of the regions where brown trout display very high levels of genetic diversity. Most populations were genetically very distinct, possessing private mtDNA genotypes. Therefore, they represent unique gene pools which may warrant individual recognition for conservation and management. The genetic relationships among populations suggested by mtDNA data were not in accordance with allozyme data. This study illustrates the importance of considering the historical biogeography of a species in order to understand its population genetic structure. It also reinforces the view that mtDNA analysis represents a powerful tool to study past and present demographic phenomena.

Genetic divergence and phylogenetic relationships among Salmo trutta L. (brown trout) populations from Greece and other European countries

In order to clarify the genetic structure and the phylogenetic relationships among brown trout (Salmo trutta) populations from Greece and other European countries starch gel electrophoresis was used. The populations come from various rivers from Greece and other European countries, flowing to the Atlantic or to the Mediterranean. Eleven enzymic systems were investigated. These correspond to 26 putative loci. A high degree of genetic polymorphism was found. The percentage of polymorphic loci ranged from 3.8 to 34.6 and the degree of expected heterozygosity from 0.016 to 0.1. F-statistics and clustering analyses indicated the existence of a high degree of differentiation. This differentiation is mainly between the Atlantic and the Mediterranean populations. Furthermore the Mediterranean populations seem to be divided into two groups. One includes the western Mediterranean populations and populations from western Greece and the other north-eastern Greek populations. The latter seem to be related to other Balkan populations and probably to Danubian or Black Sea populations. These results support the idea of two different lineages of Mediterranean brown trout populations, one of which is probably of aboriginal origin.

Phylogenetic relationships of Barbus peloponnesius valenciennes, 1842 (Osteichthyes: Cyprinidae) from Greece and other species of Barbus as revealed by allozyme electrophoresis

Abstract The phylogenetic relationships among populations belonging to the species Barbus peloponnesius , a species from Greece with ambiguous taxonomic status and to other populations belonging to the species Barbus ( B. petenyi and B. meridionalis ) were investigated. A high degree of genetic similarity between B. peloponnesius and B. petenyi was revealed. In contrast, the former species seems to be genetically distinct from B. meridionalis . The possible influence of paleogeographic events on the phylogenetic relationships of these species is considered.

ALLOZYME VARIATION IN EUROPEAN SILURID CATFISHES, SILURUS GLANIS AND SILURUS ARISTOTELIS

Abstract The genetic structure and relationships of the two European catfish species, Silurus glanis (widely distributed in Europe) and Silurus aristotelis (endemic to Greece) were examined using 17 allozyme systems corresponding to 28 putative loci. The two species are well differentiated with fixed differences at five loci. Genetic distance values support inclusion of both species in the same genus. Average heterozygosities of 0.039 and 0.037 for native populations of the two species are slightly lower than previous average estimates for freshwater fishes. Greek S. glanis populations showed lower values of heterozygosity than the other European populations. A hypothesis for the evolution and dispersal of the two species is proposed, based on the estimated time of divergence and on the present distribution of these species.

Genetic polymorphism and differentiation among chub Leuciscus cephalus L. (Pisces, Cyprinidae) populations of Greece☆

Abstract To clarify the genetic structure of chub ( Leuciscus cephalus L.) populations, eleven enzymatic systems corresponding to 20 putative loci were investigated in 15 populations from different rivers throughout Greece and one sample from France. The proportion of polymorphic loci detected ranged from 5 to 45% and the degree of expected heterozygosity from 0.019 to 0.072. Phenograms constructed from the allozyme data were generally concordant with the recognition of four subspecies of L. cephalus . Values of genetic distance among the populations, however, do not justify this classification. The possible influence of paleogeographic events on the phylogenetic relationships of the putative subspecies is discussed.

Banded karyotype of the cyprinid fishLeuciscus borysthenicus

1Laboratory ofFish Genetics, Institute of Animal Physiology and Genetics, Academy of Sciences of the Czech Republic, 277 21 Libechov, Czech Republic (*e-mail: rab@site.cas.cz) 2Department of Genetics, Development and Molecular Biology, School of Biology, Faculty of Sciences, Aristotle University, GR-54006 Thessaloniki, Greece 3Department of Zoology, School of Biology, Faculty of Sciences, Aristotle University, GR 54006 Thessaloniki, Greece

Genetic and morphological differentiation among populations of the green toad Bufo viridis from Northern Greece

Abstract Studies of external morphology and allozymes in five populations of the green toad Bufo viridis , from northern Greece revealed a high degree of genetic variation. Average heterozygosity of the five populations was 0.14 and 47% of the loci were polymorphic. Discriminant analysis of morphological characters indicated that one population was significantly different from the rest. No correlation was found between the genetic distance and the Mahalanobis Distance, as calculated from morphological characters. These populations of B. viridis seem to have a similar genetic structure to the frogs Hyla arborea and Rana ridibunda , which also occur in the same area.