genetic characterization of garra rufa (heckel, 1843) populations in tigris basin, iran using microsatellite markers

the isolation-by-distance theory states that the genetic differentiation between individuals raised by increasing geographic distance. therefore, this study tested this hypothesis for garra rufa , a freshwater fish species of iranian inland waters, from six rivers located at the different distances in tirgis basin. for this purpose, eight variable microsatellite loci were applied to identify geographic-based population structure of g. rufa . from 240 fish of six populations, 102 alleles were found with a mean number of 11.625 to 13.250 alleles. heterozygosity was ranged 0.567-0.638 in six studied populations. moreover, a significant deviations from hardy-weinberg were found in the studied populations. unweight pair group analysis indicated that the six studied populations could be divided into four major clusters. the results revealed a fairly high level of genetic variation in the microsatellite loci within six studied populations. wright’s fixation index (fst) ranged between 0.013-0.044 indicating little genetic differentiation between populations. within this range, however, we found a strong positive relation between fst and geographical distance lending support to the isolation-by-distance theory.