Genetic Diversity among Wild and Cultured Stocks of Sparus aurata on Turkish Mediterranean Coasts Revealed by Mitochondrial DNA Sequences

Abstract

The sequences of three mitochondrial DNA genes - 12S rRNA, cytochrome b, cytochrome oxidase II - were used to deduce genetic diversity and relationships among wild and cultured populations of gilthead sea bream (Sparus aurata) on Turkish coasts and coastal waters. The 415 bp of 12S rRNA, 605 bp of cytochrome oxidase II, and 557 bp of cytochrome b genes were sequenced and the data set was analyzed with Neighbor Joining and Minimum Evolution. Bootstrap analyses (1000 replicates) were performed and the relationships between samples are given in phylogenetic trees. Genetic diversity was estimated using gene diversity, number of haplotypes, and nucleotide diversity. There were no significant differences in variation in any of the three gene sequences. The maximum genetic variation occurred in cytochrome b (0.0050). Similarly, results showed very little divergence between sampling sites. Findings indicate a single wild population in the eastern Mediterranean, supporting the current classification that lacks subdivisions. Further, no differentiation between wild and culture stocks was inferred.