Mitochondrial DNA variation in wild and hatchery populations of northern pike, Esox lucius L.

Esox lucius is an economically important freshwater species. Mitochondrial cytb, ۱۲SrRNA, and ۱۶SrRNA gene sequences were used in order to clarify the genetic variation and population structure in three E. Lucius populations, i.e., one Wild population (W) and two hatchery populations (Hatchery Population I-HPI and Hatchery Population II-HPII). A total of ۵۵ individuals, with ۱۹ from wild and ۱۸ from each hatchery population, were sequenced. The results are as follows: ۱) cytb. Eleven variable sites defined eight distinct haplotypes, with ۱۱۳۷ base pairs (bp) complete cytb sequences. The nucleotide diversity (π) values were W ۰.۰۰۹%, HPI ۰.۰۷۵% and HPII ۰.۰۶۸%, respectively. Genetic distances within and between populations were both between ۰ and ۰.۱%. Analysis of molecular variance (AMOVA) analysis revealed that variation within populations accounts for ۹۸.۴۹% of total variation. ۲) ۱۲SrRNA. We obtained ۳۸۰ bp consensus ۱۲SrRNA sequence and found little variation among the ۵۵ sequences. ۳) ۱۶SrRNA. Twelve variable sites defined seven haplotypes, with ۵۱۹ bp consensus ۱۶SrRNA sequence. The π values were W ۰.۰۴۱%, HPI ۰.۳۱۰% and HPII ۰.۰۲۱%, respectively. Genetic distances were between ۰ and ۰.۳% within populations and from ۰ to ۰.۲% between populations. AMOVA disclosed that variation within populations accounts for ۹۱.۷۹% of total variation. Variation within populations is the main source of total variation. The results suggest that low genetic variation can be found in both wild and hatchery populations of E. lucius, and the effect of genetic drift and adaptation to culture conditions gradually emerged under only two generations’ artificial cultivation.

کلیدواژه ها:

Esox lucius ، mitochondrial DNA ، genetic diversity ، genetic variability ، hatchery