Population genetic studies of Liza aurata using D-Loop sequencing in the southeast and southwest coasts of the Caspian Sea

Genetic diversity as an important marker of the ecological status of aquatic ecosystems is considered a unique and powerful tool to evaluate biological communities. In order to evaluate the genetic diversity among golden mullet species (Liza aurata) in the southeast and southwest coasts of the Caspian Sea by D-Loop gene sequencing, a total of 23 fin specimens of golden mullet were collected from the Gilan (Anzali area) and Golestan (Gomishan area) provinces. Total DNA from the samples was extracted by ammonium acetate method and the quality and quantity of the extracted DNA were assessed by spectrophotometery and electrophoresis. Polymerase Chain Reaction (PCR) was conducted on the target DNA and then DNA sequencing was carried out. D- loop region in mitochondrial DNA (mtDNA) of golden mullet contained 900 base pairs (bp). Phylogenetic relationships among golden mullet were calculated by MEGA software version 5.05 and divergence time was estimated using Tahjima's test. The results obtained from this study revealed that there were high genetic differences among two regions in the Gilan and Golestan provinces. Kimura 2-parameter was used for genetic distance analysis and the genetic distance recorded between Gilan and Golestan Provinces was calculated at 0.259. The high levels of FsT were observed between Gilan and Golestan Provinces which indicates that genetic differences exist among present populations (p≤.05). Based on the results obtained from the south Caspian Sea, probably two different populations of Liza aurata are living in the Gilan and Golestan Provinces.