Genetic variation in the narrow-clawed crayfish (Astacus leptodactylus) populations as assessed by PCR-RFLP of mitochondrial COI gene

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The genetic variation and population structure of narrow-clawed crayfish (Astacus leptodactylus) was examined by means of polymerase chain reaction (PCR) restriction fragment length polymorphism (RFLP) analysis of the cytochrome oxidase subunit I (COI) of mitochondrial DNA. A total of 194 adult specimens were collected from seven sample sites including, two in the south Caspian Sea and one each in Anzali wetland and Aras reservoir and three rivers Chafrood, Masule Rudkhan and Siah Darvishan. The PCR products were digested with 19 restriction enzymes and five enzymes revealed polymorphism patterns (DdeІ, MboІ, TaqI, RsaІ and HinfІ). Twenty eight composite haplotypes were showed with the number of haplotypes in each population sample ranging from 8 to 13. Private haplotypes were found at very low frequencies. Two regional (Siah Darvishan River and Astara) groups were clearly recognized by cluster and molecular variance model (AMOVA) analyses (P<0.0001). Each of these groups revealed dominant haplotypes while these haplotypes play less important rule in population structures of the other geographic areas. Intrapopulation haplotype (h) and nucleotide (π) diversities were high for each locality, ranging h=0.7560±0.030 and π= 0.00334±0.00301, respectively. Results of this study discerned two genetically divergent populations of narrow-clawed crayfish including Siah Darvishan River and Astara. Thus, the population structure of the narrow-clawed crayfish, as inferred from mtDNA analysis, is constituted by genetically separate groups that nearly reflect their geographic distribution.