ABSTRACT
In this study, mitochondrial DNA analysis using 16S ribosomal DNA [rDNA] was performed to investigate the phylogeny relationship of Trichiurus lepturus in the Persian Gulf compared to the other investigated area. The amplification of 16S rDNA resulted in a product of 600 bp in all samples. The results showed that the isolated strain belongs to T. lepturus showing 42 divergence sites among the same reported partial sequences of 16S rRNA gene from the other area [West Atlantic and Indo-Pacific area]. Phylogeny results showed that all 18 haplotypes of the species clustered into five clades with reasonably high bootstrap support of values [>64%]. Overall, the tree topology for both phylogenetic and phenetic trees for 16S rDNA was similar. Both trees exposed two major clusters, one wholly containing the haplotypes of the T. lepturus species belonging to Indo-Pacific area with two major sister groups including Persian Gulf specimen and the other cleared the Western Atlantic and Japan individuals clustered in another distinct clade supporting the differentiation between the two areas. Phylogenic relationship observed between the Persian Gulf and the other Indo-Pacific Individuals suggested homogeneity between two mentioned areas
ABSTRACT
Molecular investigation of important commercial shrimp species is one of the main goals to find out the pure populations and brood stocking of marine resources. The purpose of the present study was to study the population of P. merguiensis and determining the extent of genetic diversity of this species. Samples were collected from three major distribution areas in the Persian Gulf and Oman Sea. Molecular investigation was carried out using microsatellite markers. Only five out of the eight primers of P. merguiensis produced good amplified PCR products with fixed annealing temperature. The rest of the primers were either not easily amplified or produced nonspecific bands. Seven alleles were found to be unique to each of the three populations of P.merguiensis. Occurrences of heterozygosity deficiency were found at most loci. These heterozygosity deficiencies in observed heterozygosity in comparison to expected heterozygosity may be due to inbreeding, genetic drift and consequences of illegal overharvesting of P. merguiensis in the studied areas as well. Deviation from Hardy-Weinberg Equilibrium in both studied species was significant in most microsatellite loci [p<0.001]. We observed deviation from HWE in most loci with hetrozygosity deficits. The genetic variation results showed that the pairwise Fst values were significant between studied populations. The assignment test revealed high gene flow between Hormoz and Jask and restricted genetic flow between Guatr and Hormoz populations. It seems that the changes in immigration patterns of populations between Hormoz, Jask and Guatr areas depend on the influence of Persian Gulf currents or the life cycle of P. merguiensis in studied areas. Alternatively, the presence of ecological barriers such as mangrove forests may result in restricted genetic flow between Guatr and both Hormoz and Jask populations