Study on Morphological and Genetical Variation of Floatin Artemia cysts from Upper and Bottom Layers on Urmia Lake

Abstract

This investigation was carried out in order to study of Morphological and genetical difference of various cysts, identification of different ganetical populations and possibility of strains among populations. After assessing the density of cysts at certain interval from different layers of Urmia Lake, isolation of cysts from superficial and depth surfaces with salinity of 170ppt were done. Then, cysts from three stations isolated with sensitive devices. For studying of quality and slightly quantity of cysts, hatching percentage and biometry of cysts were carried out. DNA extraction with using phenol chloroform method from 210 samples of Artemia hatched were done. Population differences of floating cysts of Artemia urmiana were done by analyzing the results of RFLP of Ribosomal RNA (rRNA) gene, which is on mtDNA, was amplified by PCR techniques. In order to enzymatic digestion of PCR products by eleven enzymes Alu I, EcoR I, ECO47 I, Hae III, Hind III, Hinf I, Mbo I, Msp I, Rsa I, Taq I, Tru I were used. Two haplotype (AAAA, ABAA) showed similarity between cysts in those regions. To investigate the results Reap software and X2 test were used. The average of nucleotide diversity and haplotype diversity with in population were 0.006547±0.000003 and 0.5419±0.00292 and nucleotide divergence is estimated to be %0.0228. Based on the results, distribution of haplotypes in different geographical regions of Urmia Lake showed a notable difference and indicating genetical diversity in the Artemia stocks. Finally, investigation in the produced genotypes showed that PCR-RFLP technique with using Hinf I as a molecular marker can be use to separate the Artemia orumiana cysts in Urmia lake.