Molecular Identification and Phylogenetic Analysis of zoantharians based on ITS- rDNA marker in Larak Island, the Persian Gulf

The order Zoantharia (zoantharian) is a group of benthic Cnidarians which is widely distributed in coral reef ecosystems of the Persian Gulf. In the present study for the first time the nuclear marker (ITS-rDNA) was used to examine the diversity of zoantharians in the Persian Gulf. Fifteen colonies, collected off Larak Island, were received from Marine Biology laboratory of Science and Research Branch-IAU. Bio Basic INC kit was used for DNA extraction and ITS-rDNA gene was amplified using zoantharian specific primers. Subsequently, all PCR products were sequenced. The data analysis was conducted using MEGA5 and MrBayes. Molecular phylogeny, using nuclear DNA marker, confirmed the presence of three zoantharian species in this region including Zoanthus sansibaricus, Palythoa aff. mutuki and Palythoa tuberculosa. The results of this study were consistent with the previous phylogenetic studies based on mitochondrial DNA markers. ITS-rDNA is not a highly conserved region and has multiple intragenomic variants therefore could not be used as a DNA barcode. However, using this nuclear marker can confirm the results of conservative mitochondrial marker. The obtained sequences during the present study showed considerable differences with previously reported sequences from all over the world. It might be concluded that the ecological conditions of the Persian Gulf may have caused gene mutation which should be further investigated.