Divergent domain D11 of 28S rRNA gene as a molecular marker in the phylogenetic relationship study of some parrotfish species from the Egyptian Red Sea

Parrotfish is a ubiquitous and very varied group connected to coral reef ecosystems. A comparative genetic investigation was achieved using divergent domain D11 of 28S rRNA sequences in six parrotfish (Scarus ferrugineus, Scarus psittacus, Scarus frenatus, Chlorurus sordidus, Scarus ghobban and Cetoscarus bicolor) to manifest generic visibility about the phylogenetic linkages of those species. The sequenced regions of divergent domain D11 of 28S rRNA in six parrotfish species submitted in the GenBank/NCBI under accession numbers (MW144763 - MW144768). Length of nucleotide sequence, based on divergent domain D11 of 28S rRNA, ranged from 612 bp. to 616 bp. The average nucleotide
frequencies of adenine (A), thymine (T), cytosine (C) and guanine (G) were 21.9%, 23.8%, 23.1% and 31.2% respectively. The CG- contents were higher than that of AT- contents in all species. The average content of C+G was 3.45%. Genetic distance among parrotfish species ranged from 0.000% to 0.006%. Overall, the distance value among all fishes was 0.007%. Due to the limited data on phylogenetic inferences in parrotfish based on divergent domain D11 of 28S rRNA, the present study could be helpful in the detection of genetic relationships for parrotfish species using 28S rRNA gene marker.