The Study On Mitochondrial Genome And Phylogenetic Analysis Of Sea Urchin(temnopleuridae Reevesii&Temnopleurus Hardwickiius)

In this study, the analysis of mtDNA genome of Temnopleurus reevesii&Temnopleurus hardwickiius were conducted, the phylogenetic relationship among9species of sea urchins and their relatives was also discussed,we will enrich the mtgenome database of world sea urchin, finally will provide useful information on thegenetics diversity protection of Temnopleuridae.Using27pairs of primers (10pairs for checking), we dermined themitochondrial genome of TemnopleurTemnopleurus reevesii&Temnopleurushardwickiius, in which process long PCR and regular PCR technologies wereemployed. The mitogenome lengths of Temnopleurus reevesii&Temnopleurushardwickiius are15696bp and15710bp, respectively. The two complete sequencesshare the similar strcture with the published mt genomes of vertebrate, both contain22transfer RNAs, two ribosomal RNAs,13protein coding genes and noncodingregion, whose arrangements follow the universial pattern in most Echinodermata. Thenucleotide composition shows a nucleotide bias against AT and especially in the tRNAin both sequences. As in other Echinodermata, most of the mitochondrial proteincoding genes take ATG as start codons except ATP8(GTG),ND4(ND4) inTemnopleurus reevesii and ATP8(GTG) ATP6(GTG) in Temnopleurushardwickiius.The usage of teiminal codons showed the same pattern between twokinds of sea urchin. The Temnopleurus reevesii individual exists the same lengths inthe two rRNA with Temnopleurus hardwickiiu individual. The origin of light strand replication can form the steady secondary structure in the two sequences.Concatenated protein-coding genes, concatenated tRNAs genes, concatenatedrRNAs genes and complete sequence were used respectively to construct phylogenetictrees of9species of Echinoidea and their relatives,calculate genetic distance withKimura-2-parameter The results showed the phylogenetic Tree structure of9species isconsistent with the morphological classification.