Sequencing And Phylogenetic Analysis Of Mitochondrial Genes From Three Species Of Abalone

The mitochondrial 16S rRNA,CO ? and CO ? genes are the most common gene sequences in the study of mitochondrial gene.They are widely used in population genetic structure,phylogenetic relationship and genetic relationship among populations.They are relatively faithful molecular markers.In this paper,H.discus hannai from China,H.rubra from Australia and H.iris from New Zealand were selected as the samples of the study.By sequencing The mitochondrial 16S rRNA,CO ?,CO ? genes,to analyze its single nucleotide polymorphisms and interspecies identity and phylogenetic relationship.The result will help abalone hybrid breeding in abalone aquaculture industry.The main contents of this study are divided into the following three parts:(1)?Sequencing and phylogenetic analysis of mitochondrial 16S rRNA gene fragments of three abaloneThe 16S rRNA gene fragments of H.discus hannai,H.iris and H.rubra were amplified and sequenced by gene sequencing.The results showed that the sequence length was 544bp,150bp and 466bp,respectively.The contents of A + T were 58.1%,56.2%and 56.4%,respectively.The identity was 96.37%,97.51%,and 99.06%,respectively.The species identity among the three species was 93.94%.The base mutation rates of H.discus hannai,H.iris and H.rubra are 0.37%,0.55%and 0.36%.The genetic distance between H.iris and H.rubra is 0.148,and the genetic distance between H.discus hannai and the H.rubra was 0.116,and the genetic distance between H.discus hannai and the H.iris was 0.077.(2)?Sequencing and phylogenetic analysis of mitochondrial CO ? gene fragments of three abaloneThe sequence of mitochondrial CO ? gene of of H.discus hannai,H.iris and H.rubra were amplified and sequenced by gene sequencing.The results showed that the sequence length was 554bp,553bp,552bp,respectively.The contents of A + T were 55.4%,52.3%,53.5%,respectively.The identity was 97.66%of H.discus hannai,98.49%of H.rubra,and 97.42%of H.iris.The species identity among the three species was 89.12%.The base mutation rates of H.discus hannai,H.iris and H.rubra are 0.36%,0.36%and 2,09%.The genetic distance between H,iris and H.rubra is 0.204,and the genetic distance between H.discus hannai and the H.rubra was 0.200,and the genetic distance between H.discus hannai and the H.iris was 0.186.(3).Sequencing and phylogenetic analysis of mitochondrial CO ? gene fragments of three abalonesThe sequence of mitochondrial CO II gene of of H.discus hannai,H.iris and H.rubra were amplified and sequenced by gene sequencing.The results showed that the sequences length was 151bp,150bp and 153bp respectively.The contents of A + T was 58.3%,53.7%and 56.5%,,respectively.The intraspecific identity was 98.23%,99.33%and 91.83%,respectively.The species identity among the three species was 92.51%.The base mutation rates of H.discus hannai,H.iris and H.rubra are 3.31%,19.61%and 2.00%.The genetic distance between H.iris and H.rubra is 0.124,and the genetic distance between H.discus hannai and the H.rubra was 0.192,and the genetic distance between H.discus hannai and the H.iris was 0.071.The results show that the mitochondrial 16S rRNA,CO ? and CO ? gene fragments are suitable for the genetic analysis,phylogenetic and phylogenetic relationships among abalones.The data showed that the 16S rRNA sequence of mitochondria was the most conserved and the mutation rate of CO ? gene was the highest.The relationship between H.discus hannai and H.iris is similar.The relationships among abalones belonging to the same geographical population is close.