Structural Characteristics Of Mitochondrial Genome And Preliminary Phylogenetic Analysis For Lepus Hainanus

We sequenced the complete mitochondrial (mt) genome of Lepus hainanus by polymerase chain reaction. Characteristies of mitochondrial gneome of L. hainanus are summarized as following. The complete mt genome has16939base pairs in length and included37genes, i.e.,13protein-coding genes (PCGs),22tRNA, and2rRNA, and a non-coding control region. The H strand of mitochondrial genome consists of31.6%A,26.1%C,13.5%G, and29.0%T bases, showing a compositional bias. Adenines were preferentially used in third codon positions of PCGs. However, there was an anti-G bias in third codon positions. Our results showed that all Ka/Ks ratios were well less than1, indicating that purifying selection was the predominant force in mtDNA evolution. ATG was used as a start codon for all of the PCGs, with the exceptions of ND2and ND5, which started with ATT. The most favourite stop codon was TAA which was used by six PCGs. However, ND1, COX2, ND6ended on TAG, COB ended on AGG, ND3and COX3ended on TA, ND4ended on an incomplete stop codon T.Phylogenetic relationships of23Lepus species were determined by analysing187cyt b complete gene sequences using neighbor-joining method and maximum likehood method. The results show the preliminary relationship among the23Lepus species and there is introgressive hybridization among most of these hares. The present results provided some new insights into the tangled phylogenetic relationships of Lepus.