Major Histocompatibility Complex Class ⅡB Gene And Phylogeography Analysis Of Amji Salamander (Hynobius Amjiensis)

Amji salamander(Hynobius amjiensis) is a critically endangered species endemic to the China. Due to narrow-range distribution and small population sizes, this species is at risk of extinction. In this studies, MHC (Major histocompatibility complex)class ⅡB genes exon2、 cytochrome b、 recombination activating gene2 were chosed as molecular markers to study the genetic diversity, genetic structure, phylogenetic relationships, historical dynamics of Amji salamander. The results are shown as follows:(1) The low genetics diversity of H.amjiensis.MHC ⅡB dates、Cyt b dates、RAG2 dates shows low nucleotide diversity. All of this showsd that genetics diversity of H.amjiensis is very low, the genetics diversity levels are same as Andrias davidianus、 Nanorana parkeri、 Pachyhynobius shangchengensis.(2)"Sky Island" lead to significant population differentiation.A muti-locus data set consisting of Cyt b and RAG2 revealed exchanges between the three populations are not frequent and genetic differentiation is very high. Amji salamander only live in peat moss wetlands at an altitude higher than 1300m. Climatic and geological conditions in low altitude areas lead to isolation between 3 populations, formed "Sky Island".(3)The history population of H.amjiensis has occurred expansion.Qingliang mountain in Anhui province’s climate has influenced by Quaternary glaciation. AHQLF population is located in Anhui qingliang peak and has greatly influenced by Pleistocene last glacial. ZJQLF population and LWS population were relatively stable for a long time and haven’t experienced expansion.(4) Three populations of H.amjiensis are defined as two evolutionary significant unit (ESUs).Follow the principle of Conservation genetics, this study has developed two H.amjiensis protection unit, that is eastern LWS populations is a distinct evolutionary significant unit and western ZJQLF population and AHQLF population as a large evolutionary significant unit. Therefore, H.amjiensis as East and West two separate management units to carry out conservation work.