简介：ToinvestigategeneticmechanismsofhighaltitudeadaptationsofnativemammalsontheTibetanPlateau,wecomparedmitochondrialsequencesoftheendangeredPantholopshodgsoniiwithitslowlanddistantrelativesOvisariesandCaprahircus,aswellasothermammals.ThecompletemitochondrialgenomeofP.hodgsonii(16,498bp)revealedasimilargeneorderasofothermammals.Becauseoftandemduplications,thecontrolregionofP.hodgsoniimitochondrialgenomeisshorterthanthoseofO.ariesandC.hircus,butlongerthanthoseofBosspecies.PhylogeneticanalysisbasedonalignmentsoftheentirecytochromebgenessuggestedthatP.hodgsoniiismorecloselyrelatedtoO.ariesandC.hircus,ratherthantospeciesoftheAntilopinaesubfamily.TheestimateddivergencetimebetweenP.hodgsoniiandO.ariesisabout2.25millionyearsago.FurtheranalysisonnaturalselectionindicatedthattheCOXI(cytochromecoxidasesubunitI)genewasunderpositiveselectioninP.hodgsoniiandBosgrunniens.Consideringthesameclimatesandenvironmentssharedbythesetwomammalianspecies,weproposedthatthemitochondrialCOXIgeneisprobablyrelevantforthesenativemammalstoadaptthehighaltitudeenvironmentuniquetotheTibetanPlateau.