Female Mate Choice Based On MHC And Microsatellite In Golden Snub-nosed Monkeys(Rhinopithecus Roxellana)

Mate choice is the central subject of sexual selection research.It also play an important role in animal's fitness.Females carefully choose their mates to obtain direct benefits such as food and territories,or obtain indirect genetic benefits through their offspring.There are four hypotheses about the indirect benefits of mate choice:choice for good genes,choice for heterozygosity,disassortative choice and inbreeding avoidance hypothesis.The golden snub-nosed monkey(Rhinopithecus roxellana)is an endangered and rare peculiar animal in China.It's characterized by large multilevel societies(MLS)comprised of one-male unit(OMU)and all-male unit(AMU).Despite all the adult females were socially exclusively attached to one resident male,they have been observed to transfer between familial units(“divorce and remate”).Moreover,as all the resident male would be ultimately taken over by a new adult male,the female may conduct a significant influence on the outcome of a male-male combat for takeover of a familial unit.In addition,extra-unit copulation was frequently observed in the field and more than half of the offspring were sired by extra-unit males in this population.However,the criteria for females to evaluate males and the reasons for females choosing extra-unit males in golden snub-nosed monkey are still unclear.In this study,MHC class II DPB1 and microsatellite locus were used to assess the genetic diversity of the golden snub-nosed monkey and to analyze female's genetic preference for mate choice in the West Ridge Troop(WRT)of in Qinling Mountains.The main results are as follows:1.In the study troop,both diversity and heterozygosity were high at microsatellite loci(PIC>0.5,H_O>0.5).Meanwhile,we found moderate genetic diversity(0.25<PIC<0.5)and low heterozygosity(H_O<0.5)at DPB1 locus.2.We found that females mate choice consistent with benefits to offspring via DPB1 locus rather than microsatellites.3.Females tend to choose males possess DPB1~*02,or heterozygote or high MHC diversity as their social males and genetic males.However,they avoid choosing genetic males possess DPB1~*04(P<0.05).There's no evidence about significant differences between extra-unit social males and extra-unit genetic fathers at DPB1locus(P>0.05).However,intra-unit social males have higher DPB1~*02,heterozygosity and individual MHC diversity than extra-unit males(P<0.05).In summary,in the golden snub-nosed monkey population of this study,there is no evidence of female mate choice at the microsatellite locus,but females prefer to choose males with good genes and heterozygosity in the DPB1 locus as social males and genetic males.When social males with good genes,heterozygosity and higher MHC diversity,females in their units less copulated mate with other males.The results are helpful for the protection and management of captive snub-nosed monkeys.