Same-sex mounts provide male juvenile golden snub-nosed monkeys(Rhinopithecus roxellana)with opportunities to practice heterosexual copulatory skills and are often followed by grooming(post-mounting grooming,PMG).We hypothesized that juveniles acted as the mountee and provided mounting opportunities to receive grooming from their peer mounter.Here,we observed same-sex mounts among male juveniles(N=5)in a captive group of R.roxellana in Shanghai Wild Animal Park,China,from November 2014 to June 2015.Among 1,044 mounts recorded,45.40% were accompanied by PMG initiated by the mounter and only 3.74% were followed by PMG initiated by the mountee.Mountees were more likely to receive PMG when they performed a mounting solicitation than when they did not,or when they were mounted for a longer time(even if they did not solicit).Over a long timeframe(1 month),mountee’s tended to choose partners who groomed them more often than others after mounting,regardless of how long the grooming lasted.However,whether the mounter groomed the mountee did not predict the mounting direction in their subsequent mount.Our results suggest that,in the context of same-sex mounts,juveniles provide mounting opportunities to receive grooming from peers on a long-term,rather than on a short-term basis.This study provides the first evidence that juveniles’same-sex mounting strategy may be associated with the grooming market in nonhuman primates,which necessitates further investigation with large free-ranging groups due to the limited sample size of individuals and the captive setting of the current study.
DNA methylation plays a crucial role in environmental adaptations.Here,using whole-genome bisulfite sequencing,we generated comprehensive genome-wide DNA methylation profiles for the high-altitude Yunnan snub-nosed monkey(Rhinopithecus bieti)and the closely related golden snub-nosed monkey(R.roxellana).Our findings indicated a slight increase in overall DNA methylation levels in golden snub-nosed monkeys compared to Yunnan snub-nosed monkeys,suggesting a higher prevalence of hypermethylated genomic regions in the former.Comparative genomic methylation analysis demonstrated that genes associated with differentially methylated regions were involved in membrane fusion,vesicular formation and trafficking,hemoglobin function,cell cycle regulation,and neuronal differentiation.These results suggest that the high-altitude-related epigenetic modifications are extensive,involving a complete adaptation process from the inhibition of single Ca^(2+)channel proteins to multiple proteins collaboratively enhancing vesicular function or inhibiting cell differentiation and proliferation.Functional assays demonstrated that overexpression or down-regulation of candidate genes,such as SNX10,TIMELESS,and CACYBP,influenced cell viability under stress conditions.Overall,this research suggests that comparing DNA methylation across closely related species can identify novel candidate genomic regions and genes associated with local adaptations,thereby deepening our understanding of the mechanisms underlying environmental adaptations.
Ling WangWei-Qiang LiuJuan DuMeng LiRui-Feng WuMing Li
川金丝猴(Rhinopithecus roxellana)是旧大陆猴,隶属于猴科(Cercopithecidae)疣猴亚科(Colobinae)仰鼻猴属(Rhinopithecus),是我国特有的三种金丝猴之一(向左甫,2020)。尽管川金丝猴交配行为全年存在,但出生却表现明显季节性特点(Xiang et al.,2017;陆展滔等,2024)。研究表明,季节性繁殖的灵长类动物猕猴(Macaca mulatta)(Waitt et al.,2003)和滇金丝猴(Rhinopithecus bieti)(Grueter et al.,2015)面部颜色均具有季节性变化。
动植物关系是生态学研究的热点,而种子传播是研究食果动物与植物之间互作关系和协同进化关系的途径(Lambert and Garber,1998;Fleming and Kress,2011;Arroyo-Rodriguez et al.,2015)。鸟类、翼手目和灵长类等食果动物是植物种子的主要传播者(Leighton,1993;Martins,2006;Fleming and Kress,2011;李宁等,2021),种子传播具有促进森林生态系统更新、群落物种生物多样性的维系及植物种群延续等生态功能(Howe and Smallwood,1982;Jordano,2014;Yao et al.,2021)。
Small and isolated populations face several intrinsic risks,such as genetic drift,inbreeding depression,and reduced gene fow.Thus,patterns of genetic diversity and differentiation have become an important focus of conservation genetics research.The golden snub-nosed monkey Rhinopithecus roxellana,an endangered species endemic to China,has experienced rapid reduction in population size and severe population fragmentation over the past few decades.We measured the patterns of genetic diversity and population differentiation using both neutral microsatellites and adaptive major histocompatibility complex(MHC)genes in 2 R.roxellana populations(DPY and GNG)distributed on the northern and southern slopes of the Qinling Mountains,respectively.Eight MHC-linked haplotypes formed by 5 DQA1 alleles,5 DQB1 alleles,5 DRB1 alleles,and 4 DRB2 alleles were detected in the 2 populations.The larger GNG population showed higher genetic variation for both MHC and microsatellites than the smaller DPY population,suggesting an effect of genetic drift on genetic variation.Genetic differentiation index(FST)outlier analyses,principal coordinate analysis(PCoA),and inferred population genetic structure showed lower genetic differentiation in the MHC variations than microsatellites,suggesting that pathogen-mediated balancing selection,rather than local adaptation,homogenized the MHC genes of both populations.This study indicates that both balancing selection and genetic drift may shape genetic variation and differentiation in small and fragmented populations.
