Van Hooft, PimDougherty, Eric R.Getz, Wayne MarcusGreyling, Barend JacobusZwaan, Bas J.Bastos, Armanda D.S.2018-03-282018-03-282018-02-07Van Hooft P, Dougherty ER, Getz WM, Greyling BJ, Zwaan BJ, Bastos ADS (2018) Genetic responsiveness of African buffalo to environmental stressors: A role for epigenetics in balancing autosomal and sex chromosome interactions? PLoS ONE 13(2): e0191481. https://DOI.org/ 10.1371/journal.pone.0191481.1932-6203 (online)10.1371/journal.pone.0191481http://hdl.handle.net/2263/64327S1 Fig. Map with locations of the rainfall stations and the sampled herds.S2 Fig. Regression between fraction HBC among BTB-negative females and BTB prevalence per herd.S1 Table. Logistic regression southern females with body condition status as dependent variable (highest ranking model).S2 Table. Logistic regression southern males with body condition status as dependent variable (highest ranking model).S3 Table. Logistic regression southern females with BTB status as dependent variable (highest ranking model).S4 Table. Logistic regression southern males with BTB status as dependent variable (highest ranking model).S5 Table. Logistic regression northern females with body condition status as dependent variable (highest ranking model).S6 Table. Logistic regression southern males with BTB status as dependent variable (Evidence Ratio = 1.9).S7 Table. Logistic regression northern males with body condition status as dependent variable (Evidence Ratio = 2.1).S8 Table. Significance of the genetic-measure by annual-rainfall interaction per single year.S9 Table. Logistic regression northern females with body condition status as dependent variable (Evidence Ratio = 1.8).S10 Table. Results Hedges' g analyses (group differences with respect to MDLmale and MDLfemale).S1 Text. Consistency of the model outcomes.In the African buffalo (Syncerus caffer) population of the Kruger National Park (South Africa) a primary sex-ratio distorter and a primary sex-ratio suppressor have been shown to occur on the Y chromosome. A subsequent autosomal microsatellite study indicated that two types of deleterious alleles with a negative effect on male body condition, but a positive effect on relative fitness when averaged across sexes and generations, occur genome-wide and at high frequencies in the same population. One type negatively affects body condition of both sexes, while the other acts antagonistically: it negatively affects male but positively affects female body condition. Here we show that high frequencies of male-deleterious alleles are attributable to Y-chromosomal distorter-suppressor pair activity and that these alleles are suppressed in individuals born after three dry pre-birth years, likely through epigenetic modification. Epigenetic suppression was indicated by statistical interactions between pre-birth rainfall, a proxy for parental body condition, and the phenotypic effect of homozygosity/heterozygosity status of microsatellites linked to male-deleterious alleles, while a role for the Y-chromosomal distortersuppressor pair was indicated by between-sex genetic differences among pre-dispersal calves. We argue that suppression of male-deleterious alleles results in negative frequencydependent selection of the Y distorter and suppressor; a prerequisite for a stable polymorphism of the Y distorter-suppressor pair. The Y distorter seems to be responsible for positive selection of male-deleterious alleles during resource-rich periods and the Y suppressor for positive selection of these alleles during resource-poor periods. Male-deleterious alleles were also associated with susceptibility to bovine tuberculosis, indicating that Kruger buffalo are sensitive to stressors such as diseases and droughts. We anticipate that future genetic studies on African buffalo will provide important new insights into gene fitness and epigenetic modification in the context of sex-ratio distortion and infectious disease dynamics.en© 2018 van Hooft et al. This is an open access article distributed under the terms of the Creative Commons Attribution License,Infectious diseaseAfrican buffalo (Syncerus caffer)Kruger National Park (KNP)Kruger National Park (South Africa)Sex-ratio distortionBovine tuberculosis (bTB)Article