Rainfall-driven sex-ratio genes in African buffalo suggested by correlations between Y-chromosomal haplotype frequencies and foetal sex ratio

BMC Evolutionary Biology

Research Article

Paul D van Helden¹  Anna E Jolles²  Armanda DS Bastos³  Barend J Greyling⁴  Wayne M Getz⁵  Herbert HT Prins⁶  Sipke E van Wieren⁶  Pim van Hooft⁷ 

[1] DST/NRF Centre of Excellence for Biomedical TB Research, US/MRC Centre for Molecular and Cellular Biology, Division of Molecular Biology and Human Genetics, Faculty of Health Sciences, Stellenbosch University, 7505, Tygerberg, South Africa;Department of Biomedical Sciences, College of Veterinary Medicine, Oregon State University, 97331, Corvallis, OR, USA;Mammal Research Institute, Department of Zoology & Entomology, University of Pretoria, 0002, Pretoria, South Africa;Mammal Research Institute, Department of Zoology & Entomology, University of Pretoria, 0002, Pretoria, South Africa;Agricultural Research Council, 0062, Irene, South Africa;Mammal Research Institute, Department of Zoology & Entomology, University of Pretoria, 0002, Pretoria, South Africa;Department of Environmental Science Policy & Management, University of California at Berkeley, 140 Mulford Hall, 94720-3112, CA, USA;Resource Ecology Group, Wageningen University, Droevendaalsesteeg 3a, 6708, Wageningen, PB, The Netherlands;Resource Ecology Group, Wageningen University, Droevendaalsesteeg 3a, 6708, Wageningen, PB, The Netherlands;Mammal Research Institute, Department of Zoology & Entomology, University of Pretoria, 0002, Pretoria, South Africa;

关键词: Normalize Difference Vegetation Index;    Pregnancy Loss;    Semen Quality;    Kruger National Park;    African Buffalo;   

DOI  :  10.1186/1471-2148-10-106

 received in 2009-12-17, accepted in 2010-04-23,  发布年份 2010

来源: Springer

【 摘 要 】

BackgroundThe Y-chromosomal diversity in the African buffalo (Syncerus caffer) population of Kruger National Park (KNP) is characterized by rainfall-driven haplotype frequency shifts between year cohorts. Stable Y-chromosomal polymorphism is difficult to reconcile with haplotype frequency variations without assuming frequency-dependent selection or specific interactions in the population dynamics of X- and Y-chromosomal genes, since otherwise the fittest haplotype would inevitably sweep to fixation. Stable Y-chromosomal polymorphism due one of these factors only seems possible when there are Y-chromosomal distorters of an equal sex ratio, which act by negatively affecting X-gametes, or Y-chromosomal suppressors of a female-biased sex ratio. These sex-ratio (SR) genes modify (suppress) gamete transmission in their own favour at a fitness cost, allowing for stable polymorphism.ResultsHere we show temporal correlations between Y-chromosomal haplotype frequencies and foetal sex ratios in the KNP buffalo population, suggesting SR genes. Frequencies varied by a factor of five; too high to be alternatively explained by Y-chromosomal effects on pregnancy loss. Sex ratios were male-biased during wet and female-biased during dry periods (male proportion: 0.47-0.53), seasonally and annually. Both wet and dry periods were associated with a specific haplotype indicating a SR distorter and SR suppressor, respectively.ConclusionsThe distinctive properties suggested for explaining Y-chromosomal polymorphism in African buffalo may not be restricted to this species alone. SR genes may play a broader and largely overlooked role in mammalian sex-ratio variation.

【 授权许可】

CC BY   
© van Hooft et al; licensee BioMed Central Ltd. 2010