Aarnink A, Bonhomme M, Blancher A
Laboratoire d'Immunogénétique Moléculaire, EA 3034, Faculté de Médecine Purpan, Université Paul Sabatier, Toulouse 3, France.
Tissue Antigens. 2013 Jan;81(1):12-8. doi: 10.1111/tan.12028. Epub 2012 Nov 8.
The cynomolgus macaque (Macaca fascicularis) is a model of choice among primates for the study of local adaptation processes because of its mixed and wide insular and continental distribution. In a previous study, by using 12 markers [5 microsatellites located in the major histocompatibility complex (MHC) region and 7 outside MHC], we have detected a signal of positive selection on the microsatellite DRACA located inside the gene DRA. In order to refine the location of this signal of positive selection in the MHC region, we studied the genetic diversity of 36 markers (18 microsatellites spread across the MHC region and 18 autosomal microsatellites outside MHC) in a sample of 254 individuals from four populations (Vietnam, Java, the Philippines, and Mauritius). We estimated for each locus the deviation of F(st) from a neutral model by using two methods based on contrasted demographic models. The two approaches showed a signal of positive selection in the MHC class III region that is much more significant than the one previously reported for the marker DRACA which could have been influenced by a hitchhiking effect due to its proximity with the class III region.
食蟹猴（猕猴）因其混合且广泛的岛屿和大陆分布，是灵长类动物中研究局部适应过程的首选模型。在先前的一项研究中，我们使用12个标记（位于主要组织相容性复合体（MHC）区域的5个微卫星和MHC区域外的7个微卫星），在基因DRA内的微卫星DRACA上检测到正选择信号。为了细化MHC区域中正选择信号的位置，我们研究了来自四个种群（越南、爪哇、菲律宾和毛里求斯）的254个个体样本中36个标记（分布在MHC区域的18个微卫星和MHC区域外的18个常染色体微卫星）的遗传多样性。我们使用基于对比人口模型的两种方法，估计了每个位点F(st)与中性模型的偏差。这两种方法均显示MHC III类区域存在正选择信号，该信号比先前报道的标记DRACA的正选择信号更为显著，DRACA可能因其与III类区域接近而受到搭便车效应的影响。
