Data from: Genetic polymorphism in dopamine receptor D4 is associated with early body condition in a large population of greater flamingos, Phoenicopterus roseus

Body condition is an important determinant of fitness in many natural populations. However, as for many fitness traits, the underlying genes that regulate body condition remain elusive. The dopamine receptor D4 gene (DRD4) is a promising candidate as dopamine is known to play an important role in the regulation of food intake and the metabolism of both glucose and lipids in vertebrates. In this study we take advantage of a large dataset of greater flamingos, Phoenicopterus roseus, to test whether DRD4 polymorphism predicts early body condition (EBC) while controlling for whole genome effects of inbreeding and outbreeding using microsatellite multi-locus heterozygosity (MLH). We typed 670 of these individuals for exon 3 of the homologue of the human DRD4 gene and 10 microsatellite markers. When controlling for effects of yearly environmental variations and differences between sexes, we found strong evidence of an association between exon 3 DRD4 polymorphisms and EBC, with 2.2-2.3% of the variation being explained by DRD4 polymorphism, whereas there was only weak evidence that MLH predicts EBC. Because EBC is most likely a polygenic trait, this is a considerable amount of variation explained by a single gene. This is to our knowledge the first study to show an association between exon 3 DRD4 polymorphism and body condition in nonhuman animals. We anticipate that the DRD4 gene as well as other genes coding for neurotransmitters and their receptors may play an important role in explaining variation in traits that affect fitness.身体状况是诸多自然种群中影响个体适合度（fitness）的重要决定因素。然而，与诸多适合度相关性状一样，调控身体状况的内在基因仍未明确。多巴胺D4受体基因（dopamine receptor D4 gene, DRD4）是极具潜力的候选基因，因为已知多巴胺在脊椎动物的摄食调控、葡萄糖与脂质代谢过程中发挥关键作用。本研究利用大红鹳（Phoenicopterus roseus）的大型数据集，旨在通过微卫星多位点杂合度（microsatellite multi-locus heterozygosity, MLH）控制近交与远交的全基因组效应，检验DRD4多态性是否可预测早期身体状况（early body condition, EBC）。研究人员对670个个体的人类DRD4基因同源外显子3以及10个微卫星标记进行了基因分型。在控制年度环境差异与性别差异的影响后，本研究发现DRD4外显子3多态性与早期身体状况存在显著关联，DRD4多态性可解释2.2%~2.3%的性状变异；而微卫星多位点杂合度预测早期身体状况的证据仅较为微弱。鉴于早期身体状况极可能为多基因性状，单个基因即可解释如此程度的变异，这一结果颇具意义。据我们所知，本研究是首个在非人类动物中发现DRD4外显子3多态性与身体状况存在关联的研究。我们推测，DRD4基因以及其他编码神经递质及其受体的基因，或许在解释影响适合度的性状变异方面发挥着重要作用。