Evolution of a length polymorphism in the human PER3 gene, a component of the circadian system
Evolution of a length polymorphism in the human PER3 gene, a component of the circadian system
复制标题
DOI：
10.1177/0748730405281332
复制
发表时间：
2005-12-01
影响因子：
3.5
通讯作者：
Thomas, MG
中科院分区：
文献类型：
--
作者：
Nadkarni, NA;Weale, ME;Thomas, MG
周期同源物3（PER 3）是哺乳动物昼夜节律系统的一个组成部分，但其确切的作用是未知的。在人PER 3中存在双等位基因可变数目串联重复（VNTR）多态性，其由编码推定磷酸化结构域的区域中的54-bp序列的4或5个重复组成。这种多态性以前曾被报道与昼夜偏好（“早晨”和“晚上”）和延迟睡眠综合征有关。我们已经调查了这种变异在不同种族的土著人群中的全球等位基因频率。所有人群的多态性，与较短的（4重复）等位基因的频率范围从0.19（巴布亚新几内亚）到0.89（蒙古）。为了研究等位基因频率是否受到自然选择的影响，作者1）测试了与纬度和年平均日照的相关性（入射太阳光能量），使用经典标记来校正历史种群分化;他们2）比较了欧洲裔美国人、非洲裔美国人和东亚人群之间的等位基因频率差异，如使用F-ST测量的，F-ST值的经验零分布基于SNP联盟先前分型的假定中性基因座的单核苷酸多态性（SNP）的全基因组数据集。原住民群体之间的等位基因频率的变化并没有显示出一种模式，这将表明选择压力PER 3日长变化或平均年日照，和欧洲裔美国人，非洲裔美国人和东亚人之间的等位基因频率差异不是一个离群值相比，假定中性SNP的分布。因此，我们没有发现差异或平衡选择的证据，在当代模式的全球PER 3等位基因频率。
Period homologue 3 (PER3) is a component of the mammalian circadian system, although its precise role is unknown. A biallelic variable number tandem repeat (VNTR) polymorphism exists in human PER3, consisting of 4 or 5 repeats of a 54-bp sequence in a region encoding a putative phosphorylation domain. This polymorphism has previously been reported to associate with diurnal preference ("morningness" and "eveningness") and delayed sleep-phase syndrome. We have investigated the global allele frequencies of this variant in ethnically distinct indigenous populations. All populations were polymorphic, with the shorter (4-repeat) allele ranging in frequency from 0.19 (Papua New Guinea) to 0.89 (Mongolia). To investigate if allele frequency has been influenced by natural selection, the authors 1) tested for a correlation with latitude and mean annual insolation (incident sunlight energy), using classical markers to correct for historical population differentiation; and they 2) compared allele-frequency difference between European American, African American, and East Asian populations, as measured using F-ST, to an empirical null distribution of F-ST values based on a genome-wide dataset of single nucleotide polymorphisms (SNPs) of presumed neutral loci that were previously typed by The SNP Consortium. The variation in allele frequencies between indigenous populations did not show a pattern that would indicate selective pressure on PER3 resulting from day-length variation or mean annual insolation, and the allele-frequency difference between European Americans, African Americans, and East Asians was not an outlier when compared to the distribution for presumed neutral SNPs. We therefore find no evidence for differential or balancing selection in the contemporary pattern of global PER3 allele frequencies.