Is there adaptation in the human genome for taste perception and phase I biotransformation?
Is there adaptation in the human genome for taste perception and phase I biotransformation?
复制标题
DOI：
10.1186/s12862-019-1366-7
复制
发表时间：
2019-01-31
影响因子：
3.4
通讯作者：
Bertranpetit, Jaume
中科院分区：
文献类型：
--
作者：
Dobon, Begona;Rossell, Carla;Bertranpetit, Jaume
背景在现代人类扩张过程中，新的环境压力可能推动了适应，特别是与摄入物质的感知及其解毒相关的基因。因此，正向（适应性）选择可能发生在与味觉相关的基因中，以及与 CYP450 系统相关的基因中，因为它在潜在有毒化合物的生物转化中发挥着作用。使用 Hierarchical Boosting（不同选择测试的强大组合）对总共 91 个基因（味觉受体和 CYP450 超家族）进行了研究，以检测三个大陆人群最近正选择的特征：北欧人 (CEU)、东亚人 (CHB) 和非洲人 (YRI)。通过对千人基因组计划第三阶段的 26 个人群进行选择分析，对分析进行了完善。结果在三个大陆人群中，与味觉相关的基因尚未被积极选择。这一发现表明，与之前的研究结果相反，TAS2R38 和 TAS2R16 等基因中群体之间的不同等位基因频率并不是由于正向选择，而是由于遗传漂变。 CYP1 和 CYP2 基因之前也被认为处于正选择状态，但并未显示出选择性扫描的特征。然而，属于 CYP450 系统的三个基因已被 Hierarchical Boosting 识别为正选：CEU 中的 CYP3A4 和 CYP3A43，以及 CHB 中的 CYP27A1。 结论 在所研究的三个大陆人类群体中，已知味觉受体基因没有发现主要的适应性差异。然而，细胞色素 P450 系统中存在与现代人类走出非洲的扩张相关的重要遗传适应。我们确认了 CYP3A4 和 CYP3A43 在 CEU 中处于选择状态，并且我们首次报告 CYP27A1 在 CHB 中处于正选择状态。
BackgroundDuring the modern human expansion, new environmental pressures may have driven adaptation, especially in genes related to the perception of ingested substances and their detoxification. Consequently, positive (adaptive) selection may have occurred in genes related to taste, and in those related to the CYP450 system due to its role in biotransformation of potentially toxic compounds. A total of 91 genes (taste receptors and CYP450 superfamily) have been studied using Hierarchical Boosting, a powerful combination of different selection tests, to detect signatures of recent positive selection in three continental human populations: Northern Europeans (CEU), East Asians (CHB) and Africans (YRI). Analyses have been refined with selection analyses of the 26 populations of 1000 Genomes Project Phase 3.ResultsGenes related to taste perception have not been positively selected in the three continental human populations. This finding suggests that, contrary to results of previous studies, different allele frequencies among populations in genes such as TAS2R38 and TAS2R16 are not due to positive selection but to genetic drift. CYP1 and CYP2 genes, also previously considered to be under positive selection, did not show signatures of selective sweeps. However, three genes belonging to the CYP450 system have been identified by the Hierarchical Boosting as positively selected: CYP3A4 and CYP3A43 in CEU, and CYP27A1 in CHB.ConclusionsNo main adaptive differences are found in known taste receptor genes among the three continental human populations studied. However, there are important genetic adaptations in the cytochrome P450 system related to the Out of Africa expansion of modern humans. We confirmed that CYP3A4 and CYP3A43 are under selection in CEU, and we report for the first time CYP27A1 to be under positive selection in CHB.