'Obesity' is healthy for cetaceans? Evidence from pervasive positive selection in genes related to triacylglycerol metabolism.
'Obesity' is healthy for cetaceans? Evidence from pervasive positive selection in genes related to triacylglycerol metabolism.
复制标题
“肥胖”对鲸类动物有益吗？
DOI：
10.1038/srep14187
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发表时间：
2015-09-18
影响因子：
4.6
通讯作者：
Yang G
中科院分区：
文献类型：
--
作者：
Wang Z;Chen Z;Xu S;Ren W;Zhou K;Yang G
鲸目动物是一组二次适应的海洋哺乳动物，具有从陆地到完全水生的栖息地的过渡以及随后在世界各地的沃茨中的适应性辐射的神秘历史。许多生理和形态学特征的鲸目动物已经获得了响应这一激烈的栖息地转变;例如，增厚的鲸脂是最引人注目的变化之一，增加了他们的浮力，支持运动，并提供隔热。然而，鲸目动物脂肪增厚的遗传基础仍然很少探索。在这里，88个候选基因与三酰甘油代谢进行了研究，在代表性的鲸类动物和其他哺乳动物，以测试是否增厚的鲸脂相匹配的适应性进化的三酰甘油代谢相关基因。在88个候选基因中的41个中检测到阳性选择，并且这些基因的功能表征表明这些基因主要参与三酰甘油合成和脂解过程。此外，一些必需的调控基因在鲸类特有的谱系中经历了显著的正选择，而在对应的陆生哺乳动物中没有检测到选择信号。三酰甘油代谢相关基因中正选择的广泛发生表明它们在水生生物的次级适应中发挥着重要作用，并进一步表明“肥胖”可能是鲸类动物健康状况良好的指标。
Cetaceans are a group of secondarily adapted marine mammals with an enigmatic history of transition from terrestrial to fully aquatic habitat and subsequent adaptive radiation in waters around the world. Numerous physiological and morphological cetacean characteristics have been acquired in response to this drastic habitat transition; for example, the thickened blubber is one of the most striking changes that increases their buoyancy, supports locomotion, and provides thermal insulation. However, the genetic basis underlying the blubber thickening in cetaceans remains poorly explored. Here, 88 candidate genes associated with triacylglycerol metabolism were investigated in representative cetaceans and other mammals to test whether the thickened blubber matched adaptive evolution of triacylglycerol metabolism-related genes. Positive selection was detected in 41 of the 88 candidate genes, and functional characterization of these genes indicated that these are involved mainly in triacylglycerol synthesis and lipolysis processes. In addition, some essential regulatory genes underwent significant positive selection in cetacean-specific lineages, whereas no selection signal was detected in the counterpart terrestrial mammals. The extensive occurrence of positive selection in triacylglycerol metabolism-related genes is suggestive of their essential role in secondary adaptation to an aquatic life, and further implying that ‘obesity’ might be an indicator of good health for cetaceans.