Adaptive evolution of the osmoregulation-related genes in cetaceans during secondary aquatic adaptation.
Adaptive evolution of the osmoregulation-related genes in cetaceans during secondary aquatic adaptation.
复制标题
鲸目动物二次水生适应过程中渗透调节相关基因的适应性进化
DOI：
10.1186/1471-2148-13-189
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发表时间：
2013-09-09
影响因子：
3.4
通讯作者：
Yang G
中科院分区：
文献类型：
--
作者：
Xu S;Yang Y;Zhou X;Xu J;Zhou K;Yang G
研究背景鲸类在从陆地环境向高渗环境进化的过程中，渗透调节是一个主要的挑战。已经提出了几种生理机制来维持鲸目动物的水盐平衡，但它们的遗传和进化基础仍然很少探索。目前的研究调查的基因参与在鲸类中的调节，并将它们与他们的同行在陆地哺乳动物，以测试是否发生适应性进化过程中二次aquatic adaptation.ResultsThe本研究分析了11个鲸类物种，代表所有的主要鲸类分支的11个调节相关基因的分子进化。结果表明正选择作用于血管紧张素转换酶（ACE）、血管紧张素原（AGT）、SLC 14 A2和水通道蛋白2（AQP 2）。AQP 2和SLC 14 A2的阳性选择的证据表明，这些基因的适应性进化有助于增强水和尿素运输的能力，从而导致尿液浓缩，这是维持水平衡的有效机制。相比之下，一系列积极选择的氨基酸残基中确定的ACE和AGT（两个关键成员的肾素-血管紧张素-醛固酮系统，RAAS）蛋白质的鲸目动物表明，RAAS可能已经适应，以维持水和盐的平衡，以应对高渗环境。激进的氨基酸变化，积极选择的网站分布在大多数内部和终端分支的鲸类动物生殖，这表明普遍的适应性进化的鲸类动物的起源和随后的diversified.ConclusionsThis适应性进化的调节相关基因的分子进化的鲸类动物在选择压力从一般高渗环境。四个基因，即，AQP 2，SLC 14 A2，ACE和AGT在鲸目动物中受到正向选择，这表明鲸目动物可能已经适应了维持其水盐平衡。这也表明，鲸目动物可能已经进化出一种有效而复杂的生物调节机制。
BackgroundOsmoregulation was a primary challenge for cetaceans during the evolutionary transition from a terrestrial to a mainly hyperosmotic environment. Several physiological mechanisms have been suggested to maintain the water and salt balance in cetaceans, but their genetic and evolutionary bases remain poorly explored. The current study investigated the genes involved in osmoregulation in cetaceans and compared them with their counterparts in terrestrial mammals to test whether adaptive evolution occurred during secondary aquatic adaptation.ResultsThe present study analyzed the molecular evolution of 11 osmoregulation-related genes in 11 cetacean species, which represented all of the major cetacean clades. The results demonstrated positive selection acting on angiotensin converting enzyme (ACE), angiotensinogen (AGT), SLC14A2, and aquaporin 2 (AQP2). This evidence for the positive selection of AQP2 and SLC14A2 suggests that the adaptive evolution of these genes has helped to enhance the capacity for water and urea transport, thereby leading to the concentration of urine, which is an efficient mechanism for maintaining the water balance. By contrast, a series of positively selected amino acid residues identified in the ACE and AGT (two key members of the renin-angiotensin-aldosterone system, RAAS) proteins of cetaceans suggests that RAAS might have been adapted to maintain the water and salt balance in response to a hyperosmotic environment. Radical amino acid changes in positively selected sites were distributed among most internal and terminal branches of the cetacean phylogeny, which suggests the pervasively adaptive evolution of osmoregulation since the origin of cetaceans and their subsequent diversification.ConclusionsThis is the first comprehensive analysis of the molecular evolution of osmoregulation-related genes in cetaceans in response to selection pressure from a generally hyperosmotic environment. Four genes, i.e., AQP2, SLC14A2, ACE, and AGT were subject to positive selection in cetaceans, which suggests that cetaceans may have adapted to maintain their water and salt balance. This also suggests that cetaceans may have evolved an effective and complex mechanism for osmoregulation.
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DOI：
10.1073/pnas.0712338105
发表时间：
2008-02-26
影响因子：
11.1
作者：
Fenton, Robert A.;Moeller, Hanne B.;Knepper, Mark A.
通讯作者：
Knepper, Mark A.
影响因子：
1.4
作者：
HEDGES, NA;GASKIN, DE;SMITH, GJD
通讯作者：
SMITH, GJD
影响因子：
3.9
作者：
HUGHES, AL;HUGHES, MK
通讯作者：
HUGHES, MK
影响因子：
64.8
作者：
FUSHIMI, K;UCHIDA, S;SASAKI, S
通讯作者：
SASAKI, S
影响因子：
2.1
作者：
Harrison-Bernard, Lisa M.
通讯作者：
Harrison-Bernard, Lisa M.