Convergent evolution of conserved mitochondrial pathways underlies repeated adaptation to extreme environments
Convergent evolution of conserved mitochondrial pathways underlies repeated adaptation to extreme environments
复制标题
保守的线粒体途径的趋同进化是对极端环境的反复适应的基础
DOI：
10.1073/pnas.2004223117
复制
发表时间：
2020-07-14
影响因子：
11.1
通讯作者：
Shaw, Jennifer H.
中科院分区：
文献类型：
--
作者：
Greenway, Ryan;Barts, Nick;Shaw, Jennifer H.
极端环境考验生命的极限;然而，一些生物体在恶劣的条件下繁衍生息。嗜极端生物谱系激发了关于生物如何能够耐受生理化学应激源以及极端环境的重复殖民化是否由可预测和可重复的进化创新促进的问题。我们确定的机制基础的趋同进化的耐受性硫化氢（H2S）-一种有毒物质，损害线粒体功能-跨进化独立的谱系的鱼（Poecilia mexicana，Poeciliidae）从H2S丰富的春天。使用比较生化和生理分析，我们发现，线粒体功能维持在硫化氢的存在下，在硫化物弹簧P.墨西哥，但不是祖先血统的非硫化物栖息地由于收敛适应的主要毒性目标和主要解毒酶。全基因组的地方祖先分析表明，在不同的人群中增加的H2S耐受性的趋同进化可能是由常设的遗传变异和从头突变的选择相结合。在宏观进化尺度上，在10个独立的谱系的硫化物春鱼跨越多个属的Poeciliidae的H2S耐受性与收敛修饰和表达的变化与H2S毒性和解毒相关的基因。我们的研究结果表明，与线粒体基本过程相关的高度保守的生理途径的修饰介导了对理化胁迫的耐受性。此外，在跨越4000万年进化的谱系中，相同的途径、基因和（在某些情况下）密码子也参与了H2S适应。
Extreme environments test the limits of life; yet, some organisms thrive in harsh conditions. Extremophile lineages inspire questions about how organisms can tolerate physiochemical stressors and whether the repeated colonization of extreme environments is facilitated by predictable and repeatable evolutionary innova-tions. We identified the mechanistic basis underlying convergent evolution of tolerance to hydrogen sulfide (H2S)-a toxicant that impairs mitochondrial function-across evolutionarily indepen-dent lineages of a fish (Poecilia mexicana, Poeciliidae) from H2S-rich springs. Using comparative biochemical and physiological analyses, we found that mitochondrial function is maintained in the presence of H2S in sulfide spring P. mexicana but not ancestral lineages from nonsulfidic habitats due to convergent adaptations in the primary toxicity target and a major detoxification enzyme. Genome-wide local ancestry analyses indicated that convergent evolution of increased H2S tolerance in different populations is likely caused by a combination of selection on standing genetic variation and de novo mutations. On a macroevolutionary scale, H2S tolerance in 10 independent lineages of sulfide spring fishes across multiple genera of Poeciliidae is correlated with the conver-gent modification and expression changes in genes associated with H2S toxicity and detoxification. Our results demonstrate that the modification of highly conserved physiological path-ways associated with essential mitochondrial processes medi-ates tolerance to physiochemical stress. In addition, the same pathways, genes, and-in some instances-codons are impli-cated in H2S adaptation in lineages that span 40 million years of evolution.