The role of non-genetic inheritance in evolutionary rescue: epigenetic buffering, heritable bet hedging and epigenetic traps.
The role of non-genetic inheritance in evolutionary rescue: epigenetic buffering, heritable bet hedging and epigenetic traps.
复制标题
DOI：
10.1093/eep/dvv014
复制
发表时间：
2016-01
影响因子：
3.8
通讯作者：
Nakagawa S
中科院分区：
文献类型：
--
作者：
O'Dea RE;Noble DWA;Johnson SL;Hesselson D;Nakagawa S
据预测，快速的环境变化会危及种群的生存，而由此产生的强大的选择压力会侵蚀遗传变异，使进化拯救不太可能。非基因遗传可能为这个问题提供了一个解决方案，并有助于解释目前纯基因进化模型与经验数据之间缺乏契合。我们假设表观遗传修饰可以通过“表观遗传缓冲”促进进化拯救。通过促进由环境变化产生的新表型变异的遗传——一种我们称之为“遗传下注对冲”的策略——表观遗传修饰可以维持并增加种群的进化潜力。这一过程可能通过保存现有的遗传变异、释放隐性遗传变异和/或促进功能位点的突变来促进遗传适应。虽然我们证明了非基因遗传的例子在短期内往往是不适应的，但对表型变异和非适应可塑性的解释可能会在更长的时间尺度上揭示重要的进化含义。我们还讨论了适应性不良的表观遗传反应可能是由于“表观遗传陷阱”，即进化上的新因素（如内分泌干扰物）侵入现有的表观遗传机制。我们强调，需要更多的跨代表观遗传的生态相关工作。进行跨代环境影响研究的研究人员应该报告表型变异的测量结果，以便评估下注对冲和遗传下注对冲的可能性。未来的经验和理论工作需要评估遗传和表观遗传变异的相对重要性，以及它们的相互作用，对进化救援。
Rapid environmental change is predicted to compromise population survival, and the resulting strong selective pressure can erode genetic variation, making evolutionary rescue unlikely. Non-genetic inheritance may provide a solution to this problem and help explain the current lack of fit between purely genetic evolutionary models and empirical data. We hypothesize that epigenetic modifications can facilitate evolutionary rescue through ‘epigenetic buffering’. By facilitating the inheritance of novel phenotypic variants that are generated by environmental change—a strategy we call ‘heritable bet hedging’—epigenetic modifications could maintain and increase the evolutionary potential of a population. This process may facilitate genetic adaptation by preserving existing genetic variation, releasing cryptic genetic variation and/or facilitating mutations in functional loci. Although we show that examples of non-genetic inheritance are often maladaptive in the short term, accounting for phenotypic variance and non-adaptive plasticity may reveal important evolutionary implications over longer time scales. We also discuss the possibility that maladaptive epigenetic responses may be due to ‘epigenetic traps’, whereby evolutionarily novel factors (e.g. endocrine disruptors) hack into the existing epigenetic machinery. We stress that more ecologically relevant work on transgenerational epigenetic inheritance is required. Researchers conducting studies on transgenerational environmental effects should report measures of phenotypic variance, so that the possibility of both bet hedging and heritable bet hedging can be assessed. Future empirical and theoretical work is required to assess the relative importance of genetic and epigenetic variation, and their interaction, for evolutionary rescue.