Institució Catalana de Recerca i Estudis Avançats, Centre for Genomic Regulation (CRG) and Universitat Pompeu Fabra, 88 Dr Aiguader, Barcelona 08003, Spain.
Proc Biol Sci. 2012 Dec 22;279(1749):5048-57. doi: 10.1098/rspb.2012.1108. Epub 2012 Sep 12.
A subject of extensive study in evolutionary theory has been the issue of how neutral, redundant copies can be maintained in the genome for long periods of time. Concurrently, examples of adaptive gene duplications to various environmental conditions in different species have been described. At this point, it is too early to tell whether or not a substantial fraction of gene copies have initially achieved fixation by positive selection for increased dosage. Nevertheless, enough examples have accumulated in the literature that such a possibility should be considered. Here, I review the recent examples of adaptive gene duplications and make an attempt to draw generalizations on what types of genes may be particularly prone to be selected for under certain environmental conditions. The identification of copy-number variation in ecological field studies of species adapting to stressful or novel environmental conditions may improve our understanding of gene duplications as a mechanism of adaptation and its relevance to the long-term persistence of gene duplications.
在进化理论中，一个广泛研究的课题是如何在基因组中长期维持中性、冗余的拷贝。同时，也描述了不同物种适应各种环境条件的适应性基因复制的例子。在这一点上，还为时过早，无法确定大量的基因拷贝是否最初通过增加剂量的正选择而达到固定。然而，文献中已经积累了足够多的例子，应该考虑这种可能性。在这里，我回顾了适应性基因复制的最新例子，并试图对哪些类型的基因在某些环境条件下可能更容易被选择进行概括。在适应压力或新环境条件的物种的生态实地研究中识别拷贝数变异，可能会提高我们对基因复制作为适应机制的理解，以及它与基因复制长期持续存在的相关性。
