Fay J C, Wittkopp P J
Department of Genetics, Washington University School of Medicine, St Louis, MO 63108, USA.
Heredity (Edinb). 2008 Feb;100(2):191-9. doi: 10.1038/sj.hdy.6801000. Epub 2007 May 23.
Surveys of gene expression reveal extensive variability both within and between a wide range of species. Compelling cases have been made for adaptive changes in gene regulation, but the proportion of expression divergence attributable to natural selection remains unclear. Distinguishing adaptive changes driven by positive selection from neutral divergence resulting from mutation and genetic drift is critical for understanding the evolution of gene expression. Here, we review the various methods that have been used to test for signs of selection in genomic expression data. We also discuss properties of regulatory systems relevant to neutral models of gene expression. Despite some potential caveats, published studies provide considerable evidence for adaptive changes in gene expression. Future challenges for studies of regulatory evolution will be to quantify the frequency of adaptive changes, identify the genetic basis of expression divergence and associate changes in gene expression with specific organismal phenotypes.
对基因表达的调查揭示了广泛物种内部和之间存在广泛的变异性。已有令人信服的案例表明基因调控存在适应性变化，但由自然选择导致的表达差异所占比例仍不清楚。区分由正选择驱动的适应性变化与由突变和遗传漂变导致的中性差异对于理解基因表达的进化至关重要。在这里，我们回顾了用于检测基因组表达数据中选择迹象的各种方法。我们还讨论了与基因表达中性模型相关的调控系统特性。尽管存在一些潜在的注意事项，但已发表的研究为基因表达的适应性变化提供了大量证据。调控进化研究未来面临的挑战将是量化适应性变化的频率，确定表达差异的遗传基础，并将基因表达变化与特定的生物体表型联系起来。
