Rakyan Vardhman K, Beck Stephan
Wellcome Trust Sanger Institute, Hinxton, Cambridge, CB10 1SA, UK.
Curr Opin Genet Dev. 2006 Dec;16(6):573-7. doi: 10.1016/j.gde.2006.09.002. Epub 2006 Sep 26.
What determines phenotype is one of the most fundamental questions in biology. Historically, the search for answers had focused on genetic or environmental variants, but recent studies in epigenetics have revealed a third mechanism that can influence phenotypic outcomes, even in the absence of genetic or environmental heterogeneity. Even more surprisingly, some epigenetic variants, or epialleles, can be inherited by the offspring, indicating the existence of a mechanism for biological heredity that is not based on DNA sequence. Recent work from mouse models, human monozygotic twin studies, and large-scale epigenetic profiling suggests that epigenetically determined phenotypes and epigenetic inheritance are more common than previously appreciated.
决定表型的因素是生物学中最基本的问题之一。从历史上看，寻找答案的重点一直是基因或环境变异，但最近的表观遗传学研究揭示了第三种机制，即使在没有基因或环境异质性的情况下，这种机制也能影响表型结果。更令人惊讶的是，一些表观遗传变异，即表观等位基因，可以被后代遗传，这表明存在一种不基于DNA序列的生物遗传机制。来自小鼠模型、人类同卵双胞胎研究和大规模表观遗传图谱分析的最新研究表明，由表观遗传学决定的表型和表观遗传继承比以前认为的更为普遍。
