National Center for Biotechnology Information, National Library of Medicine, National Institutes of Health, Bethesda, MD, USA.
Biol Direct. 2012 Aug 23;7:27. doi: 10.1186/1745-6150-7-27.
Prions are agents of analog, protein conformation-based inheritance that can confer beneficial phenotypes to cells, especially under stress. Combined with genetic variation, prion-mediated inheritance can be channeled into prion-independent genomic inheritance. Latest screening shows that prions are common, at least in fungi. Thus, there is non-negligible flow of information from proteins to the genome in modern cells, in a direct violation of the Central Dogma of molecular biology. The prion-mediated heredity that violates the Central Dogma appears to be a specific, most radical manifestation of the widespread assimilation of protein (epigenetic) variation into genetic variation. The epigenetic variation precedes and facilitates genetic adaptation through a general 'look-ahead effect' of phenotypic mutations. This direction of the information flow is likely to be one of the important routes of environment-genome interaction and could substantially contribute to the evolution of complex adaptive traits.
朊病毒是模拟的、基于蛋白质构象的遗传因子,能够赋予细胞有益的表型,尤其是在压力条件下。与遗传变异相结合,朊病毒介导的遗传可以被引导为与朊病毒无关的基因组遗传。最新的筛选表明,朊病毒很常见,至少在真菌中是这样。因此,在现代细胞中,从蛋白质到基因组的信息流是不可忽视的,这直接违反了分子生物学的中心法则。违反中心法则的朊病毒介导的遗传似乎是蛋白质(表观遗传)变异广泛纳入遗传变异的一种特定的、最激进的表现形式。这种表观遗传变异通过表型突变的一般“前瞻性效应”先于并促进了遗传适应。这种信息流的方向可能是环境-基因组相互作用的重要途径之一,可能对复杂适应性特征的进化做出重大贡献。