[导读] 爱丁堡大学的科学家们首次证实，代际遗传的特征不仅仅是由DNA决定的，细胞中的组蛋白的变化能够控制基因表达。
中国科技网4月3日报道（张微 编译）一项最新的研究显示，代际遗传的特征不仅仅是由DNA决定的，也可能是细胞中的其他物质引发的。
科学家们研究了在细胞中发现的一种叫组蛋白的物质，它们不是遗传密码的组成部分，但却扮演者DNA折叠时所依赖的线轴的角色。而且组蛋白与基因表达调控有关已经被证实。
研究人员发现，这些蛋白质自然发生的变化，会影响它们如何控制基因，能够一代代地持续下去，从而导致了遗传特征的延续。
研究首次证实DNA不是负责遗传特征的唯一因素。这项研究为遗传方式何时及如何发生，以及是否与特殊特征或健康情况相关联等相关研究的发展铺平了道路。
这也对环境条件引发的组蛋白的变化——如压力或饮食——是否能够影响基因功能的传递等研究提供了帮助。
这项研究也证实了科学家们长期以来的一个预期，通过组蛋白的变化，基因能够跨代控制。但是，研究人员说，这个过程是否常见还有待观察。
科学家在与人体细胞基因控制机理相似的酵母中做了实验，来验证这项理论。他们促使一个组蛋白发生变化，模仿那些导致其基因关闭的自然发生的变化。这种效果通过酵母细胞的后代遗传。
这项研究成果发表在《科学》杂志上，得到了由威康信托基金和EC epigenesys网络的支持。
这项研究的领导者，爱丁堡大学生物科学学院的Robin Allshire教授说：“我们的研究已经毫无疑问地证实，构成染色体的组蛋白轴的变化可以被复制并跨代遗传。我们的发现解决了一个重要课题，遗传特征是后生过程，意味着它们不完全取决于DNA的变化。”
DNA can't explain all inherited biological traits,
research shows
Characteristics passed between generations are not decided solely by DNA, but can be brought about by other material in cells, new research shows.
Scientists studied proteins found in cells, known as histones, which are not part of the genetic code, but act as spools around which DNA is wound. Histones are known to control whether or not genes are switched on.
Researchers found that naturally occurring changes to these proteins, which affect how they control genes, can be sustained from one generation to the next and so influence which traits are passed on.
The finding demonstrates for the first time that DNA is not solely responsible for how characteristics are inherited. It paves the way for research into how and when this method of inheritance occurs in nature, and if it is linked to particular traits or health conditions.
It may also inform research into whether changes to the histone proteins that are caused by environmental conditions - such as stress or diet - can influence the function of genes passed on to offspring.
The research confirms a long-held expectation among scientists that genes could be controlled across generations by such changes. However, it remains to be seen how common the process is, researchers say.
Scientists tested the theory by carrying out experiments in a yeast with similar gene control mechanisms to human cells. They introduced changes to a histone protein, mimicking those that occur naturally, causing it to switch off nearby genes. The effect was inherited by subsequent generations of yeast cells.
The study, published in Science, was supported by the Wellcome Trust and the EC EpiGeneSys Network.
Professor Robin Allshire, of the UniversityofEdinburgh'sSchoolofBiological Sciences, who led the study, said: "We've shown without doubt that changes in the histone spools that make up chromosomes can be copied and passed through generations. Our finding settles the idea that inherited traits can be epigenetic, meaning that they are not solely down to changes in a gene's DNA."
