(c) Ulf Sirborn
Karolinska InstitutetのJuleen Zierath教授
運動により筋肉が変化して代謝が亢進することは知られているが，こうした健康によい変化が運動を始めて数分のうちに，DNAレベルで始まっていることが明らかになった。健康だが非活動的な男女に運動をさせて筋肉のDNAを調べたところ，遺伝コードは変わらないが，特定の位置のメチル基が減っていた。このメチル基の減少は，転写因子と呼ばれる物質の作用を通じ，筋肉が運動で変化するメカニズムを活性化するという。研究を行った専門家は，「運動の効果は1回ジョギングするだけで既に始まっている」と述べている。（吉田素子）
Exercise Changes the DNA
The genetic heredity a person is born with isn't that impossible to change as one might think. In a new study in Cell Metabolism, researchers of Karolinska Institutet show that when healthy but inactive men and women are made to exercise it actually alters their DNA -- in a matter of minutes.
The underlying genetic code stays the same. However, the DNA molecules within the muscle cells gets chemically and structurally altered in very particular ways, by gaining or losing marks of methyl groups on certain familiar DNA sequences. Those so called epigenetic modifications to the DNA, at precise locations, appear to be an important part of the physiological benefits of exercise.
"Our muscles are really plastic," says Juleen Zierath, Professor of Clinical Integrative Physiology at the Department of Molecular Medicine and Surgery. "We often say 'You are what you eat.' Well, muscle adapts to what you do. If you don't use it, you lose it and this is one of the mechanisms that allow that to happen."
The current study in Cell Metabolism shows that the DNA within skeletal muscle taken from people after a burst of exercise bears fewer methyl groups than it did before exercise. Those changes occur in stretches of DNA that serve as landing sites for different kinds of enzymes, called transcription factors, which in turn are involved in turning 'on' genes already known to be important in muscles' adaptation to exercise.
Juleen Zierath likens transcription factors to keys that unlock our genes.
［単語和訳］
genetic heredity：遺伝的形質 Cell Metabolism：細胞代謝（雑誌名） researchers：研究者 inactive：非活動的な in a matter of：ほんの～で
underlying：基本的な genetic code：遺伝コード molecules：分子 chemically：化学的に structurally：構造的に methyl groups：メチル基 DNA sequences：DNA配列 epigenetic modifications：後成的な遺伝子の修飾 physiological：生理学的
Clinical：臨床的な Integrative：総合的 Physiology：生理学 Molecular Medicine：分子医学 Surgery：外科学 You are what you eat：あなたの食べた物があなたになる（食べる物でその人の心身が決まるという意味のことわざ） adapts to：～に適応する
skeletal muscle：骨格筋 a burst of：一気に（急に）～すること serve as：～として働く landing sites：着地点 enzymes：酵素 transcription factors：転写因子 in turn：今度は turning on：スイッチを入れること genes：遺伝子 adaptation：適応
likens ～ to ---：～を---になぞらえる unlock：開錠する
