線虫遺伝子が肥満治療の鍵？
(C) flickr & The Eggplant
線虫の遺伝子に，肥満治療に応用できそうな変異が発見された。線虫は，食べ物が少なくなるとダウアーと呼ばれる状態に変化する。これは線虫が厳しい環境に陥っても生き残るための術で，エネルギーをため込み，エネルギーを消費する細胞分裂や生殖などの活動は停止するというもの。ところが，今回発見された変異を持つ線虫は，脂肪を分解する酵素を阻害する物質がないため，ダウアーの状態でも細胞分裂を停止できず，蓄積したエネルギーを使い切って死んでしまう。人間でも同じ状況を作りだすことができれば脂肪がどんどん燃焼されるはずで，肥満治療への応用につながる可能性があるという。（吉田素子）
A previously unknown mutation(1) discovered in a common roundworm(2) holds the promise of(3) new treatments for obesity(4) in humans, McGill University researchers(5) say. Their study was published Dec. 3 in the journal Nature, and was funded by the Canadian Cancer(6) Society(7) and the Canadian Institutes of Health Research(8).
In lean times(9), a normal Caenorhabditis elegans(10) worm(11) goes into(12) a form of suspended animation(13) called "dauer(14)" that slows its metabolism(15) and allows(16) it to survive for extended periods without food.
"When they go into dauer, these worms radically(17) alter their metabolism," said Dr. Richard Roy, a cancer researcher at McGill's Department of Biology(18) specializing in(19) the control of cell division(20). "They shut down(21) everything energy-consuming(22), which includes foraging(23), cell division and reproduction(24)."
Unlike other "hibernating(25)" organisms(26), C. elegans maintains a degree of mobility(27) during dauer by stocking up on(28) energy in the form of(29) fats(30) - or lipids(31) - which they store in special cells(32) or reserves(33).
"This allows them to live up to six months without eating, instead of the two weeks they would otherwise have," Roy explained. A worm with the newly discovered mutation, however, will usually die within a week of going into dauer.
"These mutants somehow cannot shut down the process of cell division, which is why we noticed them in the first place," Roy said. "However, that's not what kills them. They cannot adjust their metabolism correctly. They store up(34) their six-month lipid reserves, but as soon as they shift into(35) dauer they use(36) them up within a few days.
(1) 変異 (2) 回虫 (3) ～の可能性を秘めている (4) 肥満 (5) 研究者 (6) 癌
(7) 学会（“Canadian Cancer Society”は学会名） (8) カナダ衛生研究所 (9) 食べ物の少ない時期
(10) 非寄生性線虫の学名 (11) 虫 (12) ～の状態となる (13) 活動停止状態 (14) ダウアー (15) 代謝
(16) （～A to B）AがBできるようにする (17) 根本的に (18) 生物学 (19) ～を専門とする (20) 細胞分裂
(21) 中断する (22) エネルギーを消費するような (23) 食糧探し (24) 生殖 (25) 冬眠する (26) 生物
(27) 運動性 (28) ～をため込むこと (29) ～の形で (30) 脂肪 (31) 脂質 (32) 細胞 (33) 予備の物
(34) ～を蓄積する (35) ～へと転換する (36) （～A up）Aを使い切る
