饥饿使蠕虫寿命更长-凯发k8官网

饥饿使蠕虫寿命更长
文章来源:未知 文章作者:enread 发布时间:2014-06-20 08:03 字体: [ ] 
(单词翻译:双击或拖选)
worms "stop ageing" when they are starved of food and can go onto live twice as long as normal, a new study has shown.

一项新研究发现,蠕虫在缺乏食物的情况下会“停止老化”并能存活正常情况下两倍的时间。
 
researchers found that nematode(线虫) worms entered a state of arrested development(发育停滞) when food was taken away from them.
 
they continued to move and 1 but their cells and organs were suspended in an ageless, inactive state.
 
once the worms had access to food again, they began to grow normally and doubled their lifespan.
 
scientists from duke university, north carolina, us reported their findings in the journal plos genetics.
 
organisms including flies, 3, monkeys and worms have 4 been put on diets and shown to have their life spans extended by 30 to 200%, compared with those able to eat normally.
 
but how it happens 5 unclear.
 
the research team set out to determine how growing tissues respond to starvation.
 
tiny nematode worms - caenorhabditis elegans (c.elegans) - which are normally found underground, were chosen because they reach 6 in three to four days and develop in similar ways to each other.
 
they are also 7 and composed of only a few hundred cells, making changes in development easy to see under a microscope.
 
in the wild, the worms can experience 8(来回一次) of feast or famine(饥荒) that are likely to affect their development and lifespan.
 
the authors allowed the worms to grow to a specific developmental stage, just before the start of rapid cell growth.
 
food was then removed from the worms and their reactions observed.
 
within hours the worms' development stopped. once the worms could feed again, their development resumed and they grew into normal adults.
 
the authors found that worms' development was not continuous but stopped at two main stages, which they called checkpoints.
 
they explained that a worm needs enough 9 to pass through to the next developmental stages. if it is deprived of nutrients it has to wait until it has built them back up before its development can continue.
 
"organisms have to monitor their environment and decide whether or not it is 10(有责任的) to their development," lead author, adam schindler said. 
 
"if it isn't, they stop. if it is, they go. those checkpoints seem to exist to allow the animal to make that decision. and the decision has implications, because the resources either go to development or to survival."
 
the study found the worms could be starved for at least two weeks and still develop normally once they were fed. 
 
the period of arrested development allowed the worm to double its normal two-week lifespan.
 
mr schindler said: "from an 11 perspective this finding highlights the importance of an effective response to starvation for 12 fitness (survival and the passing on of 13 to the next generation) of the organism."
 
the team say their work may have implications for human ageing and also cancer biology, especially as the behaviour discovered in worms is similar to 14 lying 15(休眠的) for years before growing again.
 
they are now performing 2 studies to see if they can find another way to force worms to pause their development.
 
"the main question is how the decision is made to either arrest development or continue," mr schindler said. 
 
"understanding the key players in this decision could provide insights into why tissues 16 during ageing and reveal possible ways of slowing this degeneration."


点击收听单词发音收听单词发音  

1 qgyzp     
n.(牛马的)饲料,粮草;v.搜寻,翻寻
参考例句:
  • they were forced to forage for clothing and fuel.他们不得不去寻找衣服和燃料。
  • now the nutritive value of the forage is reduced.此时牧草的营养价值也下降了。
2 pgixp     
adj.遗传的,遗传学的
参考例句:
  • it's very difficult to treat genetic diseases.遗传性疾病治疗起来很困难。
  • each daughter cell can receive a full complement of the genetic information.每个子细胞可以收到遗传信息的一个完全补偿物。
3 7vizu     
n.酵母;酵母片;泡沫;v.发酵;起泡沫
参考例句:
  • yeast can be used in making beer and bread.酵母可用于酿啤酒和发面包。
  • the yeast began to work.酵母开始发酵。
4 bkzzzc     
adv.以前,先前(地)
参考例句:
  • the bicycle tyre blew out at a previously damaged point.自行车胎在以前损坏过的地方又爆开了。
  • let me digress for a moment and explain what had happened previously.让我岔开一会儿,解释原先发生了什么。
5 1kmzty     
n.剩余物,残留物;遗体,遗迹
参考例句:
  • he ate the remains of food hungrily.他狼吞虎咽地吃剩余的食物。
  • the remains of the meal were fed to the dog.残羹剩饭喂狗了。
6 vksyr     
n.成年,成人期
参考例句:
  • some infantile actions survive into adulthood.某些婴儿期的行为一直保持到成年期。
  • few people nowadays are able to maintain friendships into adulthood.如今很少有人能将友谊维持到成年。
7 yniwy     
adj.半透明的;透明的
参考例句:
  • the building is roofed entirely with translucent corrugated plastic.这座建筑完全用半透明瓦楞塑料封顶。
  • a small difference between them will render the composite translucent.微小的差别,也会使复合材料变成半透明。
8 2abe9936190c45115a3f6a38efb27c43     
n.拳击(或摔跤)比赛( bout的名词复数 );一段(工作);(尤指坏事的)一通;(疾病的)发作
参考例句:
  • for much of his life he suffered from recurrent bouts of depression. 他的大半辈子反复发作抑郁症。 来自《简明英汉词典》
  • it was one of fistiana's most famous championship bouts. 这是拳击界最有名的冠军赛之一。 来自《现代英汉综合大词典》
9 6a1e1ed248a3ac49744c39cc962fb607     
n.(食品或化学品)营养物,营养品( nutrient的名词复数 )
参考例句:
  • a lack of essential nutrients 基本营养的缺乏
  • nutrients are absorbed into the bloodstream. 营养素被吸收进血液。 来自《简明英汉词典》
10 pluy3     
adj.经得起检验的;顺从的;对负有义务的
参考例句:
  • his scientific discoveries are amenable to the laws of physics.他在科学上的发现经得起物理定律的检验。
  • he is amenable to counsel.他这人听劝。
11 ctqz7m     
adj.进化的;演化的,演变的;[生]进化论的
参考例句:
  • life has its own evolutionary process.生命有其自身的进化过程。
  • these are fascinating questions to be resolved by the evolutionary studies of plants.这些十分吸引人的问题将在研究植物进化过程中得以解决。
12 zmdzhm     
adj.最适宜的;最理想的;最令人满意的
参考例句:
  • what is the optimal mix of private and public property rights in natural resources?私人和国家的自然资源产权的最适宜的组合是什么?
  • optimal path planning is a key link for the sailing contest.帆船最优行驶路径规划是帆船比赛取胜的关键环节。
13 01914f8eac35d7e14afa065217edd8c0     
n.基因( gene的名词复数 )
参考例句:
  • you have good genes from your parents, so you should live a long time. 你从父母那儿获得优良的基因,所以能够活得很长。 来自《简明英汉词典》
  • differences will help to reveal the functions of the genes. 它们间的差异将会帮助我们揭开基因多种功能。 来自英汉非文学 - 生命科学 - 生物技术的世纪
14 6654305f758b5b5576a74cb007e8d079     
肿瘤( tumour的名词复数 )
参考例句:
  • blood vessels develop abnormally in cancer tumours. 在癌肿瘤中血管出现不正常。
  • this apparatus scans patients' brains for tumours. 这台仪器扫描检查病人的脑瘤。
15 d8uyk     
adj.暂停活动的;休眠的;潜伏的
参考例句:
  • many animals are in a dormant state during winter.在冬天许多动物都处于睡眠状态。
  • this dormant volcano suddenly fired up.这座休眠火山突然爆发了。
16 795ym     
v.退步,堕落;adj.退步的,堕落的;n.堕落者
参考例句:
  • he didn't let riches and luxury make him degenerate.他不因财富和奢华而自甘堕落。
  • will too much freedom make them degenerate?太多的自由会令他们堕落吗?
tag标签: food cell worms
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