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(单词翻译:双击或拖选)
From VOA Learning English, this is the Health & Lifestyle report.
It may seem like a moment in a science fiction movie. In a fierce battle, a creature loses an arm but, then, grows another one to take its place.
However, this is not science fiction. It is scientific fact. Some fish and amphibians1, such as salamanders, can regrow lost limbs and organs.
As mammals evolved they lost the ability to regrow, or regenerate2, parts of their body. However, experiments show that it may be possible to regain3 that ability.
Tropical freshwater zebrafish are popular pets. They are also popular as lab animals. Their embryos4 are clear, or translucent5. They can regrow damaged fins6, skin and hearts. Zebrafish are also genetically7 similar to humans.
In 2013, the website Sci-News reported that researchers had found that 70 per cent of “protein-coding human genes8” are related to genes found in the zebrafish. The report also said that researchers at the Wellcome Trust Sanger Institute in Britain also found that 84 per cent of genes known to be connected to human disease have a zebrafish counterpart.
These researchers published their findings in the scientific journal Nature. Sanger is a non-profit British genomics and genetics research institute.
So, it is no surprise that scientists at the University of Pittsburgh in Pennsylvania are using tiny zebrafish to regenerate severely9 damaged mouse hearts.
Scientist Wang Yadong is one of the Pittsburg researchers. He and his team are studying the ability of zebrafish to regenerate limbs and organs. Wang says you can cut away about 20 per cent of the zebrafish heart and it will regenerate. He add that same process may be able to help humans.
"So that amazing ability make(s) us think it's possible to borrow some of that repair regeneration mechanism10 and use that to help us to regenerate our heart."
Scientists injected an “extracellular matrix,” or ECM, from the heart of a zebrafish into a severely damaged mouse heart.
In biology, an extracellular matrix is a substance produced and released by cells that gives structural12 and biochemical support to surrounding cells. Think of ECM as cellular11 stuff that gives room and board to surrounding cells.
So, what did the researchers find?
They found that the heart muscle regenerated13 in days. They found something else. The healing was even faster when the ECM was taken from zebrafish that was itself in the process of re-growing damaged tissue.
Wang adds that if you had to choose between the two matrices, the “healing matrix” is more powerful of the two.
"Between the two, the healing matrix from the zebrafish heart is even more potent14 than the normal one."
A molecule15 called neuregulin 1 seems to play a major role in causing the regeneration to happen.
"We did see the zebrafish heart has more neuregulin 1 than the mouse heart. The healing zebrafish heart has even more than the normal. So, it does indicate that neuregulin probably plays a role but we have to do more study on that."
The next step will be to test the regenerative abilities of zebrafish ECM on larger mammals.
Words in This Story
limbs –n. referring to arms and or legs
regenerate –v. to regrow after being lost or damaged
translucent –adj. permitting light to pass through
counterpart –n. something that does the same job as something else
mechanism a process or system that is used to produce a particular result
extracellular matrix substance produced by cells and released into the environment in which the cells are embedded16; In biology, the extracellular matrix (ECM) is a collection of extracellular molecules17 released by cells that provides structural and biochemical support to the surrounding cells.
room and board –idiom a place to stay and food to eat
potent –adj. active, strong
matrix –n. something from which something else develops
indicate –v. to show
role –n. the part something plays in a system
1 amphibians | |
两栖动物( amphibian的名词复数 ); 水陆两用车; 水旱两生植物; 水陆两用飞行器 | |
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2 regenerate | |
vt.使恢复,使新生;vi.恢复,再生;adj.恢复的 | |
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3 regain | |
vt.重新获得,收复,恢复 | |
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4 embryos | |
n.晶胚;胚,胚胎( embryo的名词复数 ) | |
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5 translucent | |
adj.半透明的;透明的 | |
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6 fins | |
[医]散热片;鱼鳍;飞边;鸭掌 | |
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7 genetically | |
adv.遗传上 | |
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8 genes | |
n.基因( gene的名词复数 ) | |
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9 severely | |
adv.严格地;严厉地;非常恶劣地 | |
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10 mechanism | |
n.机械装置;机构,结构 | |
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11 cellular | |
adj.移动的;细胞的,由细胞组成的 | |
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12 structural | |
adj.构造的,组织的,建筑(用)的 | |
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13 regenerated | |
v.新生,再生( regenerate的过去式和过去分词 ) | |
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14 potent | |
adj.强有力的,有权势的;有效力的 | |
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15 molecule | |
n.分子,克分子 | |
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16 embedded | |
a.扎牢的 | |
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17 molecules | |
分子( molecule的名词复数 ) | |
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