2015年经济学人 粒腺体影响男性寿命 粒腺体阻断

Mitochondria and male lifespan

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Women outlive men. An evolutionary¹ curiosity may explain this

Mankiller?

WHY past generations regarded women as the weaker sex is a mystery to anyone who has examined the question objectively,

for they are far stronger than men—outliving them in pretty well every society in the world.

Partly that is because men are more violent, and their violence is largely directed at other men.

But partly it is physiological³. Men seem to wear out faster than women do. Yet no one knows why.

Madeleine Beekman of the University of Sydney, Australia, and her colleagues, however, have a hypothesis.

As they outline in a paper in the Philosophical⁴ Transactions of the Royal Society,

they think at least some of the blame lies with subcellular structures called mitochondria (pictured),

which provide the body with its power by burning glucose⁶ and using the energy thus released to make ATP, a molecule⁷ that is biology's universal fuel.

Mitochondria are intriguing⁸. They are descendants of bacteria that teamed up with the ancestors of animal and plant cells about a billion years ago.

As such, they retain their own genes⁹. And this is where the problems start. To avoid fights between genetically¹⁰ different mitochondria in the same cell,

most species have arranged for their mitochondria to come from only one parent—usually the mother.

This means, as Dr Beekman notes, that a male's mitochondria are stuck in an evolutionary dead end.

They cannot evolve in male-specific ways, because no matter how much good they do a male body they inhabit, they will not be passed on to the next generation.

Male and female physiologies are sufficiently¹¹ similar for this not to be a central problem, but Dr Beekman thinks it may matter at the margins¹².

She observes that one disease, called Leber's hereditary¹³ optic neuropathy, which is caused by a faulty mitochondrial gene²,

occurs in only 10% of women whose cellular⁵ power-packs include the damaged gene, but in 50% of men whose mitochondria are so encumbered¹⁴.

The gene in question, in other words, is less likely to harm a woman than a man. She then lists a lot of other diseases,

including ones far commoner than Leber's hereditary optic neuropathy (such as cardiomyopathy, diabetes¹⁵ and several forms of deafness)

that sometimes or always have a mitochondrial component¹⁶, and speculates that some of these, too,

may prove to be either more common or more serious in men than in women. As far as her searches of the literature can show,

this is not something that has yet been looked into.

Part of the reason for this absence of information may be that few doctors think like evolutionary biologists,

so they fail to ask the appropriate questions. Dr Beekman's hypothesis may turn out to be wrong.

But it sounds eminently¹⁷ plausible¹⁸, and certainly worth investigating.

1 evolutionary   

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。

2 gene   

n.遗传因子，基因

参考例句：

• A single gene may have many effects.单一基因可能具有很多种效应。
• The targeting of gene therapy has been paid close attention.其中基因治疗的靶向性是值得密切关注的问题之一。

3 physiological   

adj.生理学的，生理学上的

参考例句：

• He bought a physiological book.他买了一本生理学方面的书。
• Every individual has a physiological requirement for each nutrient.每个人对每种营养成分都有一种生理上的需要。

4 philosophical   

adj.哲学家的，哲学上的，达观的

参考例句：

• The teacher couldn't answer the philosophical problem.老师不能解答这个哲学问题。
• She is very philosophical about her bad luck.她对自己的不幸看得很开。

5 cellular   

adj.移动的；细胞的，由细胞组成的

参考例句：

• She has a cellular telephone in her car.她的汽车里有一部无线通讯电话机。
• Many people use cellular materials as sensitive elements in hygrometers.很多人用蜂窝状的材料作为测量温度的传感元件。

6 glucose   

n.葡萄糖

参考例句：

• I gave him an extra dose of glucose to pep him up.我给他多注射了一剂葡萄糖以增强他的活力。
• The doctor injected glucose into his patient's veins.医生将葡萄糖注入病人的静脉。

7 molecule   

n.分子，克分子

参考例句：

• A molecule of water is made up of two atoms of hygrogen and one atom of oxygen.一个水分子是由P妈̬f婘̬ 妈̬成的。
• This gives us the structural formula of the molecule.这种方式给出了分子的结构式。

8 intriguing   

adj.有趣的；迷人的v.搞阴谋诡计(intrigue的现在分词)；激起…的好奇心

参考例句：

• These discoveries raise intriguing questions. 这些发现带来了非常有趣的问题。
• It all sounds very intriguing. 这些听起来都很有趣。 来自《简明英汉词典》

9 genes   

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

10 genetically   

adv.遗传上

参考例句：

• All the bees in the colony are genetically related. 同一群体的蜜蜂都有亲缘关系。
• Genetically modified foods have already arrived on American dinner tables. 经基因改造加工过的食物已端上了美国人的餐桌。 来自英汉非文学 - 生命科学 - 基因与食物

11 sufficiently   

adv.足够地，充分地

参考例句：

• It turned out he had not insured the house sufficiently.原来他没有给房屋投足保险。
• The new policy was sufficiently elastic to accommodate both views.新政策充分灵活地适用两种观点。

12 margins   

边( margin的名词复数 )； 利润； 页边空白； 差数

参考例句：

• They have always had to make do with relatively small profit margins. 他们不得不经常设法应付较少的利润额。
• To create more space between the navigation items, add left and right margins to the links. 在每个项目间留更多的空隙，加左或者右的margins来定义链接。

13 hereditary   

adj.遗传的，遗传性的，可继承的，世袭的

参考例句：

• The Queen of England is a hereditary ruler.英国女王是世袭的统治者。
• In men,hair loss is hereditary.男性脱发属于遗传。

14 encumbered   

v.妨碍，阻碍，拖累( encumber的过去式和过去分词 )

参考例句：

• The police operation was encumbered by crowds of reporters. 警方的行动被成群的记者所妨碍。
• The narrow quay was encumbered by hundreds of carts. 狭窄的码头被数百辆手推车堵得水泄不通。 来自辞典例句

15 diabetes   

n.糖尿病

参考例句：

• In case of diabetes, physicians advise against the use of sugar.对于糖尿病患者，医生告诫他们不要吃糖。
• Diabetes is caused by a fault in the insulin production of the body.糖尿病是由体內胰岛素分泌失调引起的。

16 component   

n.组成部分，成分，元件；adj.组成的，合成的

参考例句：

• Each component is carefully checked before assembly.每个零件在装配前都经过仔细检查。
• Blade and handle are the component parts of a knife.刀身和刀柄是一把刀的组成部分。

17 eminently   

adv.突出地；显著地；不寻常地

参考例句：

• She seems eminently suitable for the job. 她看来非常适合这个工作。
• It was an eminently respectable boarding school. 这是所非常好的寄宿学校。 来自《简明英汉词典》

18 plausible   

adj.似真实的，似乎有理的，似乎可信的

参考例句：

• His story sounded plausible.他说的那番话似乎是真实的。
• Her story sounded perfectly plausible.她的说辞听起来言之有理。