Variety of dogs' coats explained 狗毛发各不相同,原因很简单
文章来源:未知 文章作者:meng 发布时间:2009-08-28 06:17 字体: [ ]  进入论坛
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Wiry, smooth, curly or straight - the genetic2 reason for the the array of coats of different dog breeds is surprisingly simple, say scientists.

硬的、光滑的、弯曲的、直的--科学家称,不同品种的狗的毛皮也不一样的遗传因素出奇的简单。

Just three <a href=genes3 account for the different coats of domestic dogs" width="466" border="0" src="/upimg/090828/4_063725_1.jpg" />
Just three genes account for the different coats of domestic dogs

Just three genes account for the coat types that make canine4(犬的) pets so diverse. A team of researchers reports in the journal Science that different combinations of these genes account for all of the various textures6.

The research could aid the study of the causes of genetic diseases that affect both dogs and humans.

The team was led by Elaine Ostrander from the National Human Genome Research Institute (NHGRI) in Bethesda, US.

She and her colleagues took DNA7 samples from 1,000 dogs of more than 80 different breeds as well as from a number of wild dogs, including wolves.

These samples gave the scientists access to each dog's genome(基因组), which they were able to analyse(分析,观察). They looked for "signposts" of DNA variation, called single nucleotide(核苷) polymorphisms(多态性).

These signal a mutation8(变化,转变) or change in the DNA code that could account for a particular characteristic.

Edouard Cadieu, a member of Dr Ostrander's research team decided9 to use this genetic data to study the dogs' coats.

"There are lots of obvious differences between dog breeds," said Dr Ostrander, "but the coats are just remarkable10.

"It seems that every breed has a different coat. Some are long, some are short, some are curly, some are bristly(毛发丛生的), some are smooth, and there is every possible mixture therein(在其中,在那里)."

Dr Cadieu searched for patterns that might reveal the genetic cause of this variety.

Dr Ostrander explained: "For example, for long hair he looked for a commonality in long-haired breeds that's distinct from what we see in short-haired breeds.

"Edouard started out looking at texture5 - or wiry(坚硬的) hair - and quickly found that there was a single gene1 primarily responsible for that, as well as (for) the moustache and eyebrow11 pattern that you see in dogs like the schnauzer(德国种刚毛犬的一种)."

He then moved on to length, and then to curliness(卷缩,卷曲). And for each characteristic he identified a single gene that was primarily responsible.

Wild genes

In each case there was an ancestral or "wild-type" form of the gene that dogs inherited from wolves.

There was also a variant12 or "domesticated13 form" that had been selected by breeders looking for particular traits like longer hair.

Breeds with more wolf-like coats - such as those with short, straight hair like a beagle(比格犬) - displayed the wild-type version of the gene.

"Just by mixing and matching... these three different genes, we could account for most of the variation that we see in coats in domestic dogs," said Dr Ostrander.

The researchers say that the lessons learned from this study could help in the study of diseases that affect both humans and dogs.

Cathryn Mellersh, a geneticist from the Animal Health Trust in Suffolk, UK said: "This study is important because it proves a principle.

"You can use the dog genome as a model to investigate complex conditions and boil them down to a surprisingly small number of genes."

Dr Ostander concluded: "From a medical point of view, this simplicity14 is great news."

It means, she said, that the problems of diseases with a genetic basis are "much more solvable(可以解决的)".

Dr Ostander also expressed her thanks to all of the dog-owners who donated DNA samples from their pets.

"They've turned out to be extremely helpful, and this data set is just going to keep giving and giving."



点击收听单词发音收听单词发音  

1 gene WgKxx     
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。
2 genetic 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 genes 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
4 canine Lceyb     
adj.犬的,犬科的
参考例句:
  • The fox is a canine animal.狐狸是犬科动物。
  • Herbivorous animals have very small canine teeth,or none.食草动物的犬牙很小或者没有。
5 texture kpmwQ     
n.(织物)质地;(材料)构造;结构;肌理
参考例句:
  • We could feel the smooth texture of silk.我们能感觉出丝绸的光滑质地。
  • Her skin has a fine texture.她的皮肤细腻。
6 textures c5e62798e528da9080811018cbb27cd3     
n.手感( texture的名词复数 );质感;口感;(音乐或文学的)谐和统一感
参考例句:
  • I'm crazy about fabrics textures and colors and designs. 我喜欢各式各样的纺织物--对它的质地,色彩到花纹图案--简直是入了迷。 来自辞典例句
  • Let me clear up the point about the textures. 让我明确了一点有关的纹理。 来自互联网
7 DNA 4u3z1l     
(缩)deoxyribonucleic acid 脱氧核糖核酸
参考例句:
  • DNA is stored in the nucleus of a cell.脱氧核糖核酸储存于细胞的细胞核里。
  • Gene mutations are alterations in the DNA code.基因突变是指DNA密码的改变。
8 mutation t1PyM     
n.变化,变异,转变
参考例句:
  • People who have this mutation need less sleep than others.有这种突变的人需要的睡眠比其他人少。
  • So far the discussion has centered entirely around mutation in the strict sense.到目前为止,严格来讲,讨论完全集中于围绕突变问题上。
9 decided lvqzZd     
adj.决定了的,坚决的;明显的,明确的
参考例句:
  • This gave them a decided advantage over their opponents.这使他们比对手具有明显的优势。
  • There is a decided difference between British and Chinese way of greeting.英国人和中国人打招呼的方式有很明显的区别。
10 remarkable 8Vbx6     
adj.显著的,异常的,非凡的,值得注意的
参考例句:
  • She has made remarkable headway in her writing skills.她在写作技巧方面有了长足进步。
  • These cars are remarkable for the quietness of their engines.这些汽车因发动机没有噪音而不同凡响。
11 eyebrow vlOxk     
n.眉毛,眉
参考例句:
  • Her eyebrow is well penciled.她的眉毛画得很好。
  • With an eyebrow raised,he seemed divided between surprise and amusement.他一只眉毛扬了扬,似乎既感到吃惊,又觉有趣。
12 variant GfuzRt     
adj.不同的,变异的;n.变体,异体
参考例句:
  • We give professional suggestions according to variant tanning stages for each customer.我们针对每位顾客不同的日晒阶段,提供强度适合的晒黑建议。
  • In a variant of this approach,the tests are data- driven.这个方法的一个变种,是数据驱动的测试。
13 domesticated Lu2zBm     
adj.喜欢家庭生活的;(指动物)被驯养了的v.驯化( domesticate的过去式和过去分词 )
参考例句:
  • He is thoroughly domesticated and cooks a delicious chicken casserole. 他精于家务,烹制的砂锅炖小鸡非常可口。 来自《简明英汉词典》
  • The donkey is a domesticated form of the African wild ass. 驴是非洲野驴的一种已驯化的品种。 来自《简明英汉词典》
14 simplicity Vryyv     
n.简单,简易;朴素;直率,单纯
参考例句:
  • She dressed with elegant simplicity.她穿着朴素高雅。
  • The beauty of this plan is its simplicity.简明扼要是这个计划的一大特点。
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