www射-国产免费一级-欧美福利-亚洲成人福利-成人一区在线观看-亚州成人

  Home>News Center>Life
         
 

Genetic map of dog may help humans
By Karen Kaplan (Times)
Updated: 2005-12-09 10:33

Scientists have decoded the complete genome of the domestic dog, a milestone announced Wednesday that provides a biological roadmap for unraveling human diseases and probing the mysterious bond between man and his best friend.

Dozens of researchers worked for two years deciphering and analyzing the 19,300 genes belonging to a 12-year-old boxer named Tasha. What they found was an exceptional correlation between the DNA of Canis familiaris and Homo sapiens, according to a study published today in the journal Nature.

"Humans and dogs have essentially the same genes," said lead author Kerstin Lindblad-Toh, co-director of the genome sequencing and analysis program at the Broad Institute of MIT and Harvard University. "Every gene has a gene with the same function in the other genome."

That closeness is reflected in the numerous diseases shared by dogs and humans, including cancer, heart disease, blindness, epilepsy and diabetes.

Of the 10 most common diseases in dogs, eight are important to humans.

The completion of the dog genome offers the possibility that idiosyncratic dog breeds 錕斤拷 often specifically bred for behavioral traits such as obedience, viciousness or docility 錕斤拷 will help illuminate the elusive genetic instructions that account for the infinite variety of human personalities.

"There are angry breeds, mean breeds, calm breeds and nice breeds," said Hans Ellegren, a professor of evolutionary biology at Uppsala University in Sweden. "This is now the best possibility we have to map the genes that are involved in these traits."


The purebred boxer was chosen from among 120 screened dogs because her genes showed the least amount of variation.

Tasha, a stout purebred female with a brown-and-white coat and drooping jowls, was selected from 120 dogs screened by the National Human Genome Research Institute in Bethesda, Md., because her genes showed the least amount of variation.

Only female dogs were considered because they have two X chromosomes, which researchers wanted to map in detail.

Scientists refused to say much about Tasha, the pet of an unidentified family.

Her stoical photo, however, now hangs prominently on the Mammalian Wall of Fame at the Broad Institute in Cambridge, Mass., where the sequencing work was completed.

The researchers reported that the complete dog genome consists of 2.4 billion chemical letters 錕斤拷 commonly known by the letters A, T, C and G 錕斤拷 compared with about 3 billion for humans.

In comparing Tasha's genome with genetic data from 10 other breeds, the researchers cataloged about 2.5 million specific genetic differences among dogs, which dictate differing sizes, proportions, temperaments and propensity for disease.

Dogs are a genetically unique case among mammals because of intensive selective breeding, which began a few hundred years ago and created the roughly 400 breeds that exist today.

The first breeds were probably molded for hunting and other work. By the Victorian era, about 150 years ago, form trumped function.

"Very rich Victorians wanted these strange dogs as curiosities, to set them apart from the common man," said Robert K. Wayne, an evolutionary biologist at UCLA who contributed to the study.

A breeder who noticed a puppy with short legs, for example, would cross it with its siblings to fix that trait in a line.

Before writing "On the Origin of Species," Charles Darwin visited dog breeders to observe the wide genetic variability among breeds that can result from selective breeding.

Before such breeding began in earnest, the chromosomes of dogs were as varied as in other animals.

By mating close relatives to produce animals with specific traits 錕斤拷 a kind of forced evolution 錕斤拷 breeders erased much of the genetic diversity within each breed.



"Bizarre pet" in a fever
Aniston sues paparazzo, warns media over topless photos
Miss World contestants in swimsuits
  Today's Top News     Top Life News
 

Appeals on death penalty in open court

 

   
 

China confirm fifth human case of bird flu

 

   
 

US, China eye cooperation on Iraq, Iran

 

   
 

FM: Japan military 'gossiping' hides issue

 

   
 

Washroom bustup may have caused shooting

 

   
 

Deals take Sino-Czech relations to a new high

 

   
  Genetic map of dog may help humans
   
  Eastern lore, Western allure
   
  Online sex chat is privacy
   
  Artist captures spirit of Forbidden City
   
  'Swan Lake' takes an acrobatic twist
   
  China ready for face transplant operations
   
 
  Go to Another Section  
 
 
  Story Tools  
   
  Feature  
  Could China's richest be the tax cheaters?  
Manufacturers, Exporters, Wholesalers - Global trade starts here.
Advertisement
         
主站蜘蛛池模板: 国产欧美va欧美va香蕉在线观 | www看片| 亚洲成人国产 | 国产综合成人亚洲区 | 九九热爱视频精品视频高清 | 综合亚洲精品一区二区三区 | 国产精品久久国产三级国不卡顿 | 亚洲欧美一区二区三区久本道 | 欧美xxxxx九色视频免费观看 | 日本三级成人午夜视频网 | 国产成人丝袜网站在线观看 | 亚洲国产日韩女人aaaaaa毛片在线 | 亚洲品质自拍视频网站 | 美女双腿打开让男人桶爽网站 | 国产最爽的乱淫视频国语对 | 大片毛片 | 日本特级淫片免费 | 国产精品自拍合集 | 一区二区三区国产精品 | 亚洲日本欧美产综合在线 | 亚洲 欧美 精品 | 亚洲自拍高清 | 波多野一区二区三区在线 | 美女扒开腿让男人桶个爽 | 成人欧美一区在线视频在线观看 | 亚洲二三区 | 亚洲国产午夜看片 | 九九全国免费视频 | 欧美一区二区在线免费观看 | 日韩一区二区三 | 成年免费观看 | 一级特黄特色的免费大片视频 | 香蕉久久综合精品首页 | 国产婷婷成人久久av免费高清 | 草久久免费视频 | 网站免费满18成年在线观看 | 欧美高清免费一级在线 | 亚洲自拍成人 | 日本精品视频在线播放 | 国产高清在线视频 | 手机看片免费基地你懂的 |