SSS 2012-05-04(在线收听

 Here’s a tale of genes, smells and pigs.

 
Most people have two copies of a gene that enables them to detect a steroidal pheromone called androstenone—which is found in male mammals, particularly porkers. But most pigs in developed countries have been chemically castrated. Which means much less androstenone in the meat. So, no strong smell.
 
Now Europe is considering a ban on castration. Might pork from these intact males smell bad to people with the right genes?
 
Researchers recruited 23 volunteers, who were screened for the ability to smell androstenone. Tests showed that those who were sensitive to the compound did indeed have two copies of the gene. And those who didn’t notice it or didn’t think it smelled bad mostly had one or no copies.
 
The researchers then challenged the subjects with pork to which androstenone was added to match levels that would be found in meat from uncastrated males. And the sensitive subjects thought the meat smelled and tasted much worse than did the insensitive tasters. The research was published in Public Library of Science One.
 
The scientists say ending pig castration could thus make some pork unpalatable to people with the common genes construct. Which might make consumers squeal.
 
Thanks for the minute for Scientific American 60 second Science, I am Cynthia Graber
 
squeal: to make a shrill cry or noise
 
steroidal: any of various compounds containing a 17-carbon 4-ring system and including the sterols and numerous hormones
  原文地址:http://www.tingroom.com/lesson/sasss/2012/5/180638.html