http://www.shaltzfarm.com/scrapie.html
<snip> "In the case of scrapie, one chromosone has been identified which helps to tell us how resistant to scrapie that animal may be. There are three main codons, or specific locations on that chromosone, that are tested for scrapie resistance. They are: Codon 136--controls resistance to scrapie type A Codon 154--controls onset of symptoms Codon 171--controls overall scrapie resistance Every codon has exactly two pieces of information present. But there can be more than two different bits of information that potentially could locate at that codon. These are called alleles. The alleles may both be the same at that codon, or they may be different from each other, but there are always two. One comes from the sire, one from the dam, of the animal. Each allele tells the sheep's body to do make a specific amino acid. For reasons not yet understood, these patterns of amino acids appear to prevent or allow infection with scrapie when the animal is exposed. Here's a chart to show what each allele is believed to do: chart ... " <snip> "US and European scrapie programs use slightly different systems of noting the genotypes of tested animals. The reason is that in North America there is only one strain of scrapie. In Europe, there is more than one type of scrapie, and codon 154 is important in identifying sheep resistant to those types. For the purpose of reference and comparison, these systems are listed here. ..." Diana in NC ( I told y'all I did alot of research before choosing BBS) ;-) =============================================== This message is from the Barbados Blackbelly Sheep mailing list. To respond to this message, send e-mail to [EMAIL PROTECTED] To unsubscribe or change your membership options, go to http://lists.coyotenet.net/mailman/listinfo/blackbelly
