Animal genotyping method
This invention relates to a method for determining whether a bovine animal possesses a gene for β-casein A 2 or the gene for β-casein A 1 in its milk by testing the DNA of the bovine animal for the presence of at least one DNA marker (excluding those DNA markers present in the sequence of the genes themselves). In particular, the method uses SNPs as DNA markers for the β-casein A 2 and β-casein A 1 genes.
1. A method for determining whether a bovine animal possesses a gene encoding for the protein β-casein A 1 or a gene encoding for the protein β-casein A 2 by testing the DNA of the animal for the presence of at least one DNA marker for either of the β-casein A 1 or β-casein A 2 genes, where the at least one DNA marker is located in a gene encoding for the protein α s2 -casein.
2. The method as claimed in claim 1 , where the at least one DNA marker is located in exon 17 or exon 18 of the α s2 -casein gene.
3. The method as claimed in claim 1 , where each of the at least one DNA marker is an SNP.
4. The method as claimed in claim 3 , where the SNP is SEQ ID No:21.
5. The method as claimed in claim 4 which further comprises testing for the presence of the SNPs of SEQ ID No:19 and SEQ ID No:23.
6. The method as claimed in claim 5 where the bovine animal is a cow.
7. The method as claimed in claim 6 , where the presence of the at least one DNA marker is linked with the presence or absence of β-casein A 1 in milk produced by the cow.
8. The method as claimed in claim 6 , where the presence of the at least one DNA marker is linked with the presence or absence of β-casein A 2 in milk produced by the cow.
9. The method as claimed in claim 1 , where the at least one DNA marker is a marker for the gene encoding for β-casein A 1 .
10. The method as claimed in claim 1 , where the at least one DNA marker is a marker for the gene encoding for β-casein A 2 .
11. The method as claimed in claim 1 , where the DNA of the bovine animal is obtained from any tissue of the bovine animal which contains or contained nucleated cells.
12. The method as claimed in claim 11 , where the DNA of the animal is obtained from blood, sperm, hair, or milk of the animal.
13. A method of producing milk substantially free of β-casein A 1 including the steps:
determining whether one or more bovine cows possesses a gene encoding for the protein β-casein A 1 or a gene encoding for the protein β-casein A 2 according to the method of claim 1 ;
selecting those cows that do not have a gene encoding for the protein β-casein A 1 ; and
milking the selected cows.
14. The method as claimed in claim 13 , where the milk contains β-casein which is substantially all β-casein A 2 .
15. A method of forming a herd of bovine cows by testing the DNA of each cow in accordance with the method of claim 1 and selecting those cows that possess a gene encoding for β-casein A 2 and do not possess a gene encoding for β-casein A 1 .