U.S. Department of Agriculture: Agricultural Research Service, Lincoln, Nebraska
Date of this Version
2008
Abstract
Why is animal ID needed?
Ways to physically label individual cattle
Disputes arise even when animal identification systems are in place
The dispute
The resolution
DNA is the label never removed from beef
A chromosome has genes and other DNA
Genes are encoded by sequences of DNA
What are SNPs?
Properties of SNPs
Ways to use DNA for traceback
Sometimes parentage testing is the last resort for DNA-based traceback
Using SNP markers for parentage
Accurate sire determination requires many DNA markers
Comparing the calf to the sire: elimination
Comparing the calf to a possible sire
The ideal parentage SNP markers
The ideal marker is frequent in all breeds
The ideal markers are evenly distributed across the genome
The ideal parentage marker scores accurately
Accurate scoring requires that SNPs
The nucleotide diversity in a typical region of the bovine genome
The consequence of 1 SNP every 80 bp
Bottom line: hidden SNPs may cause the wrong genotypes to be scored
DNA sequencing strategy: nested PCR
Parentage SNP population sequencing results
Physical map of one region with a parentage SNP
Immediate public access requested
Public access to detailed SNP information
Public internet access to flanking SNPs and allele frequencies by breed
Individual animal genotypes linked to tracefiles
Where are we now?
Comments
Published by Michael P. Heaton, PhD July 15, 2008 online at http://www.ars.usda.gov/sp2UserFiles/Place/54380570/HeatonPublications/HeatonParentage-Traceback2008o.pdf