Methods to explain genomic estimates of breeding value

1
Methods to explain genomic estimates of breeding
value
2
Genomic Goals

• Predict young bulls and cows more accurately
• Compare actual DNA inherited
• Use exact relationship matrix G instead of
  expected values in A
• Trace chromosome segments
• Locate genes with large effects

3
How Related are Relatives?

• Example Full sibs
• are expected to share 50 of their DNA on average
  
• may actually share 45 or 55 of their DNA
  because each inherits a different mixture of
  chromosome segments from the two parents.
• Combine genotype and pedigree data to determine
  exact fractions

4
Genomic Relationships

• Measures of genetic similarity
• A Expected genes identical by descent from
  pedigree (Wright, 1922)
• G Actual of DNA shared (using genotype data)
• T genes shared that affect a given trait
  (using genotype and phenotype)
• Best measure depends on use

5
Markers vs QTLs

• Models contain markers, not QTLs
• M is markers inherited minus freq
• M M