Using a backcross to single animal for a QTL confirmation experiment
by
Ken G Dodds
AgResearch, Invermay
Coauthors: Allan M Crawford, Sin H Phua

Researchers usually follow up quantitative trait locus (QTL) mapping experiments with confirmation studies. One difficulty with these follow-up studies is to find another family where the QTL is segregating. If there has been additional information showing the association of the phenotype with a particular marker allele, this information might be useful for selecting a family to use. We have performed an experiment where a male individual homozygous for such a marker allele was chosen as a family founder. This male was used to generate daughters, and was then mated with these daughters to produce backcrossed grand-offspring. If the founder is homozygous for the QTL, and the QTL allele is rare in his first cross mates, then the QTL will be segregating in his offspring. We show how this design gives information when the founder is either homozygous or heterozygous for the QTL.

Date received: August 29, 2001