When all QTL mapping studies in a farm animal species are considered together and appropriate extrapolations are made, typical quantitative traits appear to be controlled by anywhere from five to a few dozen QTL. For the most part, effects of individual QTL are in the range of 1 to 3% of the trait mean. In some instances, the mapped QTL as a group are able to account for a large fraction of the observed genetic variation in the study population. Mapped QTL commonly exhibit various degrees of dominance, including overdominance; interactions (epi-stasis) among mapped QTL are common.
Was this article helpful?