ABSTRACT
Functional mapping was originally conceived from a quantitative trait locus (QTL) mapping study of growth curves in an experimental cross. It has now been extensively extended to map any other dynamic or longitudinal traits, such as drug response (Wang and Wu, 2004; Gong et al., 2004). Also, the type of mapping population used can not be only derived from a controlled cross, but also random samples from a natural population. Functional mapping was further integrated with genetic association studies of single nucleotide polymorphisms (SNPs) to characterize haplotype variants that encode longitudinal responses (Lin et al., 2005). With such integration, functional mapping has been developed from QTL mapping to the identification of quantitative trait nucleotides (QTNs).
