BIO 321 Lecture Notes - Lecture 23: Quantitative Trait Locus, Phenotypic Plasticity, Selective Breeding
Document Summary
Review: heritability estimates can be calculated from artificial selection data. Determined by variation in several or many genes. Polygenic : how do we determine the architecture of variation in these traits. Where the genes are in the genome. Castle-wright estimator of the effective number of segregating loci underlying variation in a quantitative trait (castle 1921; wright 1968: assumes: Inbred or selected lines with large difference in mean trait value. High line has all positively acting alleles on the trait. Low line has all negatively acting alleles on the trait. All loci have the same magnitude of effect. Defining the genetic basis of adaptation: quantitative trait loci (qtls) Genetic-statistical construct, defined by an interval between two genetic markers and a magnitude of effect (% of variance accounted for: determined in a backcross or f2 populations from a cross between divergent strains or species. Molecular markers covering the entire genome are monitored.
