COVARIANCE BETWEEN RELATIVES FOR A MARKED QUANTITATIVE TRAIT LOCUS

Best linear unbiased prediction (BLUP) can be applied to marker-assist ed selection. This application requires computation of the inverse of the conditional covariance matrix (G(upsilon)) of additive effects for the quantitative trait locus (QTL) linked to the marker locus (ML), g iven marker genotypes. This paper presents theory and algorithms to co nstruct G(upsilon) and to obtain its inverse efficiently. These algori thms are sufficiently general to accommodate situations (1) where pate rnal or maternal origin of marker alleles cannot be determined and (2) where the marker genotypes of some individuals in the pedigree are un known.