DOI: 10.1051/gse:2001118

Genet. Sel. Evol. 33 (2001) 231-247

Power analysis of QTL detection in half-sib families using selective DNA pooling

Jesús Á. Baro^a, Carlos Carleos^a, Norberto Corral^a, Teresa López^a and Javier Cañón<sup>b

a</sup>  Departamento de Estadística, Universidad de Oviedo, Facultad de Ciencias, C/Calvo Sotelo, 33007 Oviedo, Asturias, Spain
^b  Departamento de Producción Animal, Universidad Complutense, 28040 Madrid, Spain

(Received 21 February 2000; accepted 29 September 2000)

Abstract
Individual loci of economic importance (QTL) can be detected by comparing the inheritance of a trait and the inheritance of loci with alleles readily identifiable by laboratory methods (genetic markers). Data on allele segregation at the individual level are costly and alternatives have been proposed that make use of allele frequencies among progeny, rather than individual genotypes. Among the factors that may affect the power of the set up, the most important are those intrinsic to the QTL: the additive effect of the QTL, and its dominance, and distance between markers and QTL. Other factors are relative to the choice of animals and markers, such as the frequency of the QTL and marker alleles among dams and sires. Data collection may affect the detection power through the size of half-sib families, selection rate within families, and the technical error incurred when estimating genetic frequencies. We present results for a sensitivity analysis for QTL detection using pools of DNA from selected half-sibs. Simulations showed that conclusive detection may be achieved with families of at least 500 half-sibs if sires are chosen on the criteria that most of their marker alleles are either both missing, or one is fixed, among dams.

Key words: quantitative trait loci / genetic marker / selective DNA pooling

Correspondence and reprints: Jesús Á. Baro
    e-mail: baro@arrakis.es

© INRA, EDP Sciences 2001