A statistical model for genotype determination at a major locus in a progeny test design

• Published in: Genetics selection evolution (Paris) 1988-01, Vol.20 (2), p.211-226
• Main Authors: Elsen, J.M. (Institut National de la Recherche Agronomique, Castanet-Tolosan (France). Centre de Toulouse, Station d'Amelioration Genetique des Animaux), Vu Tien Khang, J, Le Roy, P
• Format: Article
• Language: English
• Subjects: ANIMAL REPRODUCTEUR; ANIMAL REPRODUCTOR; Biological and medical sciences; BREEDING STOCK; Classical genetics, quantitative genetics, hybrids; DESCENDANCE; EPREUVE SUR LA DESCENDANCE; EVALUACION; EVALUATION; Fundamental and applied biological sciences. Psychology; GENE; GENES; GENETIC PARAMETERS; Genetics of eukaryotes. Biological and molecular evolution; GENOTIPOS; GENOTYPE; GENOTYPES; LOCI; LOCUS; Methods, theories and miscellaneous; MODELE; MODELOS; PARAMETRE GENETIQUE; PARAMETROS GENETICOS; PROGENIE; PROGENY; PROGENY TESTING; PRUEBAS DE DESCENDENCIA
• ISSN: 0754-0264; 1297-9686; 0999-193X; 1297-9686
• DOI: 10.1186/1297-9686-20-2-211

Considering a normally distributed quantitative trait whose genetic variation is controlled by both an autosomal major locus and a polygenic component, and whose expression is influenced by environmental factors, a mixed model was developed to classify sires and daughters for their genotypes at the major locus in a progeny test design. Repeatability and genetic parameters reflecting the polygenic variation were assumed to be known. Posterior distribution of the sire genotypes and that of the daughters given the sire genotypes were derived. A method was proposed to estimate these posterior probabilities as well as the unknown parameters, and a method using the likelihood ratios to test specific genetic hypotheses was suggested. An iterative two-step procedure similar to the EM (expectation-maximization) algorithm was used to estimate the posterior probabilities and the unknown parameters. The operational value of this approach was tested with simulated data.