Tuyển tập các báo cáo nghiên cứu về sinh học được đăng trên tạp chí sinh học Journal of Biology đề tài: Estimating genetic parameters using an animal model with imaginary effects | Genet Sei Evol 1990 22 133-147 Elsevier INRA 133 Original article Estimating genetic parameters using an animal model with imaginary effects R Thompson1 K Meyer2 1 AFRO Institute of Animal Physiology and Genetics Edinburgh Research Station Roslin Midlothian EH25 9PS 2 Institute of Animal Genetics University of Edinburgh King s Buildings Edinburgh EH93JN UK Received 8 July 1988 accepted 24 November 1989 Summary - The estimation of additive genetic variance by maximum likelihood is discussed. The extension of reduced animal models when parents are not inbred to allow the use of existingalgorithms for maximum likelihood estimation of additive genetic variance is described. This involves the introduction of imaginary effects with negative variance and leads to computation using complex arithmetic Methods are developed to allow the computation to be carried out using only real arithmetic. This method has computational advantages when only a small proportion of animals have offspring. genetic parameter animal model estimation maximum likelihood Résumé Estimation de paramètres génétiques selon un modèle animal incluant des effets imaginaires On discute I estimation de la variance génétique additive par le maximum de vraisemblance. On décrit I extension des algorithmes disponibles d estimation par le maximum de vraisemblance de la variance généĩique additive à la situation d un modèle animal réduit au cas OÙ les parents ne sont pas consanguins. Ceci passe par I introduction d effets imaginaires de variance négative et conduit à des calculs en arithmétịque complexe. Des methodes sont développéẹs pour n utiliser que Ụarithmétique réelle. Cette méthode présente des avantages numériques quand une faible proportion seulement des animaux ont des descendants. paramètre génétỉque modèle animal estimation maximum de vraisemblance INTRODUCTION Additive genetic variance and heritability have most commonly been estimated in animal breeding data information from collateral relatives .
