Tuyển tập các báo cáo nghiên cứu về sinh học được đăng trên tạp chí sinh học thế giới đề tài: The covariance between relatives conditional on genetic markers | Genet. Sel. Evol. 34 2002 657-678 657 INRA EDP Sciences 2002 DOI gse 2002030 Original article The covariance between relatives conditional on genetic markers Yuefu LIUa Gerald B. JANSENa Ching Y. LINa b a Department of Animal and Poultry Science University of Guelph Guelph ON N1G 2W1 Canada b Dairy and Swine Research and Development Centre Agriculture and Agri-Food Canada Received 13 August 2001 accepted 3 June 2002 Abstract - The development of molecular genotyping techniques makes it possible to analyze quantitative traits on the basis of individual loci. With marker information the classical theory of estimating the genetic covariance between relatives can be reformulated to improve the accuracy of estimation. In this study an algorithm was derived for computing the conditional covariance between relatives given genetic markers. Procedures for calculating the conditional relationship coefficients for additive dominance additive by additive additive by dominance dominance by additive and dominance by dominance effects were developed. The relationship coefficients were computed based on conditional QTL allelic transmission probabilities which were inferred from the marker allelic transmission probabilities. An example data set with pedigree and linked markers was used to demonstrate the methods developed. Although this study dealt with two QTLs coupled with linked markers the same principle can be readily extended to the situation of multiple QTL. The treatment of missing marker information and unknown linkage phase between markers for calculating the covariance between relatives was discussed. covariance between relatives molecular marker QTL transmission probability relationship matrix 1. INTRODUCTION Quantifying the resemblance between relatives is a fundamental issue in quantitative genetics. It is needed for estimating genetic parameters predicting breeding values planning mating schemes QTL mapping and marker assisted genetic evaluation. The study of
