the effect of linkage on the additive by additive covariance between relatives1连杆添加剂,添加剂的影响relatives1之间的协方差.pdfVIP

Original article The effect of linkage on the additive by additive covariance between 1 relatives Liviu R. Totir, Rohan L. Fernando Department of Animal Science, Iowa State University, Kildee Hall, Ames, IA 50011, USA (Received 22 September 1997; accepted 17 August 1998) Abstract - The additive x additive relationship coefficient needs to be calculated in order to compute genetic covariance between relatives. For linked loci, the compu- tation of this coefficient is not as simple as for unlinked loci. Recursive formulae are given to compute the additive x additive relationship coefficient for an arbitrary pedigree. Based on the recursive formulae, numerical values of the desired coefficient for selfed or outbred individuals are examined. The method presented provides the means to compute the additive x additive relationship coefficient for any situation assuming linkage. The effect of linkage on the covariance was examined for several pairs of relatives. In the absence of inbreeding, linkage has no effect on the parent- offspring covariance. All of the other relationships examined were affected by linkage. As recombination rate increased from 0.1 to 0.5, in descending order of percentage change in the covariance, the relationships ranked as follows: first cousins, double first cousins, grandparent-grandoffspring, half sibs, aunt-nephew, full sibs, parent- offspring. With inbreeding, the parent-offspring covariance is also affected by linkage. copy; Inra/Elsevier, Paris additive x additive relationship coefficient / covariance between relatives / identity by descent Résumé - Effet du linkage sur les covariances entre apparentés pour les in- teractions de t