Tuyển tập các báo cáo nghiên cứu về sinh học được đăng trên tạp chí sinh học thế giới đề tài: The effect of linkage on the additive 1 by additive covariance between relatives | 1 ỉ DEC Í99B Genet. Sei. Evol. 30 1998 409-421 409 Inra Elsevier Paris . . Original article Département de Génétlque Animate BIBLIOTHÈQUE i he effect oT Iinkage on the additive by additive covariance between relatives1 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 computation 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 parentoffspring covariance. All of the other relationships examined were affected by linkage. As recombination rate increased from to 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 parentoffspring. With inbreeding the parent-offspring covariance is also affected by linkage. Inra Elsevier Paris additive X additive relationship coefficient covariance between relatives identity by descent Resume - Effet du linkage sur les covariances entre apparentés pour les interactions de type additif X additif. En cas d epistasie le calcul de la covariance génétique entre apparentés nécessite le calcul du coefficient de parenté pour les termes d interaction additif X additif. Quand les loci sont lies le .
