title: Evaluation of "major genes" affecting disease resistance in poultry in respect to their potential for commercial breeding.
abstract: The evaluation of "major genes" is an essential step before their commercial utilization and transfer into a breeding population is considered. Of particular importance is, whether the effects of a "major gene" are independent of the genetic background into which it is introduced. This aspect has been investigated in respect to "major genes" affecting disease resistance in poultry. One of these controls genetic resistance to Leukosis virus (ALV) infection. Such infections have a negative effect on egg production and can result in increased mortality from causes other than Leukosis. The other "major gene" concerns B blood groups - genetic markers of the major histocompatibility complex (MHC) of the fowl - which influence resistance to Marek's disease. The effects of these major genes on egg production and/or viability were studied in three Leghorn lines of different origin and in crossbred combinations of these lines. For either of the "major genes", significant interactions with genetic characteristics of lines have been found which might induce changes of their effects on performance traits in different purebred and crossbred populations. To ignore this, could lead to false decisions when evaluating the potential benefit of known "major genes" for genetic improvement of economic merit. From the point of view of practical poultry breeding, "major genes" need to be evaluated on the basis of the effects achieved in crossbreds of the particular breeding lines, before making decisions about their utilization.
authors: Institut für Kleintierzucht der Bundesforschungsanstalt für Landwirtschaft, Bundesrepublik Deutschland.
authors: W
authors: W
authors: Hartmann
mesh_terms: D000818:Animals; D001353:Avian Leukosis / Q000235:genetics*; D001789:Blood Group Antigens / Q000235:genetics; D002645:Chickens / Q000097:blood / Q000235:genetics*; D005786:Gene Expression Regulation; D007113:Immunity, Innate; D008285:Major Histocompatibility Complex; D008380:Marek Disease / Q000235:genetics*
chemical_list: D001789:Blood Group Antigens