Tuyển tập các báo cáo nghiên cứu về sinh học được đăng trên tạp chí sinh học quốc tế đề tài: Impact of strong selection for the PrP major gene on genetic variability of four French sheep breeds (Open Access publication) | Genet. Sel. Evol. 40 2008 663-680 INRA EDP Sciences 2008 DOI gse 2008029 Available online at Original article Impact of strong selection for the PrP major gene on genetic variability of four French sheep breeds Open Access publication Isabelle Palhiere1 Mickael Brochard2 Katayoun Moazami-Goudarzi3 Denis Laloe4 Yves Amigues5 Bertrand Bed hom6 7 Etienne Neuts1 Cyril Leymarie1 Thais Pantano5 Edmond Paul Cribiu3 Bernard Bibe1 Etienne Verrier6 7 1INRA UR631 Station d Amelioration genetique des animaux 31326 Castanet-Tolosan France 2Institut de l Elevage Departement de Genetique 78352 Jouy-en-Josas France 3INRA UR339 Laboratoire de genetique biochimique et cytogenetique 78352 Jouy-en-Josas France 4INRA UR337 Station de genetique quantitative appliquee 78352 Jouy-en-Josas France 5LABOGENA 78352 Jouy-en-Josas France 6INRA UMR1236 Genetique et diversite animales 78352 Jouy-en-Josas France 7AgroParisTech UMR1236 Genetique et diversite animales 75231 Paris 05 France Received 7 February 2008 accepted 22 August 2008 Abstract - Effective selection on the PrP gene has been implemented since October 2001 in all French sheep breeds. After four years the ARR resistant allele frequency increased by about 35 in young males. The aim of this study was to evaluate the impact of this strong selection on genetic variability. It is focussed on four French sheep breeds and based on the comparison of two groups of 94 animals within each breed the first group of animals was born before the selection began and the second 3-4 years later. Genetic variability was assessed using genealogical and molecular data 29 microsatellite markers . The expected loss of genetic variability on the PrP gene was confirmed. Moreover among the five markers located in the PrP region only the three closest ones were affected. The evolution of the number of alleles heterozygote deficiency within population expected heterozygosity and the Reynolds distances agreed with the criteria from .