Tuyển tập các báo cáo nghiên cứu về sinh học được đăng trên tạp chí sinh học thế giới đề tài: Test for positional candidate genes for body composition on pig chromosome 6 | 465 Genet Sei. Evol. 34 2002 465-479 INRA EDP Sciences 2002 DOI gse 2002018 Original article Test for positional candidate genes for body composition on pig chromosome 6 Cristina Oviloa Angels Oliverb José Luis Noguerac Alex Clopd Carmen BarragÁna Luis Varonac Carmen Rodrigueza Miguel Toroa Armand Sánchezd Miguel Perez-Encisoc Luis Silióa a Departamento de Mejora Genética Animal SGIT-INIA 28040 Madrid Spain b Centre de Tecnologia de la Carn IRTA 17121 Monells Girona Spain c Area de Producció Animal Centre UdL-IRTA 25198 Lleida Spain d Departament de Ciència Animal i dels Aliments Universitat Autònoma de Barcelona 08193 Bellaterra Barcelona Spain Received 9 August 2001 accepted 14 February 2002 Abstract - One QTL affecting backfat thickness BF intramuscular fat content IMF and eye muscle area MA was previously localized on porcine chromosome 6 in an F2 cross between Iberian and Landrace pigs. This work was done to study the effect of two positional candidate genes on these traits H-FABP and LEPR genes. The QTL mapping analysis was repeated with a regression method using genotypes for seven microsatellites and two PCR-RFLPs in the H-FABP and LEPR genes. H-FABP and LEPR genes were located at and 107 cM respectively by linkage analysis. The effects of the candidate gene polymorphisms were analyzed in two ways. When an animal model was fitted both genes showed significant effects on fatness traits the H-FABP polymorphism showed significant effects on IMF and MA and the LEPR polymorphism on BF and IMF. But when the candidate gene effect was included in a QTL regression analysis these associations were not observed suggesting that they must not be the causal mutations responsible for the effects found. Differences in the results of both analyses showed the inadequacy of the animal model approach for the evaluation of positional candidate genes in populations with linkage disequilibrium when the probabilities of the parental origin of the QTL alleles are not .
