Issue |
Genet. Sel. Evol.
Volume 34, Number 4, July-August 2002
|
|
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Page(s) | 465 - 479 | |
DOI | https://doi.org/10.1051/gse:2002018 |
Genet. Sel. Evol. 34 (2002) 465-479
DOI: 10.1051/gse:2002018
Test for positional candidate genes for body composition on pig chromosome 6
Cristina Óviloa, Angels Oliverb, José Luis Noguerac, Alex Clopd, Carmen Barragána, Luis Varonac, Carmen Rodrígueza, Miguel Toroa, Armand Sánchezd, Miguel Pérez-Encisoc and Luis Silióaa 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 F
2 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 85.4 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 included in the model.
Key words: candidate gene / H-FABP / LEPR / QTL / pigs
Correspondence and reprints: Cristina Óvilo
e-mail: ovilo@inia.es
© INRA, EDP Sciences 2002