Genet. Sel. Evol.
Volume 40, Number 3, May-June 2008
|Page(s)||279 - 293|
|Published online||10 April 2008|
Genetic parameters related to environmental variability of weight traits in a selection experiment for weight gain in mice; signs of correlated canalised responseNoelia Ibáñez-Escriche1, Almudena Moreno2, Blanca Nieto3, Pepa Piqueras3, Concepción Salgado3 and Juan Pablo Gutiérrez3
1 Genètica i Millora Animal, IRTA, 25198 Lleida, Spain
2 Departamento de Mejora Genética Animal, INIA, 28040 Madrid, Spain
3 Departamento de Producción Animal, Universidad Complutense de Madrid, Av. Puerta de Hierro s/n, 28040 Madrid, Spain
(Received 19 March 2007; accepted 15 November 2007; published online 10 April 2008)
Abstract - Data from an experimental mice population selected from 18 generations to increase weight gain were used to estimate the genetic parameters associated with environmental variability. The analysis involved three traits: weight at 21 days, weight at 42 days and weight gain between 21 and 42 days. A dataset of 5273 records for males was studied. Data were analysed using Bayesian procedures by comparing the Deviance Information Criterion (DIC) value of two different models: one assuming homogeneous environmental variances and another assuming them as heterogeneous. The model assuming heterogeneity was better in all cases and also showed higher additive genetic variances and lower common environmental variances. The heterogeneity of residual variance was associated with systematic and additive genetic effects thus making reduction by selection possible. Genetic correlations between the additive genetic effects on mean and environmental variance of the traits analysed were always negative, ranging from -0.19 to -0.38. An increase in the heritability of the traits was found when considering the genetic determination of the environmental variability. A suggested correlated canalised response was found in terms of coefficient of variation but it could be insufficient to compensate for the scale effect associated with an increase of the mean.
Key words: canalisation / environmental variability / mice / weight gain
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© INRA, EDP Sciences 2008