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Genetic control of the environmental variance for birth weight in a divergent selection experiment in mice
Selection for robustness, less sensitivity with respect to environmental effects as indicated by a low variation around the optimum trait value, is already one of the main targets of selection. The aim of this study was to prove that environmental variance of birth weight may be modified by selection assigning the trait to the mothers. The experimental population analyzed here consists of six generations of a divergent selection experiment for environmental variance for birth weight. A model assuming heterogeneous environmental variance partially under genetic control was used. The phenotypic variances of the birth weight across generations showed differences between the high and low lines. There was a very important correlated response regarding litter size, having an advantage of 2.9 individuals at sixth generation for the low variability line. It seems to be possible to control genetically the environmental variance of birth weight.
Keywords:
robustness
selection
canalisation
birth weight
