Dissociation between several egg parameters in two quail strains genetically selected for resistance or sensitivity to acute hypoxia

1. 1. Eggs laid by females of two strains of Japanese quail, selected in a divergent way towards survival to an acute normobaric hypoxic challenge, were compared for their mass, the mass and the thickness of their eggshell and their water conductance (gh2o). 2. 2. Adults and embryos of the Ls+ strain survive at 70%, whereas those of the Ls-strain survive only at 20% to the acute hypoxia. 3. 3. While the birds of both sexes of each strain do not statistically differ either by their body masses or by various physiological and biochemical parameters, the eggs laid by the females of these strains differ significantly (0.001 < P < 0.01) in mass, eggshell thickness, egg shell mass and water vapor conductance (gh2o). 4. 4. Ls-quail lay lighter eggs with lighter and thinner eggshells and with higher gh2o than Ls+ quail. 5. 5. Crossing these two strains gives f1 hybrids (Ls±) whose females lay eggs that are statistically (0.001

laid by Ls+ in egg masses and shell masses, and statistically (0.001