Furthermore, behavior studies fail to show differences related to stress in an F10 advanced intercross and growth and fecundity remained unaltered. The selective sweep on chromosome 4 is specific for layer breeds only, suggesting that this region is Pterostilbene important for egg production. Indeed, earlier work indicates a connection between adrenergic control and fecundity and Rubin et al suggest that the sweep is associated with egg production traits. However, our measurements of egg production in terms of number of eggs laid and relative egg size in the F10 population did not support that hypothesis. Furthermore, an ongoing QTL analysis attempting to find regions demonstrating signatures of selection for fecundity has so far failed to find any QTL on chromosome 4. In addition, earlier work on adrenergic control of egg production failed to distinguish between adrenergic receptor subtypes and other subtypes may in fact be involved. Hence, Rubusoside ADRA2C does not seem to be associated with fecundity. Low fearfulness and high stress thresholds must have been essential traits for animals during early domestication. ADRA2C is the main modulator of epinephrine secretion from the adrenals and could therefore be a good target for domestication remodeling. Here we show that ADRA2C is expressed significantly more than ADRA2A in adrenals suggesting that ADRA2C, as in mice and rats, is the main controller of epinephrine release inhibition in the adrenals. However, no difference between RJF and WL on ADRA2C expression in the adrenals was found and stress related behavior in the F10 population showed no differences between genotype in TI and OF. These findings do not support the hypothesis that domestication has altered adrenal ADRA2C phenotype. A small but significant difference was observed as well as AD/AD in relaxed behavior after exposure to an aerial predator. The absolute values of this behavior are altogether very low in all groups, ranging of all expressed behaviors after exposure so the significant difference is probably of little biological relevance.