Genotype at the PMEL17 locus affects social and explorative behaviour in chickens.

1. We studied behaviour and brain gene expression in homozygous PMEL17 genotypes, using chickens originating from an advanced White Leghorn × red junglefowl intercross. The behavioural studies consisted of three social and one explorative behaviour test. There were significant differences between the genotypes in both social and explorative behaviour. 2. Gene expression studies showed no PMEL17 expression in brain, so the genotype differences must depend on extra-neural gene expression or expression during embryonic development. However, linkage or spurious family effects (genetic drift) can not be excluded. 3. The study strongly suggests a correlated effect between plumage colour and behaviour, and we conclude that PMEL17 may have a pleiotropic effect on social and explorative behaviour in chickens.