The hypothesis for this study is that a mutation in the TSHR gene will affect different traits which are considered central for domestication in chickens. In order to examine this, congenic (individuals differing at the same locus) hybrid chickens with alternative alleles on the TSHR gene (homozygote for both of the alternative alleles, wildtype and mutant and heterozygotes. ) will be bred and their phenotype will be compared against a background of randomly hybridized loci between Red Junglefowl and White Leghorn. Experiments will be conducted with different aspects of social, exploratory and fear related behaviours.    

The control group was represented of both White leghorn (WL), a domesticated breed and Red Junglefowl (Rjf), the wild ancestor . T he THSR individuals originated from an advanced intercross line between WL and Rjf, the parental birds were genotyped for their alleles on the TSHR locus and the heterozygotes were chosen for breeding. The TSHR individuals consisted of both homozygotes for both of the alternative allele s (Wildtyp and Mutant) and heterozygotes . All chickens were tested at the age of 10 – 14 weeks in four different tests; Aerial Predator, Fear of Human, Tonic Immobility and Social Hierarchy.