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Anna-Carin Karlsson

PhD Student


MSc in biology, 2007, Linköping University.

PhD student in ethology och behaviour genetics, start 2007.

Research interests

During the last hundred years humans have bred chickens for high egg production and fast growth for meat production. Active selection for individuals that exhibit high egg production and fast growth results in a process of change named domestication. During domestication, not only traits of human interest change, but also other traits such as behaviour and appearance.    

Genes control both appearance and behaviour. One single gene can control several different traits, or interact with another gene which controls another trait. This is the explanation why one can select for high egg production and at the same time get a change in the color of the plumage.

I have studied two different genes that could have been of importance during the domestication of the chicken. PMEL17 is a gene that affects pigmentation of the plumage. Domesticated chickens often have a mutation in this gene that causes a white plumage, while the Red Jungle Fowl, the ancestor of fowl, has a dark plumage. We have seen that chickens with a mutation behave different in aggressive, explorative and social behavior in comparison to individuals without the mutation, in the same manner as the domesticated chicken differ from the Red Jungle fowl.

The other gene is called TSHR and we have so far seen that animals with a mutation in this gene hatch later, are less social dominant and less afraid of humans, which is similar to what we see in domesticated chickens.


Karlsson AC, Jensen P, Elgland M, Laur K, Fyrner T, Konradsson P, Laska M (2010): Red junglefowl have individual body odors. Journal of Experimental Biology 213, 1619–1624.

Karlsson AC, Kerje S, Andersson L, Jensen P (2010) Genotype at the PMEL17 locus affects social and explorative behaviour in chickens. Br Poult Sci 51: 170–177

Karlsson AC, Kerje S, Hallbook F, Jensen P (2009) The Dominant white mutation in the PMEL17 gene does not cause visual impairment in chickens. Vet Ophthalmol 12: 292–298

Karlsson, A.-C., Mormede, P., Kerje, S. & Jensen, P. (2011) Genotype on the pigmentation regulating PMEL17 gene affects behavior in chickens raised without physical contact with conspecifics. Behav Genet 41, 312–322.


E-mail: anna-carin.karlsson@liu.se

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Responsible for this page: Per Jensen
Last updated: 11/11/13