title: Inside the heads of David and Goliath: environmental effects on brain morphology among wild and growth-enhanced coho salmon Oncorhynchus kisutch.
abstract: Transgenic and wild-type individual coho salmon Oncorhynchus kisutch were reared in hatchery and near-natural stream conditions and their brain and structure sizes were determined. Animals reared in the hatchery grew larger and developed larger brains, both absolutely and when controlling for body size. In both environments, transgenics developed relatively smaller brains than wild types. Further, the volume of the optic tectum of both genotypes was larger in the hatchery animals and the cerebellum of transgenics was smaller when reared in near-natural streams. Finally, wild types developed a markedly smaller telencephalon under hatchery conditions. It is concluded that, apart from the environment, genetic factors that modulate somatic growth rate also have a strong influence on brain size and structure.
authors.affiliation: Animal Ecology, Department of Ecology and Genetics, Evolutionary Biology Centre, Uppsala University, Norbyvägen 18D, 75236 Uppsala, Sweden. alexander.kotrschal@ebc.uu.se
authors.forename: A
authors.initials: A
authors.lastname: Kotrschal
authors.forename: L F
authors.initials: LF
authors.lastname: Sundström
authors.forename: D
authors.initials: D
authors.lastname: Brelin
authors.forename: R H
authors.initials: RH
authors.lastname: Devlin
authors.forename: N
authors.initials: N
authors.lastname: Kolm
mesh_terms: D000818:Animals; D030801:Animals, Genetically Modified; D001921:Brain / Q000033:anatomy & histology* / Q000254:growth & development; D002531:Cerebellum / Q000033:anatomy & histology / Q000254:growth & development; D004777:Environment; D017684:Oncorhynchus kisutch / Q000033:anatomy & histology* / Q000235:genetics* / Q000254:growth & development; D045483:Rivers; D013477:Superior Colliculi / Q000033:anatomy & histology / Q000254:growth & development