title: From wild wolf to domestic dog: gene expression changes in the brain.
abstract: Despite the relatively recent divergence time between domestic dogs (Canis familiaris) and gray wolves (Canis lupus), the two species show remarkable behavioral differences. Since dogs and wolves are nearly identical at the level of DNA sequence, we hypothesize that the two species may differ in patterns of gene expression. We compare gene expression patterns in dogs, wolves and a close relative, the coyote (Canis latrans), in three parts of the brain: hypothalamus, amygdala and frontal cortex, with microarray technology. Additionally, we identify genes with region-specific expression patterns in all three species. Among the wild canids, the hypothalamus has a highly conserved expression profile. This contrasts with a marked divergence in domestic dogs. Real-time PCR experiments confirm the altered expression of two neuropeptides, CALCB and NPY. Our results suggest that strong selection on dogs for behavior during domestication may have resulted in modifications of mRNA expression patterns in a few hypothalamic genes with multiple functions. This study indicates that rapid changes in brain gene expression may not be exclusive to the development of human brains. Instead, they may provide a common mechanism for rapid adaptive changes during speciation, particularly in cases that present strong selective pressures on behavioral characters.
authors.affiliation: Department of Evolution, Genomics and Systematics, Uppsala University, Norbyvagen 18D, S-752 36 Uppsala, Sweden.
authors.forename: Peter
authors.initials: P
authors.lastname: Saetre
authors.forename: Julia
authors.initials: J
authors.lastname: Lindberg
authors.forename: Jennifer A
authors.initials: JA
authors.lastname: Leonard
authors.forename: Kerstin
authors.initials: K
authors.lastname: Olsson
authors.forename: Ulf
authors.initials: U
authors.lastname: Pettersson
authors.forename: Hans
authors.initials: H
authors.lastname: Ellegren
authors.forename: Tomas F
authors.initials: TF
authors.lastname: Bergström
authors.forename: Carles
authors.initials: C
authors.lastname: Vilà
authors.forename: Elena
authors.initials: E
authors.lastname: Jazin
mesh_terms: D000818:Animals; D000829:Animals, Domestic; D001921:Brain / Q000033:anatomy & histology / Q000502:physiology*; D002335:Carnivora / Q000235:genetics; D004285:Dogs / Q000235:genetics*; D005786:Gene Expression Regulation / Q000235:genetics*; D008969:Molecular Sequence Data; D020411:Oligonucleotide Array Sequence Analysis / Q000379:methods; D010802:Phylogeny; D012313:RNA / Q000378:metabolism; D012333:RNA, Messenger / Q000096:biosynthesis; D020133:Reverse Transcriptase Polymerase Chain Reaction / Q000379:methods; D013045:Species Specificity; D019596:Wolves / Q000235:genetics*
chemical_list: D012333:RNA, Messenger; D012313:RNA