title: Transmission of stress-induced learning impairment and associated brain gene expression from parents to offspring in chickens.
abstract: BACKGROUND
  Stress influences many aspects of animal behaviour and is a major factor driving populations to adapt to changing living conditions, such as during domestication. Stress can affect offspring through non-genetic mechanisms, but recent research indicates that inherited epigenetic modifications of the genome could possibly also be involved.
  
  
  RESULTS
  Red junglefowl (RJF, ancestors of modern chickens) and domesticated White Leghorn (WL) chickens were raised in a stressful environment (unpredictable light-dark rhythm) and control animals in similar pens, but on a 12/12 h light-dark rhythm. WL in both treatments had poorer spatial learning ability than RJF, and in both populations, stress caused a reduced ability to solve a spatial learning task. Offspring of stressed WL, but not RJF, raised without parental contact, had a reduced spatial learning ability compared to offspring of non-stressed animals in a similar test as that used for their parents. Offspring of stressed WL were also more competitive and grew faster than offspring of non-stressed parents. Using a whole-genome cDNA microarray, we found that in WL, the same changes in hypothalamic gene expression profile caused by stress in the parents were also found in the offspring. In offspring of stressed WL, at least 31 genes were up- or down-regulated in the hypothalamus and pituitary compared to offspring of non-stressed parents.
  
  
  CONCLUSIONS
  Our results suggest that, in WL the gene expression response to stress, as well as some behavioural stress responses, were transmitted across generations. The ability to transmit epigenetic information and behaviour modifications between generations may therefore have been favoured by domestication. The mechanisms involved remain to be investigated; epigenetic modifications could either have been inherited or acquired de novo in the specific egg environment. In both cases, this would offer a novel explanation to rapid evolutionary adaptation of a population.
authors.affiliation: IFM Biology, Linköping University, Linköping, Sweden.
authors.forename: Christina
authors.initials: C
authors.lastname: Lindqvist
authors.forename: Andrew M
authors.initials: AM
authors.lastname: Janczak
authors.forename: Daniel
authors.initials: D
authors.lastname: Nätt
authors.forename: Izabella
authors.initials: I
authors.lastname: Baranowska
authors.forename: Niclas
authors.initials: N
authors.lastname: Lindqvist
authors.forename: Anette
authors.initials: A
authors.lastname: Wichman
authors.forename: Joakim
authors.initials: J
authors.lastname: Lundeberg
authors.forename: Johan
authors.initials: J
authors.lastname: Lindberg
authors.forename: Peter A
authors.initials: PA
authors.lastname: Torjesen
authors.forename: Per
authors.initials: P
authors.lastname: Jensen
mesh_terms: D000818:Animals; D001522:Behavior, Animal; D001921:Brain / Q000378:metabolism*; D002645:Chickens / Q000502:physiology*; D003345:Corticosterone / Q000032:analysis; D044127:Epigenesis, Genetic; D005247:Feeding Behavior; D015870:Gene Expression; D007858:Learning; D020411:Oligonucleotide Array Sequence Analysis; D020133:Reverse Transcriptase Polymerase Chain Reaction; D013312:Stress, Physiological
chemical_list: D003345:Corticosterone