title: Social odors conveying dominance and reproductive information induce rapid physiological and neuromolecular changes in a cichlid fish.
abstract: BACKGROUND
  Social plasticity is a pervasive feature of animal behavior. Animals adjust the expression of their social behavior to the daily changes in social life and to transitions between life-history stages, and this ability has an impact in their Darwinian fitness. This behavioral plasticity may be achieved either by rewiring or by biochemically switching nodes of the neural network underlying social behavior in response to perceived social information. Independent of the proximate mechanisms, at the neuromolecular level social plasticity relies on the regulation of gene expression, such that different neurogenomic states emerge in response to different social stimuli and the switches between states are orchestrated by signaling pathways that interface the social environment and the genotype. Here, we test this hypothesis by characterizing the changes in the brain profile of gene expression in response to social odors in the Mozambique Tilapia, Oreochromis mossambicus. This species has a rich repertoire of social behaviors during which both visual and chemical information are conveyed to conspecifics. Specifically, dominant males increase their urination frequency during agonist encounters and during courtship to convey chemical information reflecting their dominance status.
  
  
  RESULTS
  We recorded electro-olfactograms to test the extent to which the olfactory epithelium can discriminate between olfactory information from dominant and subordinate males as well as from pre- and post-spawning females. We then performed a genome-scale gene expression analysis of the olfactory bulb and the olfactory cortex homolog in order to identify the neuromolecular systems involved in processing these social stimuli.
  
  
  CONCLUSIONS
  Our results show that different olfactory stimuli from conspecifics' have a major impact in the brain transcriptome, with different chemical social cues eliciting specific patterns of gene expression in the brain. These results confirm the role of rapid changes in gene expression in the brain as a genomic mechanism underlying behavioral plasticity and reinforce the idea of an extensive transcriptional plasticity of cichlid genomes, especially in response to rapid changes in their social environment.
authors.affiliation: Unidade de Investigação em Eco-Etologia, ISPA - Instituto Universitário, Rua Jardim do Tabaco 34, 1149-041, Lisbon, Portugal. jsimoes@ispa.pt.|Integrative Behavioural Biology Lab, Instituto Gulbenkian de Ciência, Oeiras, Portugal. jsimoes@ispa.pt.|Champalimaud Neuroscience Programme, Champalimaud Foundation, Lisbon, Portugal. jsimoes@ispa.pt.
authors.forename: José M
authors.initials: JM
authors.lastname: Simões
authors.affiliation: CCMAR-CIMAR Laboratório Associado, Universidade do Algarve, Campus de Gambelas, 8005-139, Faro, Portugal. ebarata@uevora.pt.|Departamento de Biologia, Universidade de Évora, Apartado 94, 7002-554, Évora, Portugal. ebarata@uevora.pt.
authors.forename: Eduardo N
authors.initials: EN
authors.lastname: Barata
authors.affiliation: Institute for Cellular and Molecular Biology, University of Texas at Austin, Austin, TX, USA. rayna.harris@gmail.com.|Department of Integrative Biology, University of Texas at Austin, Austin, TX, USA. rayna.harris@gmail.com.
authors.forename: Rayna M
authors.initials: RM
authors.lastname: Harris
authors.affiliation: Institute for Cellular and Molecular Biology, University of Texas at Austin, Austin, TX, USA. loconnell@utexas.edu.|Department of Integrative Biology, University of Texas at Austin, Austin, TX, USA. loconnell@utexas.edu.|Current address: FAS Center for Systems Biology, Harvard University, Cambridge, MA, USA. loconnell@utexas.edu.
authors.forename: Lauren A
authors.initials: LA
authors.lastname: O'Connell
authors.affiliation: Institute for Cellular and Molecular Biology, University of Texas at Austin, Austin, TX, USA. hans@utexas.edu.|Department of Integrative Biology, University of Texas at Austin, Austin, TX, USA. hans@utexas.edu.|Institute for Neuroscience, University of Texas at Austin, Austin, TX, USA. hans@utexas.edu.
authors.forename: Hans A
authors.initials: HA
authors.lastname: Hofmann
authors.affiliation: Unidade de Investigação em Eco-Etologia, ISPA - Instituto Universitário, Rua Jardim do Tabaco 34, 1149-041, Lisbon, Portugal. ruiol@ispa.pt.|Integrative Behavioural Biology Lab, Instituto Gulbenkian de Ciência, Oeiras, Portugal. ruiol@ispa.pt.|Champalimaud Neuroscience Programme, Champalimaud Foundation, Lisbon, Portugal. ruiol@ispa.pt.
authors.forename: Rui F
authors.initials: RF
authors.lastname: Oliveira
mesh_terms: D000818:Animals; D001522:Behavior, Animal; D001921:Brain / Q000378:metabolism; D023681:Cichlids / Q000235:genetics* / Q000502:physiology; D005786:Gene Expression Regulation; D056084:Genetic Fitness / Q000235:genetics*; D009415:Nerve Net; D009812:Odorants; D012931:Social Environment