Large Sex Differences in Chicken Behavior and Brain Gene Expression Coincide with Few Differences in Promoter DNA-Methylation
2014 (English)In: PLoS ONE, ISSN 1932-6203, Vol. 9, no 4, e96376- p.Article in journal (Refereed) Published
While behavioral sex differences have repeatedly been reported across taxa, the underlying epigenetic mechanisms in thebrain are mostly lacking. Birds have previously shown to have only limited dosage compensation, leading to high sex bias ofZ-chromosome gene expression. In chickens, a male hyper-methylated region (MHM) on the Z-chromosome has beenassociated with a local type of dosage compensation, but a more detailed characterization of the avian methylome islimiting our interpretations. Here we report an analysis of genome wide sex differences in promoter DNA-methylation andgene expression in the brain of three weeks old chickens, and associated sex differences in behavior of Red Junglefowl(ancestor of domestic chickens). Combining DNA-methylation tiling arrays with gene expression microarrays we show that aspecific locus of the MHM region, together with the promoter for the zinc finger RNA binding protein (ZFR) gene onchromosome 1, is strongly associated with sex dimorphism in gene expression. Except for this, we found few differences inpromoter DNA-methylation, even though hundreds of genes were robustly differentially expressed across distantly relatedbreeds. Several of the differentially expressed genes are known to affect behavior, and as suggested from their functionalannotation, we found that female Red Junglefowl are more explorative and fearful in a range of tests performed throughouttheir lives. This paper identifies new sites and, with increased resolution, confirms known sites where DNA-methylationseems to affect sexually dimorphic gene expression, but the general lack of this association is noticeable and strengthensthe view that birds do not have dosage compensation.
Place, publisher, year, edition, pages
Public Library of Science , 2014. Vol. 9, no 4, e96376- p.
IdentifiersURN: urn:nbn:se:liu:diva-106374DOI: 10.1371/journal.pone.0096376ISI: 000335504900030OAI: oai:DiVA.org:liu-106374DiVA: diva2:715685