Comparison of the gene expression expression profile of activated and resting epicardium

Zebrafish can regenerate their hearts. As a first response to injury, the epicardium reacts by upregulalion of developmental marker genes. Here we compared in an unbiased manner the expression of the epicardium from uninjured zebrafish hearts and hearts at 3 days postcryoinjury. To label epicardial cells of uninjured hearts we usd pard3:GFP (POon et al 2010) and to label epicardium of the injured heart wt1b:eGFP (Perner et al 2007) GFP positive cells were FAC sorted from uninjured pard3:GFP adult zebrafish hearts and wt1b:eGFP hearts 3 days postinjury (dpi). RNA was extracted from 4 pools of pard3:GFP and 4 pools of wt1b:eGFP cells. Each pool contained GFP positive cells isolated from 15 pard3:GFP hearts or 3 wt1b:eGFP hearts, respectively .