Dgcr8 function in the anterior second heart field

Morphogenesis of the heart is a complex process that relies on the precise gene expression and gene expression regulators during embryonic development. Dgcr8 is a gene involved in cardiac morphogenesis and it is in the chromosomal region deleted in 22q11.2DS patients. In order to study Dgcr8 function on heart development, we inactivated this gene in the cardiac progenitor cells of mouse embryos and did expression profiling of the long RNAs and miRNAs. We used microarrays to detail the global programme of gene expression downstream of DGCR8 underlying cardiac development. Mouse embryos were used at embryonic day E9.5 to microdisect two different cardiac tissues, the cardiac progenitor cells located at the back of the heart tube (aSHF) and the outflow tract and right ventricle (OFT-RV) from the heart tube itself. Several pools of each tissue from wild type or mutants embryos were processed for RNA extraction and hybridization on Affymetrix microarrays. We sought to obtain pools combining several embryos of the same genotype per replicate in order to obtain a more accurate representation of the expression profile in the embryo population. To that end, we have pooled embryos of the same genotype from at least five different litters. Thirty different pools were obtained, one per array described in the sample list.