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.心脏形态发生是一个高度复杂的生物学过程，依赖于胚胎发育阶段精准的基因表达与基因表达调控因子。Dgcr8是一种参与心脏形态发生的基因，其所在的染色体区域在22q11.2缺失综合征（22q11.2DS）患者中发生缺失。为探究Dgcr8在心脏发育中的功能，我们在小鼠胚胎的心脏祖细胞中条件性敲除了该基因，并对长链RNA与微小RNA（miRNAs）进行表达谱分析。我们利用基因芯片（microarrays）解析了心脏发育过程中DGCR8下游的全局基因表达程序。我们选取胚胎发育第9.5天（E9.5）的小鼠胚胎，通过显微解剖分离出两种不同的心脏组织：分别为位于心管后方的心脏祖细胞（aSHF），以及心管自身的流出道与右心室（OFT-RV）。我们将野生型或突变体胚胎的每种组织制备为多个混合样本，用于RNA提取并在Affymetrix基因芯片上完成杂交。为更精准地反映胚胎群体的表达谱特征，我们在每个生物学重复中混合多个同基因型的胚胎；为此，我们从至少5个不同的产仔窝中收集同基因型的胚胎进行混合。最终共获得30个独立的混合样本，对应样本列表中描述的每一张芯片。