Comparison of tbx5-positive ventricular cardiomyoctes with the rest of ventricular cardiomyocytes from adult zebrafish hearts. Danio rerio

In vertebrates, the heart has two main layers of cardiac muscle, a peripheral compact layer and an internal trabecular layer. Little is known on the differerences in gene expression between both layers. In zebrafish the outer layer is named cortical layer and the internal also trabecular layer. Here we used a double transgenic line labelling with GFP tbx5-positive cells and cardiomyoctes with nuclear DsRed (nucDsRed) to distinguish cortical from trabecular myocardium. Then, we compared the transcriptome of trabecular and cortical myocardium in the adult zebrafish. We describe that Tbx5a is a good marker of trabecular myocardium. Overall design: Four paired biological replicates consisting on Tbx5-positive and Tbx5-negative adult zebrafish ventricular cardiomyocytes were analysed by RNA-seq to compare their transcriptomic profiles.

在脊椎动物（vertebrates）中，心脏拥有两层主要的心肌结构：外周致密层（peripheral compact layer）与内部肌小梁层（internal trabecular layer）。目前学界对这两层心肌的基因表达差异尚知之甚少。在斑马鱼（zebrafish）中，外层被命名为皮质层（cortical layer），内层同样属于肌小梁层（trabecular layer）。本研究采用同时标记tbx5阳性细胞的绿色荧光蛋白（GFP）与核定位DsRed（nucDsRed）的双转基因品系（double transgenic line），以区分皮质层与肌小梁层心肌组织。随后，我们对成年斑马鱼的肌小梁层与皮质层心肌组织进行了转录组对比分析。本研究证实Tbx5a可作为肌小梁层心肌的优质标记物。整体实验设计：本研究通过RNA测序（RNA-seq）分析了4组配对生物学重复（paired biological replicates）样本，样本均取自成年斑马鱼心室的tbx5阳性与tbx5阴性心肌细胞，以对比二者的转录组特征。