Heart development is a complex process, tightly regulated by numerous molecular mechanisms. Key components of the regulatory network underlying heart development are transcription factors (TFs) and microRNAs (miRNAs), yet limited investigation of the role of miRNAs in heart development has taken place. Here, we report the first parallel genome-wide profiling of polyadenylated RNAs and miRNAs in a developing murine heart. These data enable us to identify dynamic activation or repression of numerous biological processes and signaling pathways. More than 200 miRNAs and 25 long non-coding RNAs were differentially expressed during embryonic heart development compared to the mature heart; most of these had not been previously associated with cardiogenesis. Integrative analysis of expression data and potential regulatory interactions suggested 28 miRNAs as novel regulators of embryonic heart development representing a considerable expansion of the current repertoire of known cardiac miRNAs. To facilitate follow-up investigations, we constructed HeartMiR (http://heartmir.sysbiolab.eu), an open access database and interactive visualization tool for the study of gene regulation by miRNAs during heart development.

心脏发育是一个复杂的过程，受到众多分子机制的严格调控。心脏发育的基础调控网络的关键成分是转录因子（TF）和microRNA（miRNA），但对miRNA在心脏发育中作用的研究很少。在这里，我们报告了发展中的小鼠心脏中的聚腺苷酸化的RNA和miRNA的第一个并行全基因组分布图。这些数据使我们能够确定许多生物过程和信号传导途径的动态激活或抑制。与成熟心脏相比，在胚胎心脏发育过程中差异表达了200多个miRNA和25个长非编码RNA。其中大多数以前都没有与心脏发生有关。对表达数据和潜在调控相互作用的综合分析表明，有28种miRNA作为胚胎心脏发育的新型调节剂，代表了目前已知心脏miRNA的显着扩展。为了便于后续调查，我们构建了HeartMiR（http://heartmir.sysbiolab.eu），一个开放式访问数据库和交互式可视化工具，用于研究心脏发育过程中miRNA的基因调控。