During development transcriptional and posttranscriptional networks are coordinately regulated to drive organ maturation, tissue formation, and cell fate. Interestingly, more than 90% of the human genes undergo alternative splicing, a posttranscriptional mechanism that explains how one gene can give rise to multiple protein isoforms. Heart and skeletal muscle are two of the tissues where the most tissue specific splicing takes place raising the question of how developmental stage- and tissue-specific splicing influence protein function and how this regulation occurs. In my lab we are interested on two exciting aspects of this broad question: i) how alternative splicing of trafficking and membrane remodeling genes contributes to muscle development, structure, and function, ii) the coupling between epigenetics and alternative splicing in postnatal heart development.