TThe zebrafish (Danio rerio) is a popular model for vertebrate development and genetics, due to its ease of maintenance, the ability to observe developmental aberrations in the early embryo, and the simplicity of mutagenesis techniques. The Hogan and Smith labs at IMB are conducting forward genetic screens using ENU-mutagenised zebrafish to understand the genetics of lymphangiogenesis and cardiovascular development, respectively. Traditional mapping techniques to identify causative mutations – using microsatellite markers to identify the region of interest, followed by resequencing of candidate genes – are laborious and time-consuming. New approaches have been developed recently which employ whole-genome sequencing using the Illumina platform. I will present results of the mutants we have characterised using these methods, including the successful identification of several novel genes involved in lymphangiogenesis and cardiovascular development, and modifications we have made to reduce sequencing costs.