Thanks be to Zebrafish

Abstract

During the last 10–15 years, the tiny, tropical, freshwater zebrafish has become one of the most powerful and versatile models for studying vertebrate heart development. Three recent reports in Nature remind us of just how much we owe to this fishy friend of research. The zebrafish was first developed for use as a model organism by George Streisinger at the University of Oregon in the 1970s. A common resident of household tropical aquariums, the fish soon became a common laboratory resident thanks to its hardiness and many other research-friendly characteristics. The zebrafish is small, easy to keep, and produces large numbers of offspring on a regular basis—female zebrafish can produce up to 200 eggs per week. Such features make it perfect for genetic analysis. Its genome has been fully sequenced, large-scale mutation screenings have been carried out, and countless transgenic strains and human disease models are available. In addition, the zebrafish embryo is transparent, develops rapidly, and grows externally from the mother, allowing for easy experimental manipulation and observation. The zebrafish is, thus, close to being the ideal model organism for studying vertebrate development. In the field of cardiovascular biology, studies of zebrafish heart development have revealed a large number of genes and pathways that are conserved with higher vertebrates and mammals. Thus, although the zebrafish is coldblooded and its heart has just a single ventricle, it serves as a great tool and starting point for comparative analysis. One feature of the zebrafish heart that differs dramatically from that of mammals is the capacity for regeneration. In 2002, Kenneth Poss (Duke University, Durham, NC) and colleagues reported in the journal Science that after removing up to 20% of the fish's ventricle, the heart could regrow fully.1 This led to the exciting idea that if scientists could discover how the …