Zebrafish research in Greece: swimming against the current.

The zebrafish is a vertebrate model extensively used in Developmental Biology and Human Disease modeling, as it shares high genetic and physiological similarities with humans. It has become the second most popular animal model, after mice, with several advantages over the latter: zebrafish are easily housed and cared for; the cost of installing and maintaining a zebrafish facility is significantly lower than for mice; and they reproduce often and develop quickly. Using zebrafish complies with the 3Rs principles of laboratory animal use. Zebrafish embryos develop externally and are transparent, allowing for in vivo non-invasive imaging. There are many transgenic and mutant lines available that mimic most human diseases, including reporter lines for most signaling pathways. There are also several reverse genetic tools to functionally verify genes or variants of unknown significance, identified in Genome-Wide Association Studies (GWAS) or using Next Generation Sequencing (NGS) approaches. In addition, the model emerges as an invaluable whole animal platform for various stages of drug discovery efforts by exploring the possibility of creating high-throughput phenotypic-driven screens. These include phenotypic screenings, determinations of general and/or specific toxicity (cardiac, renal, hepatotoxicity etc.), and mechanism of action studies. Finally, zebrafish are able to retain their capacity to regenerate most organs during their entire life span, making them a well-established model for the study of organ regeneration. The European Zebrafish Society consists of more than 180 research labs throughout Europe. In Greece however, zebrafish use remains rather limited. Here I present here a brief historical overview of zebrafish research in Greece.