FEATURE The stars of biomedicine Zebrafish are easy to breed, transparent and their eggs develop outside the body of the mother, allowing researchers to observe embryonic development without harming adult animals. Perhaps most importantly, many of their genes are identical to those of humans. This all makes the zebrafish, Danio rerio, an excellent model organism to better understand the molecular underpinnings of human diseases ranging from cancer to cardiovascular diseases, myopathy and neurodegenerative diseases. At the end of July, the biggest zebrafish repository in Europe was opened at the Karlsruhe Institute of Technology in southern germany. The European Zebrafish Resource Center (EZRC) maintains more than three thousand aquaria as well as freezers for 50,000 sperm samples. EMBO Member Christiane Nüsslein-Volhard from the Max Planck Institute for Developmental Biology in Tübingen, germany talked about her pioneering role in European zebrafish research at the opening ceremony. “The idea of conducting research on vertebrates electrified me,” remembered Nüsslein-Volhard. Until the late eighties, she had focused on analys- ing the genetic control of embryo development in Drosophila. It was only after she had heard about the research results of United States scientist george Streisinger that she also started to work on vertebrates. Streisinger, who was a professor at the University of Oregon until his death in 1984, is considered by many of his peers to be the founding father of zebrafish developmental and genetic research. “Our lab in Tübingen was among the first in Europe to work with zebrafish,” said the 1995 Nobel laureate. One of the problems her team faced was to breed fish families on a large scale. She knew from research on fruit flies that four to five thou- sand families are needed to identify the genes responsible for embryo development. Building a fish house for seven thousand aquaria in 1992 improved the situation and Nüsslein-Volhard’s group finished the screening of the mutants in only a few months. Then, her team submitted twenty-two manuscripts for a special issue of the journal Development – again, within a year. “That was a great time,” recalls the scientist. Wolfgang Driever, her former PhD student and now head of Developmental Biology at the University of Freiburg, explained in the next pres- entation why zebrafish are fascinating model organisms for neuroscientists. The striped fish have stunning regenerative skills. They are capa- ble of developing dopaminergic neurons through- out their life – unlike humans. The loss of these neurons is irreversible in human organisms – and is responsible for neurological diseases such as Alzheimer’s. In recent years, European labs have gener- ated thousands of zebrafish lines, each of which carries either a particular mutation that can serve as a model for a human disease. However, in contrast to their US colleagues, European researchers were lacking a central repository to store and distribute these fish. This role will be assumed by the EZRC in future. The institute will also function as the first zebrafish screening centre worldwide, welcoming guest researchers from all over the globe to perform systematic research on these vertebrates. The Karlsruhe Institute of Technology is an ideal location for such a centre as it offers a unique interdiscipli- nary environment combining top research in natural and engineering sciences. Top: The zebrafish Danio rerio Aquaria High throughput laboratory facility 8 EMBOencounters | Autumn 2012 | communications@embo.org ©2012 EMBO © Karlsruhe Institute of Technology (KIT) www.kit.edu