Cell migration in organisms is a complicated process, which is accomplished by the finetuned activity of the cytoskeleton in different regions of the cell. In vertebrates, cell migration plays a fundamental role as the three dimensional structure of organs is built by the migration of many different cell types: for example during the development of the nervous system and the blood vessels. It is obvious that these movements of cells from different origins have to be coordinated to ensure that each cell reaches its destined place. However, very little is known about how an embryo manages this huge logistic task. Embryos of the zebrafish, Danio rerio
, harbour many characteristics making them the ideal model organism to study this dynamic cell behaviour in vivo
: The embryos develop extremly fast outside the mother organism: 24 hours post fertilisation all important organ systems have started to form. Moreover, fish embryos are transparent, allowing high resolution time lapse microscopy to study and examine living animals.