Learning from Fish: Thymus Development in the Zebrafish

The thymus is a primary lymphoid organ whose function is to provide mature and self-tolerant T lymphocytes required to fight infection and maintain tissue integrity. About 40 mutant zebrafish lines with aberrant thymus development have been established. The mutant genes so far identified show that the zebrafish model is an excellent tool to define novel genetic pathways important for T cell development. Live imaging analysis with these mutants and novel transgenic fish lines is used to examine the genetic basis of essential steps of thymopoiesis and to unravel their spatial and temporal characteristics.