1097-6256612003JanNat NeurosciZinc finger protein too few controls the development of monoaminergic neurons.283328-33The mechanism controlling the development of dopaminergic (DA) and serotonergic (5HT) neurons in vertebrates is not well understood. Here we characterized a zebrafish mutant--too few (tof)--that develops hindbrain 5HT and noradrenergic neurons, but does not develop hypothalamic DA and 5HT neurons. tof encodes a forebrain-specific zinc finger transcription repressor that is homologous to the mammalian Fezl (forebrain embryonic zinc finger-like protein). Mosaic and co-staining analyses showed that fezl was not expressed in DA or 5HT neurons and instead controlled development of these neurons non-cell-autonomously. Both the eh1-related repressor motif and the second zinc finger domain were necessary for tof function. Our results indicate that tof/fezl is a key component in regulating the development of monoaminergic neurons in the vertebrate brain.LevkowitzGilGRinat Neuroscience Corporation, 3155 Porter Drive, Palo Alto, California 94304, USA. gillev@rinatneuro.comZellerJörgJSirotkinHoward IHIFrenchDorothyDSchilbachSarahSHashimotoHisashiHHibiMasahikoMTalbotWilliam SWSRosenthalArnonAengRR12349RRNCRR NIH HHSUnited StatesJournal ArticleResearch Support, Non-U.S. Gov'tResearch Support, U.S. Gov't, P.H.S.