Nurr1 has been recently found to be critical for the development and maintenance of mesencephalic dopamine (DA) neurons.To uncover the molecular mechanisms by which Nurr1 contributes to the development of DA neurons,we have applied zebrafish to study the topographic distribution of nurr1 transcripts during the early embryogenesis because of its ectogenesis and transparent,as well as its correlation with neuron progenitor marker (ngn 1) and DA neuron markers(tyrosine hydroxylase,TH and DA transporter,DAT).Our studies show that although nurrl transcripts did not co-localize with TH and DAT transcripts in the basal forebrain,it partially co-expressed with ngnl in the region before 36 hpf.