The POU proteins BRN-3a, -3b and -3c are transcription factors encoded by separate genes that are differentially expressed during neural development. Comparison of genomic and cDNA sequences revealed similar exon/intron structures for Brn-3a and -3c genes, whereas the Brn-3b gene appeared to contain an intronless coding region. Fluorescence in situ hybridization experiments with mouse chromosomes showed that Brn-3a maps to mouse chromosome 14E1-3, Brn-3b to XF1-5 and Brn-3c to 18B3-E1.