||Brd2 is a member of the bromodomain-containing BET family of transcriptional co-regulators and is known to induce or repress transcription. The Drosophila homolog fs(1)h is known to control homeotic gene expression during development. In zebrafish, reduced levels of Brd2 result in morphological abnormalities at the midbrain-hindbrain boundary (MHB). RNA in situ hybridization was performed to assay for homeotic gene expression patterns in Brd2 morpholino knockdown zebrafish embryos. Engrailed2a , a target of the Brd2 homolog in Drosophila showed reduced expression in specifically the hindbrain portion of the MHB in Brd2-morphants. Pax2a was also reduced in the hindbrain, suggesting that the hindbrain portion of the MHB is improperly specified when Brd2 is deficient. Krox20 expression is reduced in the third rhombomere, further suggesting improper specification of the hindbrain. This study is the first to show that the Brd2/homeotic regulatory pathway is conserved in vertebrates and is likely required for proper brain development.