The Nk3 or bap gene family is named after the NK3 or bagpipe (bap) gene in Drosophila, which is part of the NK or 93DE homeobox gene cluster (Jagla et al. 2001). In humans, there are also two Nk3 genes, on different chromosomes, generated by genome duplication at the base of the vertebrates. Amphioxus has a single Nk3 gene. The NK gene cluster has broken in chordates (Luke et al. 2001). Nk3 genes are usually physically adjacent to Nk4 (tin) genes.|
Jagla K, Bellard M, Frasch M (2001) BioEssays 23: 125-133.
Luke GN et al. (2001) PNAS 100:5292-5295.