Bone morphogenetic protein/retinoic acid inducible neural-specific protein (brinp) expression during Danio rerio development

Prototype Membrane Attack Complex/Perforin (MACPF) superfamily proteins such as complement and perforin play crucial roles in immune defense where they drive lytic pore formation. However, it is evident that other MACPF family members are important in the central nervous system. For example, three bone morphogenetic protein/retinoic acid inducible neural-specific proteins (Brinp1, Brinp2 and Brinp3) are present in developing and mature mammalian neurons, but their molecular function is unknown. In this study we have identified and cloned full-length orthologues of all three human brinps from Danio rerio (zebrafish). Zebrafish and human brinps show very high sequence conservation, and the chromosomal loci are syntenic. We also identified two additional brinp3 paralogues at a separate locus in the zebrafish genome. The spatiotemporal expression of all five zebrafish brinps was determined by RT-PCR and whole mount RNA in situ hybridisation. Each brinp is expressed broadly in the developing nervous system at early stages (24 hours post fertilisation), but localises to specific structures in older embryos (48-72 hpf), as has been reported in mice. The conserved structures and spatiotemporal expression patterns of brinps reported in this study suggest that zebrafish will be useful for generating loss of function phenotypes to assist in determining the molecular role of these proteins.