Using an induction gene trap approach with bFGF, we identified a novel mouse gene mbFZb (mouse basic FGF repressed, putative Zic binding protein). It shows high homology to a putative Zic3 binding protein in Xenopus (AF129131). We used the in situ hybridization technique on sections to analyze the expression pattern of mbFZb during embryonic development in the mouse. From E9.5 onwards it is expressed mainly in the developing nervous system, with high levels of expression in the proliferating neuroepithel of the brain and the neural tube, the ganglia of the cranial nerves V, VII, VIII, IX and X and the dorsal root ganglia. MbFZbtranscript can also be detected in the developing eye and the brown fat. In the adult brain strong expression is restricted to the olfactory bulb, the hippocampus, the piriform cortex and the Purkinje cells of the cerebellum. On the cellular level the mbFZb/GFP fusion protein is localized in vesicular structures in the cytoplasm.