Expression patterns of prune2 is regulated by Notch and retinoic acid signaling pathways in the zebrafish embryogenesis.

PRUNE2 has been identified as a susceptible gene for Alzheimer's disease and a marker for leiomyosarcomas. Isoforms of Prune2 regulate neuronal cell differentiation and synaptogenesis. Although expression pattern of Prune2 has been reported in the murine brain, its expression patterns and regulation along vertebrate embryogenesis remain to be further investigated. We thus defined the expression profiles and transcriptional regulation of prune2 in zebrafish embryos. prune2 exhibits maternal expression, but is increased in later embryonic stages, and expressed in the telencephalon, epiphysis cluster, nucleus of the tract of the post optic commissure, spinal cord, cerebellum, tegmentum, anterior lateral line ganglion, posterior lateral line ganglion and rhombomeres 2 through 5. Two color WISH with a post-mitotic neuron specific marker, huC defined that prune2 is expressed in the post mitotic neurons. The level of prune2 transcripts is upregulated in Notch signaling homozygous mutant, mib1-/-(mibta52b), indicating that Notch signaling regulates transcription of prune2. Interestingly, in silico analysis of prune2 promoter found retinoic acid (RA) response elements (AGGTCAcaTGACCA) located at -3 to -16 relative to the first exon. It turned out that RA signaling altered the expression pattern of prune2 in the hindbrain. We further propose that Prune2 might be a putative regulator for CNS development in zebrafish embryogenesis.