Further Characterization Of A Highly Conserved Novel Meis2 Linked Gene And Protein Product

We have identified a novel gene linked to the Meis2 gene (meis2.2 in zebrafish) in all vertebrates. This gene is always located immediately downstream of Meis2 (meis2.2 in zebrafish) and is organized in an inverted convergently-transcribed manner. Transcripts of this gene are maternally expressed ubiquitously at high levels during early zebrafish development with the highest level of expression at fertilization. The zygotic genome produces transcripts of this gene again around 12 hpf and low levels of expression are then localized to the developing neural tube and retina at 48 hpf. We have shown that the gene is translated into protein within the developing embryo and that it is expressed at various stages throughout development. Western blots show that the protein is expressed as early as 2 hpf and is present in significant amounts until 24 hpf, at which point its expression is significantly decreased. Immunohistochemistry on 48 hpf zebrafish embryo cross-sections show that the protein is present and is highly localized to the optic area, as well as the olfactory bulb and epithelium. IHC hybridization on embryos 24 hpf and 48 hpf reveals localized expression the developing olfactory bulb and epithelium along with the optic cup and brain.