Punnamoottil, B., Kikuta, H., Pezeron, G., Erceg, J., Becker, T.S., and Rinkwitz, S. (2008) Enhancer detection in zebrafish permits the identification of neuronal subtypes that express Hox4 paralogs. Developmental dynamics : an official publication of the American Association of Anatomists. 237(8):2195-2208.
Activity of zebrafish hoxb4a in the developing brain was analyzed in comparison to hoxa4a and hoxd4a using unique enhancer detection transgenes. Cytoplasmic YFP revealed shape and axonal projections of neurons in animals with insertions near the Hox4 genes and provided a means for the identification of neuronal subtypes. Despite an early activity of the genes in neuroepithelial cells and later in immature postmitotic neurons, we found reporter expression in distinct neuronal subtypes in the r7-r8-derived hindbrain. Most strikingly, hoxb4a neuronal subtypes projected through the vagus and into the pectoral fin while others formed symmetrically located fiber tracts innervating the cerebellum and the tectum, features that are partially shared by the other two paralogs. Collectively, our expression analysis indicates that hoxb4a in combination with its paralogs may play a significant role in the development of precerebellar, vagal, and pectoral fin neuronal subtypes.
Erratum in: Developmental Dynamics, 09/24/2008, 237(10):3098 In the original published version of this article, the Results section contained a numerical error. The sentence reading, Mapping of the retroviral insertion 3 kb downstream of hoxb4a was described previously (Hadrys et al., 2006). was incorrect. The correct sentence should read, Mapping of the retroviral insertion 0.6 kb downstream of hoxb4a was described previously (Hadrys et al., 2006). The authors regret this error.