title: Hox Genes Promote Neuronal Subtype Diversification through Posterior Induction in Caenorhabditis elegans.
abstract: Although Hox genes specify the differentiation of neuronal subtypes along the anterior-posterior axis, their mode of action is not entirely understood. Using two subtypes of the touch receptor neurons (TRNs) in C. elegans, we found that a "posterior induction" mechanism underlies the Hox control of terminal neuronal differentiation. The anterior subtype maintains a default TRN state, whereas the posterior subtype undergoes further morphological and transcriptional specification induced by the posterior Hox proteins, mainly EGL-5/Abd-B. Misexpression of the posterior Hox proteins transformed the anterior TRN subtype toward a posterior identity both morphologically and genetically. The specification of the posterior subtype requires EGL-5-induced repression of TALE cofactors, which antagonize EGL-5 functions, and the activation of rfip-1, a component of recycling endosomes, which mediates Hox activities by promoting subtype-specific neurite outgrowth. Finally, EGL-5 is required for subtype-specific circuit formation by acting in both the sensory neuron and downstream interneuron to promote functional connectivity.
authors.affiliation: Department of Biological Sciences, Columbia University, New York, NY 10027, USA.
authors.forename: Chaogu
authors.initials: C
authors.lastname: Zheng
authors.affiliation: Department of Biological Sciences, Columbia University, New York, NY 10027, USA.
authors.forename: Margarete
authors.initials: M
authors.lastname: Diaz-Cuadros
authors.affiliation: Department of Biological Sciences, Columbia University, New York, NY 10027, USA. Electronic address: mc21@columbia.edu.
authors.forename: Martin
authors.initials: M
authors.lastname: Chalfie
mesh_terms: D000818:Animals; D030801:Animals, Genetically Modified; D017173:Caenorhabditis elegans / Q000235:genetics* / Q000254:growth & development*; D029742:Caenorhabditis elegans Proteins / Q000235:genetics*; D005801:Genes, Homeobox / Q000235:genetics*; D018398:Homeodomain Proteins / Q000235:genetics*; D007395:Interneurons / Q000502:physiology*; D009154:Mutation / Q000235:genetics; D011984:Sensory Receptor Cells / Q000502:physiology*; D014157:Transcription Factors / Q000235:genetics*
chemical_list: D029742:Caenorhabditis elegans Proteins; C477318:Egl-5 protein, C elegans; D018398:Homeodomain Proteins; D014157:Transcription Factors