title: Neuregulin-3 regulates epithelial progenitor cell positioning and specifies mammary phenotype.
abstract: Mutation of Neuregulin-3 (Nrg3) results in defective embryonic mammary gland development. Here, we investigate functions of Nrg3 signaling in embryonic mammary morphogenesis. Nrg3 regulates the distribution of epithelial progenitor cells within the presumptive mammary-forming region during early mammary morphogenesis. Basal and suprabasal epithelial cells are significantly smaller within the hypoplastic mammary primordium (MP) that forms in Nrg3 mutants, indicative of failure to acquire mammary epithelial cell (MEC) morphological phenotype. Activation of Erbb4 JM-a CYT-1, an Erbb4 isoform expressed in the developing MP, leads to MEC spreading and migration. Nrg3 promotes the accumulation of epithelial progenitor cells at the MP site in embryo explant cultures. Our results implicate Nrg3 signaling in mediating key events of mammary mesenchyme specification, including mesenchymal condensation, mitosis, and induction of mammary marker expression. Taken together, our results show Nrg3 has a major role in conferring specification of the mammary phenotype to both epithelial and mesenchymal progenitor cells.
authors.affiliation: Division of Breast Cancer Research, Breakthrough Breast Cancer Research Centre, The Institute of Cancer Research , London, United Kingdom .
authors.forename: Naoko
authors.initials: N
authors.lastname: Kogata
authors.forename: Erik
authors.initials: E
authors.lastname: Oliemuller
authors.forename: Olivia
authors.initials: O
authors.lastname: Wansbury
authors.forename: Beatrice A
authors.initials: BA
authors.lastname: Howard
mesh_terms: D000818:Animals; D002454:Cell Differentiation / Q000502:physiology; D002460:Cell Line; D004847:Epithelial Cells / Q000378:metabolism / Q000502:physiology*; D005260:Female; D006801:Humans; D047908:Intracellular Signaling Peptides and Proteins / Q000378:metabolism*; D008321:Mammary Glands, Animal / Q000378:metabolism / Q000502:physiology*; D042361:Mammary Glands, Human / Q000378:metabolism / Q000502:physiology*; D008648:Mesoderm / Q000378:metabolism / Q000502:physiology; D051379:Mice; D009024:Morphogenesis / Q000502:physiology; D020880:Neuregulins / Q000378:metabolism*; D010641:Phenotype; D020033:Protein Isoforms / Q000378:metabolism; D066247:Receptor, ErbB-4 / Q000378:metabolism; D015398:Signal Transduction / Q000502:physiology; D013234:Stem Cells / Q000378:metabolism / Q000502:physiology*
chemical_list: D047908:Intracellular Signaling Peptides and Proteins; D020880:Neuregulins; D020033:Protein Isoforms; D066247:Receptor, ErbB-4