title: Differential requirements for neurogenin 3 in the development of POMC and NPY neurons in the hypothalamus.
abstract: The neuroendocrine hypothalamus regulates a spectrum of essential biological processes and underlies a range of diseases from growth failure to obesity. While the exploration of hypothalamic function has progressed well, knowledge of hypothalamic development is poor. In particular, very little is known about the processes underlying the genesis and specification of the neurons in the arcuate and ventromedial nuclei. Recent studies demonstrate that the proneural basic helix-loop-helix transcription factor Mash1 is required for neurogenesis and neuronal subtype specification in the ventral hypothalamus. We demonstrate here that Ngn3, another basic helix-loop-helix transcription factor, is expressed in mitotic progenitors in the arcuate and ventromedial hypothalamic regions of mouse embryos from embryonic days 9.5-17.5. Genetic fate mapping and loss of function studies in mice demonstrate that Ngn3+ progenitors contribute to subsets of POMC, NPY, TH and SF1 neurons and is required for the specification of these neuronal subtypes in the ventral hypothalamus. Interestingly, while Ngn3 promotes the development of arcuate POMC and ventromedial SF1 neurons, it inhibits the development of NPY and TH neurons in the arcuate nuclei. Given the opposing roles of POMC and NPY neurons in regulating food intake, these results indicate that Ngn3 plays a central role in the generation of neuronal populations controlling energy homeostasis in mice.
authors.affiliation: Division of Developmental Neurobiology, MRC National Institute for Medical Research, The Ridgeway, London, NW7 1AA, UK.
authors.forename: Michelle
authors.initials: M
authors.lastname: Pelling
authors.forename: Neal
authors.initials: N
authors.lastname: Anthwal
authors.forename: David
authors.initials: D
authors.lastname: McNay
authors.forename: Gerard
authors.initials: G
authors.lastname: Gradwohl
authors.forename: Andrew B
authors.initials: AB
authors.lastname: Leiter
authors.forename: Francois
authors.initials: F
authors.lastname: Guillemot
authors.forename: Siew-Lan
authors.initials: SL
authors.lastname: Ang
mesh_terms: D000818:Animals; D051792:Basic Helix-Loop-Helix Proteins / Q000235:genetics / Q000378:metabolism*; D004734:Energy Metabolism / Q000235:genetics / Q000502:physiology*; D007031:Hypothalamus / Q000196:embryology*; D007150:Immunohistochemistry; D017403:In Situ Hybridization; D007211:Indoles; D051379:Mice; D018345:Mice, Knockout; D009419:Nerve Tissue Proteins / Q000235:genetics / Q000378:metabolism*; D055495:Neurogenesis / Q000235:genetics / Q000502:physiology*; D009474:Neurons / Q000378:metabolism*; D009478:Neuropeptide Y / Q000378:metabolism; D011333:Pro-Opiomelanocortin / Q000378:metabolism
chemical_list: D051792:Basic Helix-Loop-Helix Proteins; D007211:Indoles; D009419:Nerve Tissue Proteins; D009478:Neuropeptide Y; D011333:Pro-Opiomelanocortin; C407737:Neurog3 protein, mouse; C007293:DAPI