title: The -216- to -100-bp Sequence in the 5'-Flanking Region of the Oxytocin Gene Contains a Cell-Type Specific Regulatory Element for its Selective Expression in Oxytocin Magnocellular Neurones.
abstract: The oxytocin (OXT) gene is abundantly and highly selectively expressed in magnocellular neurones (MCNs) of the hypothalamic-neurohypophysial system. Previous DNA sequence deletion studies in vivo have shown that the -216- to -100-bp sequence in the 5'-flanking region of the oxytocin gene was required for its cell-type specific expression in the rat supraoptic nucleus. In the present study, we test the coupled hypotheses that this -216- to -100-bp sequence is responsible for (i) the selective expression of the OXT gene in OXT-MNCs and (ii) its selective repression in vasopressin (AVP)-MCNs. We show that, consistent with hypothesis 1, removal of the -216- to -100-bp sequence from the OXT gene completely eliminates its expression in OXT-MCNs in vivo but, in contrast to the prediction of hypothesis 2, there was no appearance of OXT gene expression in AVP-MCNs. Taken together, these and other data demonstrate that the -216- to -100-bp sequence in the 5'-flanking region of the oxytocin gene contains only an activator of transcription operating in the OXT-MCNs.
authors.affiliation: Laboratory of Neurochemistry, National Institute of Neurological Disorders and Stroke, National Institutes of Health, Bethesda, MD, USA.
authors.forename: R L
authors.initials: RL
authors.lastname: Fields
authors.affiliation: Laboratory of Neurochemistry, National Institute of Neurological Disorders and Stroke, National Institutes of Health, Bethesda, MD, USA.
authors.forename: H
authors.initials: H
authors.lastname: Gainer
mesh_terms: D000818:Animals; D015870:Gene Expression / Q000502:physiology*; D008297:Male; D009474:Neurons / Q000378:metabolism*; D010121:Oxytocin / Q000235:genetics*; D051381:Rats; D017207:Rats, Sprague-Dawley; D013495:Supraoptic Nucleus / Q000378:metabolism*; D014667:Vasopressins / Q000378:metabolism*
chemical_list: D014667:Vasopressins; D010121:Oxytocin
keywords: enhancer; gene expression; hypothalamus; magnocellular neurone; oxytocin; repressor; supraoptic nucleus; vasopressin