Cell-Specific Expression and Subcellular Localization of Neurophysin-CAT-Fusion Proteins Expressed from Oxytocin and Vasopressin Gene Promoter-Driven Constructs in Transgenic Mice

• Published in: Experimental neurology Vol. 171; no. 2; pp. 255 - 271
• Main Authors: Jeong, S-W., Castel, M., Zhang, B-J., Fields, R.L., Paras, P., Arnheiter, H., Chin, H., Gainer, H.
• Format: Journal Article Conference Proceeding
• Language: English
• Published: Amsterdam Elsevier Inc 01.10.2001; Elsevier
• Subjects: Amygdala - metabolism; Animals; Biochemistry and metabolism; Biological and medical sciences; Central nervous system; Chloramphenicol O-Acetyltransferase - analysis; Chloramphenicol O-Acetyltransferase - genetics; Exons; Fundamental and applied biological sciences. Psychology; gene expression; Gene Expression Regulation - physiology; Genes, Reporter; Gyrus Cinguli - metabolism; hypothalamus; magnocellular neurons; Mice; Mice, Transgenic; Microscopy, Immunoelectron; Neurophysins - analysis; Neurophysins - genetics; oxytocin; Oxytocin - genetics; Paraventricular Hypothalamic Nucleus - cytology; Paraventricular Hypothalamic Nucleus - metabolism; Paraventricular Hypothalamic Nucleus - ultrastructure; protein trafficking; Recombinant Fusion Proteins - analysis; Recombinant Fusion Proteins - biosynthesis; Supraoptic Nucleus - cytology; Supraoptic Nucleus - metabolism; Supraoptic Nucleus - ultrastructure; transgenic mice; vasopressin; Vasopressins - genetics; Vertebrates: nervous system and sense organs; oxytocin; protein trafficking; transgenic mice; vasopressin; magnocellular neurons; hypothalamus; gene expression; Oxytocin; Peptide hormone; Rodentia; Transgenic animal; Neurophysin; Gene expression; Neuropeptide; Vasopressin; Vertebrata; Mammalia; Exon; Intron; Mouse; Neurohypophyseal hormone; Comparative study
• ISSN: 0014-4886; 1090-2430
• DOI: 10.1006/exnr.2001.7785

The cell-specific expression of both the oxytocin (OT) and vasopressin (VP) genes in magnocellular neurons (MCNs) of the hypothalamus has been proposed to be under the control of cis-elements in an intergenic region downstream of the VP gene. We examined this hypothesis using transgenic mice containing mouse genomic DNA-derived constructs linked to chloramphenicol acetyltransferase (CAT) reporters. VP gene expression was studied using constructs containing 3.8 kbp of the 5′ flanking region and all the exons and introns in the mouse VP gene, which was fused at the end of exon 3 to a CAT reporter. The two VP-transgene constructs differed by the lengths of their VP gene 3′ flanking regions (2.1 versus 3.6 kbp). A similar construct for the oxytocin CAT transgene was used which contained the full-length (3.6 kbp) downstream intergenic region between the mouse genes. All three transgenic constructs produced cell-specific expression of the CAT-reporter in the magnocellular neurons as determined by CAT-immunoreactivity. Oxytocin transgene expression was restricted to OT cells in two founders, and the two VP transgenes to VP cells in five founders. Electron microscopic immunocytochemistry showed that the CAT fusion proteins produced from the OT- and VP-transgenes were efficiently trafficked through the regulated secretory pathways in their respective magnocellular neurons, packaged into large dense core vesicles, and transported to nerve terminals in the posterior pituitary.