title: Expression of prion gene and presence of prion protein during development of mouse molar tooth germ.
abstract: In order to gain insight into possible cellular functions of the prion protein (PrP) during normal development, the expression of Prnp (encoding the PrP) and the distribution of the PrP were studied in murine tooth germs. Expression of Prnp in the mouse first molar tooth germ was highly dynamic, increasing several-fold during the secretory phase of odontogenesis, exhibiting a time-course of expression similar to that of genes coding for other extracellular proteins [e.g. enamel matrix proteins (Amelx, Ambn, Enam), Aplp1, Clstn1, and Clu]. Western blot analysis suggested that the amounts of PrP and amyloid beta (A4) precursor-like protein 1 (APLP1) in the tooth germ followed time-courses similar to those of the corresponding mRNAs. Immunohistochemical studies of the distribution of PrP in murine molar and incisor tooth germs at embryonic day (E)18.5 suggested that this protein was located in the cervical loop, outer enamel epithelium, pre-ameloblasts, and dental papilla. Different degrees of immunolabelling of pre-ameloblasts on the mesial and distal aspects of a lower molar cusp may be related to different enamel configurations on the two aspects. It is concluded that the dynamic patterns of expression of Prnp, and of distribution of PrP, suggest that PrP may have functions during secretory odontogenesis, perhaps in relation to amelogenesis.
authors.affiliation: Department of Oral Biology, University of Oslo, Oslo, Norway. qsahmed@odont.uio.no
authors.forename: Qalb-E-Saleem
authors.initials: QE
authors.lastname: Khan
authors.forename: Charles McL
authors.initials: CM
authors.lastname: Press
authors.forename: Amer
authors.initials: A
authors.lastname: Sehic
authors.forename: Maria A
authors.initials: MA
authors.lastname: Landin
authors.forename: Steinar
authors.initials: S
authors.lastname: Risnes
authors.forename: Harald
authors.initials: H
authors.lastname: Osmundsen
mesh_terms: D048868:Adaptor Proteins, Signal Transducing / Q000032:analysis; D000565:Ameloblasts / Q000166:cytology; D000566:Amelogenesis / Q000235:genetics / Q000502:physiology; D053523:Amelogenin / Q000032:analysis; D016564:Amyloid beta-Protein Precursor / Q000032:analysis; D000818:Animals; D000831:Animals, Newborn; D015153:Blotting, Western; D002135:Calcium-Binding Proteins / Q000032:analysis; D051152:Clusterin / Q000032:analysis; D003743:Dental Enamel / Q000196:embryology; D003746:Dental Enamel Proteins / Q000032:analysis; D003771:Dental Papilla / Q000196:embryology; D004848:Epithelium / Q000196:embryology; D018507:Gene Expression Regulation, Developmental / Q000235:genetics; D005865:Gestational Age; D007150:Immunohistochemistry; D007180:Incisor / Q000196:embryology; D051379:Mice; D008815:Mice, Inbred Strains; D008963:Molar / Q000196:embryology*; D009419:Nerve Tissue Proteins / Q000032:analysis; D009805:Odontogenesis / Q000235:genetics / Q000502:physiology*; D020411:Oligonucleotide Array Sequence Analysis; D000072002:Prion Proteins; D011328:Prions / Q000032:analysis / Q000235:genetics*; D014083:Tooth Germ / Q000196:embryology*
chemical_list: D048868:Adaptor Proteins, Signal Transducing; C490890:Ambn protein, mouse; D053523:Amelogenin; C507200:Amelx protein, mouse; D016564:Amyloid beta-Protein Precursor; C513072:Apba1 protein, mouse; C078201:Aplp1 protein, mouse; D002135:Calcium-Binding Proteins; C503227:Clstn1 protein, mouse; C495243:Clu protein, mouse; D051152:Clusterin; D003746:Dental Enamel Proteins; D009419:Nerve Tissue Proteins; D000072002:Prion Proteins; D011328:Prions; C512657:Prnp protein, mouse; C038456:tuftelin