To gain more insight into the development of human teeth, we characterized different compartments of impacted third molars at two developmental stages by assessing expression levels of a set of genes. We considered genes known to be essential for the development of teeth and ectomesenchyme as well as genes covering characteristic features of stemness. Molars were divided into the operculum, periodontal ligament, developing pulp and, using a new approach, the pad-like tissue beneath the developing pulp. Markers for ectomesenchyme and tooth development known from rodents were assayed by semiquantitative PCR and every compartment was assigned its own signature of gene expression. The expression of markers characteristic of stem cells pointed to multipotent features. The expression patterns found shift in the course of development underscoring the relevance of these genes involved in human tooth development. The results suggest an inherent asymmetry between the developing pulp and pad-like tissue established early in tooth development. A microarray analysis of cells derived from pad-like tissue and pulp proper was performed to obtain cues regarding the consequences of tissue diversification. Both sets of data support the validity of our new approach to the subdivision of the developing tooth, by indicating a compartment-dependent commitment of isolated cells probably due to the postulated asymmetry within the developing tooth germ.

Abbott, B.L. (2006) ABCG2 (BCRP): a cytoprotectant in normal and malignant stem cells. Clin Adv Hematol Oncol 4: 63–72.
Bendall, A.J., C. Abate-Shen (2000) Roles for Msx and Dlx homeoproteins in vertebrate development. Gene 247: 17–31.
Bunting, K.D. (2002) ABC transporters as phenotypic markers and functional regulators of stem cells. Stem Cells 20: 11–20.
Cobourne, M.T., T. Mitsiadis (2006) Neural crest cells and patterning of the mammalian dentition. J Exp Zoolog B Mol Dev Evol 306: 251–260.
Degistirici, O., C. Jaqiery, B. Schoenebeck, J. Siemonsmeier, W. Goetz, I. Martin, M. Thie (2008) Defining properties of neural crest-derived progenitor cells from the apex of human developing tooth. Tissue Eng 14: 317–330.
Gronthos, S., M. Mankani, J. Brahim, P.G. Robey, S. Shi (2000) Postnatal human dental pulp stem cells (DPSCs) in vitro and in vivo. Proc Natl Acad Sci USA 97: 13625–13630.
Harada, H., T. Toyono, K. Toyoshima, M. Yamasaki, N. Itoh, S. Kato, K. Sekine, H. Ohuchi (2002) FGF10 maintains stem cell compartment in developing mouse incisors. Development 129: 1533–1541.
Heikinheimo, K., K.J. Jee, T. Niini, Y. Aalto, R.P. Happonen, I. Leivo, S. Knuutila (2002) Gene expression profiling of ameloblastoma and human tooth germ by means of a cDNA microarray. J Dent Res 81: 525–530.
Ivanovski, S., S. Gronthos, S. Shi, P.M. Bartold (2006) Stem cells in the periodontal ligament. Oral Dis 12: 358–363.
Kawanabe, N., K. Murakami, T. Takano-Yamamoto (2006) The presence of ABCG2-dependent side population cells in human periodontal ligaments. Biochem Biophys Res Commun 344: 1278–1283.
Kerkis, I., A. Kerkis, D. Dozortsev, G.C. Stukart-Parsons, S.M. Gomes Massironi, L.V. Pereira, A.I. Caplan, H.F. Cerruti (2006) Isolation and characterization of a population of immature dental pulp stem cells expressing OCT-4 and other embryonic stem cell markers. Cells Tissues Organs 184: 105–116.
Laino, G., A. Graziano, R. d’Aquino, G. Pirozzi, V. Lanza, S. Valiante, A. De Rosa., F. Naro, E. Vivarelli, G. Papaccio (2006) An approachable human adult stem cell source for hard-tissue engineering. J Cell Physiol 206: 693–701.
Le Douarin, N.M., S. Creuzet, G. Couly, E. Dupin (2004) Neural crest cell plasticity and its limits. Development 131: 4637–4650.
Le Douarin, N.M., C. Kalcheim (1999) The Neural Crest. New York, Cambridge University Press.
Li, T.S., K. Hamano, M. Nishida, M. Hayashi, H. Ito, A. Mikamo, M. Matsuzaki (2003) CD117+ stem cells play a key role in therapeutic angiogenesis induced by bone marrow cell implantation. Am J Physiol Heart Circ Physiol 285: H931–H937.
Lin, D., Y. Huang, F. He, S. Gu, G. Zhang, Y. Chen, Y. Zhang (2007) Expression survey of genes critical for tooth development in the human embryonic tooth germ. Dev Dyn 236: 1307–1312.
Lin, Y., Z. Yan, L. Liu, J. Qiao, W. Jing, L. Wu, X. Chen, Z. Li, W. Tang, X. Zheng, W. Tian (2006) Proliferation and pluripotency potential of ectomesenchymal cells derived from first branchial arch. Cell Prolif 39: 79–92.
Liu, D., S. Yao, F. Pan, G.E. Wise (2005a) Chronology and regulation of gene expression of RANKL in the rat dental follicle. Eur J Oral Sci 113: 404–409.
Liu, H., W. Li, S. Shi, S. Habelitz, C. Gao, P. Denbesten (2005b) MEPE is downregulated as dental pulp stem cells differentiate. Arch Oral Biol 50: 923–928.
Luan, X., Y. Ito, S. Dangaria, T.G. Diekwisch (2006) Dental follicle progenitor cell heterogeneity in the developing mouse periodontium. Stem Cells Dev 15: 595–608.
Mays, R.W., W. van’t Hof, A.E. Ting, R. Perry, R. Deans (2007) Development of adult pluripotent stem cell therapies for ischemic injury and disease. Expert Opin Biol Ther 7: 173–184.
McLachlan, J.L., A.J. Smith, A.J. Sloan, P.R. Cooper (2003) Gene expression analysis in cells of the dentine-pulp complex in healthy and carious teeth. Arch Oral Biol 48: 273–283.
Miettinen, M., J. Lasota (2005) KIT (CD117): a review on expression in normal and neoplastic tissues, and mutations and their clinicopathologic correlation. Appl Immunohistochem Mol Morphol 13: 205–220.
Miletich, I., P.T. Sharpe (2004) Neural crest contribution to mammalian tooth formation. Birth Defects Res C Embryo Today 72: 200–212.
Miura, M., S. Gronthos, M. Zhao, B. Lu, L.W. Fisher, P.G. Robey, S. Shi (2003) SHED: stem cells from human exfoliated deciduous teeth. Proc Natl Acad Sci USA 100: 5807–5812.
Nakamura, S., T. Terashima, T. Yoshida, S. Iseki, Y. Takano, I. Ishikawa, T. Shinomura (2005) Identification of genes preferentially expressed in periodontal ligament: specific expression of a novel secreted protein, FDC-SP. Biochem Biophys Res Commun 338: 1197–1203.
Nosrat, I., A. Seiger, L. Olson, C.A. Nosrat (2002) Expression patterns of neurotrophic factor mRNAs in developing human teeth. Cell Tissue Res 310: 177–187.
Osmundsen, H., M.A. Landin, S.H. From, K.M. Kolltveit, S. Risnes (2007) Changes in gene-expression during development of the murine molar tooth germ. Arch Oral Biol 52: 803–813.
Pan, G.J., Z.Y. Chang, H.R. Scholer, D. Pei (2002) Stem cell pluripotency and transcription factor Oct4. Cell Res 12: 321–329.
Pierdomenico, L., L. Bonsi, M. Calvitti, D. Rondelli, M. Arpinati, G. Chirumbolo, E. Becchetti, C. Marchionni, F. Alviano, V. Fossati, N. Staffolani, M. Franchina, A. Grossi, G.P. Bagnara (2005) Multipotent mesenchymal stem cells with immunosuppressive activity can be easily isolated from dental pulp. Transplantation 80: 836–842.
Qiu, M., A. Bulfone, I. Ghattas, J.J. Meneses, L. Christensen, P.T. Sharpe, R. Presley, R.A. Pedersen, J.L. Rubenstein (1997) Role of the Dlx homeobox genes in proximodistal patterning of the branchial arches: mutations of Dlx-1, Dlx-2, and Dlx-1 and -2 alter morphogenesis of proximal skeletal and soft tissue structures derived from the first and second arches. Dev Biol 185: 165–184.
Seo, B.M., M. Miura, S. Gronthos, P.M. Bartold, S. Batouli, J. Brahim, M. Young, P.G. Robey, C.Y. Wang, S. Shi (2004) Investigation of multipotent postnatal stem cells from human periodontal ligament. Lancet 364: 149–155.
Shi, S., S. Gronthos (2003) Perivascular niche of postnatal mesenchymal stem cells in human bone marrow and dental pulp. J Bone Miner Res 18: 696–704.
Sonoyama, W., Y. Liu, D. Fang, T. Yamaza, B.M. Seo, C. Zhang, H. Liu, S. Gronthos, C.Y. Wang, S. Shi, S. Wang (2006) Mesenchymal stem cell-mediated functional tooth regeneration in swine. PLoS ONE 1: e79.
Ten Cate, A.R. (2003) Development of the Tooth and Its Supporting Tissues. St. Louis, Mosby.
Thesleff, I. (2003) Developmental biology and building a tooth. Quintessence Int 34: 613–620.
Tucker, A., P. Sharpe (2004) The cutting-edge of mammalian development; how the embryo makes teeth. Nat Rev Genet 5: 499–508.
Wise, G.E., S. Yao, P.R. Odgren, F. Pan (2005) CSF-1 regulation of osteoclastogenesis for tooth eruption. J Dent Res 84: 837–841.
Yamada, S., S. Murakami, R. Matoba, Y. Ozawa, T. Yokokoji, Y. Nakahira, K. Ikezawa, S. Takayama, K. Matsubara, H. Okada (2001) Expression profile of active genes in human periodontal ligament and isolation of PLAP-1, a novel SLRP family gene. Gene 275: 279–286.
Yamada, Y., A. Fujimoto, A. Ito, R. Yoshimi, M. Ueda (2006) Cluster analysis and gene expression profiles: a cDNA microarray system-based comparison between human dental pulp stem cells (hDPSCs) and human mesenchymal stem cells (hMSCs) for tissue engineering cell therapy. Biomaterials 27: 3766–3781.
Yates, A., I. Chambers (2005) The homeodomain protein Nanog and pluripotency in mouse embryonic stem cells. Biochem Soc Trans 33: 1518–1521.
Yu, H., D. Fang, S.M. Kumar, L. Li, T.K. Nguyen, G. Acs, M. Herlyn, X. Xu (2006) Isolation of a novel population of multipotent adult stem cells from human hair follicles. Am J Pathol 168: 1879–1888.
Zhang, Y.D., Z. Chen, Y.Q. Song, C. Liu, Y.P. Chen (2005) Making a tooth: growth factors, transcription factors, and stem cells. Cell Res 15: 301–316.
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