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Aguilar-Pedrayes I, Gardner JD, Organ CL. The coevolution of rostral keratin and tooth distribution in dinosaurs. Proc Biol Sci 2024; 291:20231713. [PMID: 38229513 DOI: 10.1098/rspb.2023.1713] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/31/2023] [Accepted: 12/11/2023] [Indexed: 01/18/2024] Open
Abstract
Teeth evolved early in vertebrate evolution, and their morphology reflects important specializations in diet and ecology among species. The toothless jaws (edentulism) in extant birds likely coevolved with beak keratin, which functionally replaced teeth. However, extinct dinosaurs lost teeth multiple times independently and exhibited great variation in toothrow distribution and rhamphotheca-like keratin structures. Here, we use rostral jawbone surface texture as a proxy for rostral keratin covering and phylogenetic comparative models to test for the influence of rostral keratin on toothrow distribution in Mesozoic dinosaurs. We find that the evolution of rostral keratin covering explains partial toothrow reduction but not jaw toothlessness. Toothrow reduction preceded the evolution of rostral keratin cover in theropods. Non-theropod dinosaurs evolved continuous toothrows despite evolving rostral keratin covers (e.g. some ornithischians and sauropodomorphs). We also show that rostral keratin covers did not significantly increase the evolutionary rate of tooth loss, which further delineates the antagonistic relationship between these structures. Our results suggest that the evolution of rostral keratin had a limited effect on suppressing tooth development. Independent changes in jaw development may have facilitated further tooth loss. Furthermore, the evolution of strong chemical digestion, a gizzard, and a dietary shift to omnivory or herbivory likely alleviated selective pressures for tooth development.
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Affiliation(s)
- Isaura Aguilar-Pedrayes
- Department of Earth Sciences, Montana State University, Bozeman, MT 59715, USA
- School of Earth Sciences, University of Bristol, Bristol BS8 1QU, UK
| | - Jacob D Gardner
- Department of Earth Sciences, Montana State University, Bozeman, MT 59715, USA
- School of Biological Sciences, University of Reading, Reading RG6 6AH, UK
| | - Chris L Organ
- Department of Earth Sciences, Montana State University, Bozeman, MT 59715, USA
- School of Biological Sciences, University of Reading, Reading RG6 6AH, UK
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2
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Kawasaki K, Sasagawa I, Mikami M, Nakatomi M, Ishiyama M. Ganoin and acrodin formation on scales and teeth in spotted gar: A vital role of enamelin in the unique process of enamel mineralization. JOURNAL OF EXPERIMENTAL ZOOLOGY. PART B, MOLECULAR AND DEVELOPMENTAL EVOLUTION 2023; 340:455-468. [PMID: 36464775 PMCID: PMC10239528 DOI: 10.1002/jez.b.23183] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/07/2022] [Revised: 11/12/2022] [Accepted: 11/15/2022] [Indexed: 12/12/2022]
Abstract
Gars and bichirs develop scales and teeth with ancient actinopterygian characteristics. Their scale surface and tooth collar are covered with enamel, also known as ganoin, whereas the tooth cap is equipped with an enamel-like tissue, acrodin. Here, we investigated the formation and mineralization of the ganoin and acrodin matrices in spotted gar, and the evolution of the scpp5, ameloblastin (ambn), and enamelin (enam) genes, which encode matrix proteins of ganoin. Results suggest that, in bichirs and gars, all these genes retain structural characteristics of their orthologs in stem actinopterygians, presumably reflecting the presence of ganoin on scales and teeth. During scale formation, Scpp5 and Enam were initially found in the incipient ganoin matrix and the underlying collagen matrix, whereas Ambn was detected mostly in a surface region of the well-developed ganoin matrix. Although collagen is the principal acrodin matrix protein, Scpp5 was detected within the matrix. Similarities in timings of mineralization and the secretion of Scpp5 suggest that acrodin evolved by the loss of the matrix secretory stage of ganoin formation: dentin formation is immediately followed by the maturation stage. The late onset of Ambn secretion during ganoin formation implies that Ambn is not essential for mineral ribbon formation, the hallmark of the enamel matrix. Furthermore, Scpp5 resembles amelogenin that is not important for the initial formation of mineral ribbons in mammals. It is thus likely that the evolution of ENAM was vital to the origin of the unique mineralization process of the enamel matrix.
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Affiliation(s)
- Kazuhiko Kawasaki
- Department of Anthropology, Pennsylvania State University, University Park, Pennsylvania, USA
| | - Ichiro Sasagawa
- Advanced Research Center, School of Life Dentistry at Niigata the Nippon Dental University, Niigata, Japan
| | - Masato Mikami
- Department of Microbiology, School of Life Dentistry at Niigata the Nippon Dental University, Niigata, Japan
| | - Mitsushiro Nakatomi
- Department of Human, Information and Life Sciences, School of Health Sciences, University of Occupational and Environmental Health, Kitakyushu, Japan
| | - Mikio Ishiyama
- Department of Histology, School of Life Dentistry at Niigata the Nippon Dental University, Niigata, Japan
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Ruspita I, Das P, Miyoshi K, Noma T, Snead ML, Bei M. Enam expression is regulated by Msx2. Dev Dyn 2023; 252:1292-1302. [PMID: 37191055 PMCID: PMC10592542 DOI: 10.1002/dvdy.598] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/03/2023] [Revised: 03/30/2023] [Accepted: 04/12/2023] [Indexed: 05/17/2023] Open
Abstract
BACKGROUND The precise formation of mineralized dental tissues such as enamel and/or dentin require tight transcriptional control of the secretion of matrix proteins. Here, we have investigated the transcriptional regulation of the second most prominent enamel matrix protein, enamelin, and its regulation through the major odontogenic transcription factor, MSX2. RESULTS Using in vitro and in vivo approaches, we identified that (a) Enam expression is reduced in the Msx2 mouse mutant pre-secretory and secretory ameloblasts, (b) Enam is an early response gene whose expression is under the control of Msx2, (c) Msx2 binds to Enam promoter in vitro, suggesting that enam is a direct target for Msx2 and that (d) Msx2 alone represses Enam gene expression. CONCLUSIONS Collectively, these results illustrate that Enam gene expression is controlled by Msx2 in a spatio-temporal manner. They also suggest that Msx2 may interact with other transcription factors to control spatial and temporal expression of Enam and hence amelogenesis and enamel biomineralization.
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Affiliation(s)
- Intan Ruspita
- Center for Regenerative and Developmental Biology, The Forsyth Institute, Cambridge, MA, USA
- Universitas Gadjah Mada, Yogyakarta, Indonesia
| | - Pragnya Das
- Center for Regenerative and Developmental Biology, The Forsyth Institute, Cambridge, MA, USA
- Cooper University Hospital, Camden, NJ, USA
| | - Keiko Miyoshi
- Department of Molecular Biology, Institute of Biomedical Sciences, Tokushima University, Tokushima, Japan
| | - Takafumi Noma
- Faculty of Human Life Studies, Hiroshima Jogakuin University, Hiroshima, Japan
| | - Malcolm L. Snead
- Center for Craniofacial Molecular Biology, Herman Ostrow School of Dentistry of USC, University of Southern California, LA, CA
| | - Marianna Bei
- Center for Engineering in Medicine and Surgery, Department of Surgery, Massachusetts General Hospital, Boston MA, USA
- Department of Surgery, Harvard Medical School, Boston MA, USA
- Shriners Hospital for Children, Boston, MA
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Naniwa K, Hirose K, Usami Y, Hata K, Araki R, Uzawa N, Komori T, Toyosawa S. Fam20C overexpression in odontoblasts regulates dentin formation and odontoblast differentiation. J Mol Histol 2023; 54:329-347. [PMID: 37357253 DOI: 10.1007/s10735-023-10123-y] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/14/2022] [Accepted: 04/27/2023] [Indexed: 06/27/2023]
Abstract
FAM20C phosphorylates secretory proteins at S-x-E/pS motifs, and previous studies of Fam20C-dificient mice revealed that FAM20C played essential roles in bone and tooth formation. Inactivation of FAM20C in mice led to hypophosphatemia that masks direct effect of FAM20C in these tissues, and consequently the direct role of FAM20C remains unknown. Our previous study reported that osteoblast/odontoblast-specific Fam20C transgenic (Fam20C-Tg) mice had normal serum phosphate levels and that osteoblastic FAM20C-mediated phosphorylation regulated bone formation and resorption. Here, we investigated the direct role of FAM20C in dentin using Fam20C-Tg mice. The tooth of Fam20C-Tg mice contained numerous highly phosphorylated proteins, including SIBLINGs, compared to that of wild-type mice. In Fam20C-Tg mice, coronal dentin volume decreased and mineral density unchanged at early age, while the volume unchanged and the mineral density elevated at maturity. In these mice, radicular dentin volume and mineral density decreased at all ages, and histologically, the radicular dentin had wider predentin and abnormal apical-side dentin with embedded cells and argyrophilic canaliculi. Immunohistochemical analyses revealed that abnormal apical-side dentin had bone and dentin matrix properties accompanied with osteoblast-lineage cells. Further, in Fam20C-Tg mice, DSPP content which is important for dentin formation, was reduced in dentin, especially radicular dentin, which might lead to defects mainly in radicular dentin. Renal subcapsular transplantations of tooth germ revealed that newly formed radicular dentin replicated apical abnormal dentin of Fam20C-Tg mice, corroborating that FAM20C overexpression indeed caused the abnormal dentin. Our findings indicate that odontoblastic FAM20C-mediated phosphorylation in the tooth regulates dentin formation and odontoblast differentiation.
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Affiliation(s)
- Kohei Naniwa
- Department of Oral and Maxillofacial Pathology, Osaka University Graduate School of Dentistry, 1-8 Yamadaoka, Suita, Osaka, 565-0871, Japan
- Department of Oral & Maxillofacial Oncology and Surgery, Osaka University Graduate School of Dentistry, 1-8 Yamadaoka, Suita, Osaka, 565-0871, Japan
| | - Katsutoshi Hirose
- Department of Oral and Maxillofacial Pathology, Osaka University Graduate School of Dentistry, 1-8 Yamadaoka, Suita, Osaka, 565-0871, Japan
| | - Yu Usami
- Department of Oral and Maxillofacial Pathology, Osaka University Graduate School of Dentistry, 1-8 Yamadaoka, Suita, Osaka, 565-0871, Japan
| | - Kenji Hata
- Department of Molecular and Cellular Biochemistry, Osaka University Graduate School of Dentistry, 1-8 Yamadaoka, Suita, Osaka, 565-0871, Japan
| | - Rikita Araki
- Bruker Japan K.K. BioSpin Division, Application Department, 3-9 Kanagawaku Moriyacho, Yokohama, Kanagawa, 221-0022, Japan
| | - Narikazu Uzawa
- Department of Oral & Maxillofacial Oncology and Surgery, Osaka University Graduate School of Dentistry, 1-8 Yamadaoka, Suita, Osaka, 565-0871, Japan
| | - Toshihisa Komori
- Department of Molecular Bone Biology, Nagasaki University Graduate School of Biomedical Sciences, 1-7-1 Sakamoto, Nagasaki, 852-8588, Japan
| | - Satoru Toyosawa
- Department of Oral and Maxillofacial Pathology, Osaka University Graduate School of Dentistry, 1-8 Yamadaoka, Suita, Osaka, 565-0871, Japan.
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Mu Y, Huang X, Liu R, Gai Y, Liang N, Yin D, Shan L, Xu S, Yang G. ACPT gene is inactivated in mammalian lineages that lack enamel or teeth. PeerJ 2021; 9:e10219. [PMID: 33552707 PMCID: PMC7831365 DOI: 10.7717/peerj.10219] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/06/2020] [Accepted: 09/29/2020] [Indexed: 12/31/2022] Open
Abstract
Loss of tooth or enamel is widespread in multiple mammal lineages. Although several studies have been reported, the evolutionary mechanisms of tooth/enamel loss are still unclear. Most previous studies have found that some tooth-related genes have been inactivated in toothless and/or enamel-less mammals, such as ENAM, ODAM, C4orf26, AMBN, AMTN, DSPP, etc. Here, we conducted evolutionary analyses on ACPT playing a key role in amelogenesis, to interrogate the mechanisms. We obtained the ACPT sequences from 116 species, including edentulous and enamel-less mammals. The results shows that variant ORF-disrupting mutations were detected in ACPT coding region among nine edentulous baleen whales and three enamel-less taxa (pygmy sperm whale, aardvark, nine-banded armadillo). Furtherly, selective pressure uncovered that the selective constraints have been relaxed among all toothless and enamel-less lineages. Moreover, our results support the hypothesis that mineralized teeth were lost or degenerated in the common ancestor of crown Mysticeti through two shared single-base sites deletion in exon 4 and 5 of ACPT among all living baleen whales. DN/dS values on transitional branches were used to estimate ACPT inactivation records. In the case of aardvark, inactivation of ACPT was estimated at ~23.60–28.32 Ma, which is earlier than oldest aardvark fossil record (Orycteropus minutus, ~19 Ma), suggesting that ACPT inactivation may result in degeneration or loss of enamel. Conversely, the inactivation time of ACPT estimated in armadillo (~10.18–11.30 Ma) is later than oldest fossil record, suggesting that inactivation of ACPT may result from degeneration or loss of enamel in these mammals. Our findings suggested that different mechanisms of degeneration of tooth/enamel might exist among toothless and enamel-less lineages during evolution. Our study further considered that ACPT is a novel gene for studying tooth evolution.
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Affiliation(s)
- Yuan Mu
- Jiangsu Key Laboratory for Biodiversity and Biotechnology, College of Life Sciences, Nanjing Normal University, Nanjing, Jiangsu, China
| | - Xin Huang
- Jiangsu Key Laboratory for Biodiversity and Biotechnology, College of Life Sciences, Nanjing Normal University, Nanjing, Jiangsu, China
| | - Rui Liu
- Jiangsu Key Laboratory for Biodiversity and Biotechnology, College of Life Sciences, Nanjing Normal University, Nanjing, Jiangsu, China
| | - Yulin Gai
- Jiangsu Key Laboratory for Biodiversity and Biotechnology, College of Life Sciences, Nanjing Normal University, Nanjing, Jiangsu, China
| | - Na Liang
- Jiangsu Key Laboratory for Biodiversity and Biotechnology, College of Life Sciences, Nanjing Normal University, Nanjing, Jiangsu, China
| | - Daiqing Yin
- Jiangsu Key Laboratory for Biodiversity and Biotechnology, College of Life Sciences, Nanjing Normal University, Nanjing, Jiangsu, China
| | - Lei Shan
- Jiangsu Key Laboratory for Biodiversity and Biotechnology, College of Life Sciences, Nanjing Normal University, Nanjing, Jiangsu, China
| | - Shixia Xu
- Jiangsu Key Laboratory for Biodiversity and Biotechnology, College of Life Sciences, Nanjing Normal University, Nanjing, Jiangsu, China
| | - Guang Yang
- Jiangsu Key Laboratory for Biodiversity and Biotechnology, College of Life Sciences, Nanjing Normal University, Nanjing, Jiangsu, China
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Alazem O, Abramyan J. Reptile enamel matrix proteins: Selection, divergence, and functional constraint. JOURNAL OF EXPERIMENTAL ZOOLOGY PART B-MOLECULAR AND DEVELOPMENTAL EVOLUTION 2019; 332:136-148. [PMID: 31045323 DOI: 10.1002/jez.b.22857] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/30/2018] [Revised: 02/24/2019] [Accepted: 04/01/2019] [Indexed: 12/14/2022]
Abstract
The three major enamel matrix proteins (EMPs): amelogenin (AMEL), ameloblastin (AMBN), and enamelin (ENAM), are intrinsically linked to tooth development in tetrapods. However, reptiles and mammals exhibit significant differences in dental patterning and development, potentially affecting how EMPs evolve in each group. In most reptiles, teeth are replaced continuously throughout life, while mammals have reduced replacement to only one or two generations. Reptiles also form structurally simple, aprismatic enamel while mammalian enamel is composed of highly organized hydroxyapatite prisms. These differences, combined with reported low sequence homology in reptiles, led us to predict that reptiles may experience lower selection pressure on their EMPs as compared with mammals. However, we found that like mammals, reptile EMPs are under moderate purifying selection, with some differences evident between AMEL, AMBN, and ENAM. We also demonstrate that sequence homology in reptile EMPs is closely associated with divergence times, with more recently diverged lineages exhibiting high homology, along with strong phylogenetic signal. Lastly, despite sequence divergence, none of the reptile species in our study exhibited mutations consistent with diseases that cause degeneration of enamel (e.g. amelogenesis imperfecta). Despite short tooth retention time and simplicity in enamel structure, reptile EMPs still exhibit purifying selection required to form durable enamel.
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Affiliation(s)
- Omar Alazem
- Department of Natural Sciences, University of Michigan-Dearborn, Dearborn, Michigan
| | - John Abramyan
- Department of Natural Sciences, University of Michigan-Dearborn, Dearborn, Michigan
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7
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Springer MS, Emerling CA, Gatesy J, Randall J, Collin MA, Hecker N, Hiller M, Delsuc F. Odontogenic ameloblast-associated (ODAM) is inactivated in toothless/enamelless placental mammals and toothed whales. BMC Evol Biol 2019; 19:31. [PMID: 30674270 PMCID: PMC6343362 DOI: 10.1186/s12862-019-1359-6] [Citation(s) in RCA: 14] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/18/2018] [Accepted: 01/11/2019] [Indexed: 11/10/2022] Open
Abstract
Background The gene for odontogenic ameloblast-associated (ODAM) is a member of the secretory calcium-binding phosphoprotein gene family. ODAM is primarily expressed in dental tissues including the enamel organ and the junctional epithelium, and may also have pleiotropic functions that are unrelated to teeth. Here, we leverage the power of natural selection to test competing hypotheses that ODAM is tooth-specific versus pleiotropic. Specifically, we compiled and screened complete protein-coding sequences, plus sequences for flanking intronic regions, for ODAM in 165 placental mammals to determine if this gene contains inactivating mutations in lineages that either lack teeth (baleen whales, pangolins, anteaters) or lack enamel on their teeth (aardvarks, sloths, armadillos), as would be expected if the only essential functions of ODAM are related to tooth development and the adhesion of the gingival junctional epithelium to the enamel tooth surface. Results We discovered inactivating mutations in all species of placental mammals that either lack teeth or lack enamel on their teeth. A surprising result is that ODAM is also inactivated in a few additional lineages including all toothed whales that were examined. We hypothesize that ODAM inactivation is related to the simplified outer enamel surface of toothed whales. An alternate hypothesis is that ODAM inactivation in toothed whales may be related to altered antimicrobial functions of the junctional epithelium in aquatic habitats. Selection analyses on ODAM sequences revealed that the composite dN/dS value for pseudogenic branches is close to 1.0 as expected for a neutrally evolving pseudogene. DN/dS values on transitional branches were used to estimate ODAM inactivation times. In the case of pangolins, ODAM was inactivated ~ 65 million years ago, which is older than the oldest pangolin fossil (Eomanis, 47 Ma) and suggests an even more ancient loss or simplification of teeth in this lineage. Conclusion Our results validate the hypothesis that the only essential functions of ODAM that are maintained by natural selection are related to tooth development and/or the maintenance of a healthy junctional epithelium that attaches to the enamel surface of teeth. Electronic supplementary material The online version of this article (10.1186/s12862-019-1359-6) contains supplementary material, which is available to authorized users.
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Affiliation(s)
- Mark S Springer
- Department of Evolution, Ecology, and Organismal Biology, University of California, Riverside, CA, 92521, USA.
| | - Christopher A Emerling
- Institut des Sciences de l'Évolution de Montpellier (ISEM), CNRS, IRD, EPHE, Université de Montpellier, Montpellier, France.,Department of Biology, Whittier College, Whittier, CA, 90602, USA
| | - John Gatesy
- Division of Vertebrate Zoology and Sackler Institute for Comparative Genomics, American Museum of Natural History, New York, NY, 10024, USA
| | - Jason Randall
- Department of Evolution, Ecology, and Organismal Biology, University of California, Riverside, CA, 92521, USA
| | - Matthew A Collin
- Department of Evolution, Ecology, and Organismal Biology, University of California, Riverside, CA, 92521, USA
| | - Nikolai Hecker
- Max Planck Institute of Molecular Cell Biology and Genetics, Dresden, Germany.,Max Planck Institute for the Physics of Complex Systems, Dresden, Germany.,Center for Systems Biology Dresden, Dresden, Germany
| | - Michael Hiller
- Max Planck Institute of Molecular Cell Biology and Genetics, Dresden, Germany.,Max Planck Institute for the Physics of Complex Systems, Dresden, Germany.,Center for Systems Biology Dresden, Dresden, Germany
| | - Frédéric Delsuc
- Institut des Sciences de l'Évolution de Montpellier (ISEM), CNRS, IRD, EPHE, Université de Montpellier, Montpellier, France
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8
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Bony pseudoteeth of extinct pelagic birds (Aves, Odontopterygiformes) formed through a response of bone cells to tooth-specific epithelial signals under unique conditions. Sci Rep 2018; 8:12952. [PMID: 30154516 PMCID: PMC6113277 DOI: 10.1038/s41598-018-31022-3] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/04/2018] [Accepted: 07/26/2018] [Indexed: 02/06/2023] Open
Abstract
Modern birds (crown group birds, called Neornithes) are toothless; however, the extinct neornithine Odontopterygiformes possessed bone excrescences (pseudoteeth) which resembled teeth, distributed sequentially by size along jaws. The origin of pseudoteeth is enigmatic, but based on recent evidence, including microanatomical and histological analyses, we propose that conserved odontogenetic pathways most probably regulated the development of pseudodentition. The delayed pseudoteeth growth and epithelium keratinization allowed for the existence of a temporal window during which competent osteoblasts could respond to oral epithelial signaling, in place of the no longer present odontoblasts; thus, bony pseudoteeth developed instead of true teeth. Dynamic morphogenetic fields can explain the particular, sequential size distribution of pseudoteeth along the jaws of these birds. Hence, this appears as a new kind of deep homology, by which ancient odontogenetic developmental processes would have controlled the evolution of pseudodentition, structurally different from a true dentition, but morphologically and functionally similar.
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9
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Smith KT, Bhullar BAS, Köhler G, Habersetzer J. The Only Known Jawed Vertebrate with Four Eyes and the Bauplan of the Pineal Complex. Curr Biol 2018; 28:1101-1107.e2. [PMID: 29614279 DOI: 10.1016/j.cub.2018.02.021] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/20/2017] [Revised: 12/22/2017] [Accepted: 02/13/2018] [Indexed: 11/29/2022]
Abstract
The pineal and parapineal organs are dorsal outpocketings of the vertebrate diencephalon that play key roles in orientation and in circadian and annual cycles. Lampreys are four eyed in that both the pineal and parapineal form eyelike photosensory structures, but the pineal is the dominant or sole median photosensory structure in most lower vertebrate clades. The pineal complex has been thought to evolve in a single direction by losing photosensory and augmenting secretory function in the transitions from three-eyed lower vertebrates to two-eyed mammals and archosaurs [1-3]. Yet the widely accepted elaboration of the parapineal instead of the pineal as the primary median photosensory organ [4] in Lepidosauria (lizards, snakes, and tuataras) hints at a more complex evolutionary history. Here we present evidence that a fourth eye re-evolved from the pineal organ at least once within vertebrates, specifically in an extinct monitor lizard, Saniwa ensidens, in which pineal and parapineal eyes were present simultaneously. The tandem midline location of these structures confirms in a striking fashion the proposed homology of the parietal eye with the parapineal organ and refutes the classical model of pineal bilaterality. It furthermore raises questions about the evolution and functional interpretation of the median photosensory organ in other tetrapod clades.
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Affiliation(s)
- Krister T Smith
- Department of Messel Research and Mammalogy, Senckenberg Research Institute, Senckenberganlage 25, 60325 Frankfurt am Main, Germany; Department of Geology and Geophysics and Peabody Museum of Natural History, Yale University, 210 Whitney Avenue, New Haven, CT 06511, USA.
| | - Bhart-Anjan S Bhullar
- Department of Geology and Geophysics and Peabody Museum of Natural History, Yale University, 210 Whitney Avenue, New Haven, CT 06511, USA
| | - Gunther Köhler
- Section of Herpetology, Senckenberg Research Institute, Senckenberganlage 25, 60325 Frankfurt am Main, Germany
| | - Jörg Habersetzer
- Department of Messel Research and Mammalogy, Senckenberg Research Institute, Senckenberganlage 25, 60325 Frankfurt am Main, Germany
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10
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Emerling CA, Widjaja AD, Nguyen NN, Springer MS. Their loss is our gain: regressive evolution in vertebrates provides genomic models for uncovering human disease loci. J Med Genet 2017; 54:787-794. [PMID: 28814606 DOI: 10.1136/jmedgenet-2017-104837] [Citation(s) in RCA: 25] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/29/2017] [Revised: 07/07/2017] [Accepted: 07/10/2017] [Indexed: 12/20/2022]
Abstract
Throughout Earth's history, evolution's numerous natural 'experiments' have resulted in a diverse range of phenotypes. Though de novo phenotypes receive widespread attention, degeneration of traits inherited from an ancestor is a very common, yet frequently neglected, evolutionary path. The latter phenomenon, known as regressive evolution, often results in vertebrates with phenotypes that mimic inherited disease states in humans. Regressive evolution of anatomical and/or physiological traits is typically accompanied by inactivating mutations underlying these traits, which frequently occur at loci identical to those implicated in human diseases. Here we discuss the potential utility of examining the genomes of vertebrates that have experienced regressive evolution to inform human medical genetics. This approach is low cost and high throughput, giving it the potential to rapidly improve knowledge of disease genetics. We discuss two well-described examples, rod monochromacy (congenital achromatopsia) and amelogenesis imperfecta, to demonstrate the utility of this approach, and then suggest methods to equip non-experts with the ability to corroborate candidate genes and uncover new disease loci.
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Affiliation(s)
- Christopher A Emerling
- Museum of Vertebrate Zoology, University of California, Berkeley, California, USA
- Department of Biology, University of California, Riverside, California, USA
| | - Andrew D Widjaja
- Department of Biochemistry, University of California, Riverside, California, USA
- Department of Nutritional Sciences and Toxicology, University of California, Berkeley, California, USA
| | - Nancy N Nguyen
- Department of Bioengineering, University of California, Riverside, California, USA
- Department of Bioengineering, University of California, Los Angeles, California, USA
| | - Mark S Springer
- Department of Biology, University of California, Riverside, California, USA
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11
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Yan WJ, Ma P, Tian Y, Wang JY, Qin CL, Feng JQ, Wang XF. The importance of a potential phosphorylation site in enamelin on enamel formation. Int J Oral Sci 2017; 9:e4. [PMID: 29593332 PMCID: PMC5775333 DOI: 10.1038/ijos.2017.41] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 08/01/2017] [Indexed: 01/31/2023] Open
Abstract
Enamelin (ENAM) has three putative phosphoserines (pSers) phosphorylated by a Golgi-associated secretory pathway kinase (FAM20C) based on their distinctive Ser-x-Glu (S-x-E) motifs. Fam20C-knockout mice show severe enamel defects similar to those in the Enam-knockout mice, implying an important role of the pSers in ENAM. To determine the role of pSer55 in ENAM, we characterized ENAMRgsc514 mice, in which Ser55 cannot be phosphorylated by FAM20C due to an E57>G57 mutation in the S-x-E motif. The enamel microstructure of 4-week-old mice was examined by scanning electron microscopy. The teeth of 6-day-old mice were characterized by histology and immunohistochemistry. The protein lysates of the first lower molars of 4-day-old mice were analyzed by Western immunoblotting using antibodies against ENAM, ameloblastin and amelogenin. ENAMRgsc514 heterozygotes showed a disorganized enamel microstructure, while the homozygotes had no enamel on the dentin surface. The N-terminal fragments of ENAM in the heterozygotes were detained in the ameloblasts and localized in the mineralization front of enamel matrix, while those in the WT mice were secreted out of ameloblasts and distributed evenly in the outer 1/2 of enamel matrix. Surprisingly, the ~15 kDa C-terminal fragments of ameloblastin were not detected in the molar lysates of the homozygotes. These results suggest that the phosphorylation of Ser55 may be an essential posttranslational modification of ENAM and is required for the interaction with other enamel matrix molecules such as ameloblastin in mediating the structural organization of enamel matrix and protein-mineral interactions during enamel formation.International Journal of Oral Science (2017) 9;e4; doi:10.1038/ijos.2017.41; published online 29 November 2017.
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Affiliation(s)
- Wen-Juan Yan
- Department of Biomedical Sciences and Center for Craniofacial Research and Diagnosis, Texas A&M University College of Dentistry, Dallas, USA.,Department of Endodontics, Nanfan Hospital, Southern Medical University, Guangzhou, China
| | - Pan Ma
- Department of Biomedical Sciences and Center for Craniofacial Research and Diagnosis, Texas A&M University College of Dentistry, Dallas, USA
| | - Ye Tian
- Department of Biomedical Sciences and Center for Craniofacial Research and Diagnosis, Texas A&M University College of Dentistry, Dallas, USA
| | - Jing-Ya Wang
- Department of Biomedical Sciences and Center for Craniofacial Research and Diagnosis, Texas A&M University College of Dentistry, Dallas, USA
| | - Chun-Lin Qin
- Department of Biomedical Sciences and Center for Craniofacial Research and Diagnosis, Texas A&M University College of Dentistry, Dallas, USA
| | - Jian Q Feng
- Department of Biomedical Sciences and Center for Craniofacial Research and Diagnosis, Texas A&M University College of Dentistry, Dallas, USA
| | - Xiao-Fang Wang
- Department of Biomedical Sciences and Center for Craniofacial Research and Diagnosis, Texas A&M University College of Dentistry, Dallas, USA
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12
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Dumont M, Tafforeau P, Bertin T, Bhullar BA, Field D, Schulp A, Strilisky B, Thivichon-Prince B, Viriot L, Louchart A. Synchrotron imaging of dentition provides insights into the biology of Hesperornis and Ichthyornis, the "last" toothed birds. BMC Evol Biol 2016; 16:178. [PMID: 27659919 PMCID: PMC5034473 DOI: 10.1186/s12862-016-0753-6] [Citation(s) in RCA: 39] [Impact Index Per Article: 4.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/26/2016] [Accepted: 08/23/2016] [Indexed: 01/28/2023] Open
Abstract
Background The dentitions of extinct organisms can provide pivotal information regarding their phylogenetic position, as well as paleobiology, diet, development, and growth. Extant birds are edentulous (toothless), but their closest relatives among stem birds, the Cretaceous Hesperornithiformes and Ichthyornithiformes, retained teeth. Despite their significant phylogenetic position immediately outside the avian crown group, the dentitions of these taxa have never been studied in detail. To obtain new insight into the biology of these ‘last’ toothed birds, we use cutting-edge visualisation techniques to describe their dentitions at unprecedented levels of detail, in particular propagation phase contrast x-ray synchrotron microtomography at high-resolution. Results Among other characteristics of tooth shape, growth, attachment, implantation, replacement, and dental tissue microstructures, revealed by these analyses, we find that tooth morphology and ornamentation differ greatly between the Hesperornithiformes and Ichthyornithiformes. We also highlight the first Old World, and youngest record of the major Mesozoic clade Ichthyornithiformes. Both taxa exhibit extremely thin and simple enamel. The extension rate of Hesperornis tooth dentine appears relatively high compared to non-avian dinosaurs. Root attachment is found for the first time to be fully thecodont via gomphosis in both taxa, but in Hesperornis secondary evolution led to teeth implantation in a groove, at least locally without a periodontal ligament. Dental replacement is shown to be lingual via a resorption pit in the root, in both taxa. Conclusions Our results allow comparison with other archosaurs and also mammals, with implications regarding dental character evolution across amniotes. Some dental features of the ‘last’ toothed birds can be interpreted as functional adaptations related to diet and mode of predation, while others appear to be products of their peculiar phylogenetic heritage. The autapomorphic Hesperornis groove might have favoured firmer root attachment. These observations highlight complexity in the evolutionary history of tooth reduction in the avian lineage and also clarify alleged avian dental characteristics in the frame of a long-standing debate on bird origins. Finally, new hypotheses emerge that will possibly be tested by further analyses of avian teeth, for instance regarding dental replacement rates, or simplification and thinning of enamel throughout the course of early avian evolution. Electronic supplementary material The online version of this article (doi:10.1186/s12862-016-0753-6) contains supplementary material, which is available to authorized users.
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Affiliation(s)
- Maïtena Dumont
- Centre National de la Recherche Scientifique, Unité Mixte de Recherche 5242, Institut de Génomique Fonctionnelle de Lyon, Equipe évo-dévo de la denture chez les vertébrés, Ecole Normale Supérieure de Lyon, Université Lyon 1, 46 Allée d'Italie, 69364, Lyon cedex 7, France.,UMR CNRS/MNHN 7179, "Mécanismes adaptatifs: des organismes aux communautés", 57 rue Cuvier CP55, 75005, Paris, France
| | - Paul Tafforeau
- ESRF-The European Synchrotron, 71, avenue des Martyrs, CS 40220, F-38043, Grenoble Cédex 9, France
| | - Thomas Bertin
- Centre National de la Recherche Scientifique, Unité Mixte de Recherche 5242, Institut de Génomique Fonctionnelle de Lyon, Equipe évo-dévo de la denture chez les vertébrés, Ecole Normale Supérieure de Lyon, Université Lyon 1, 46 Allée d'Italie, 69364, Lyon cedex 7, France
| | - Bhart-Anjan Bhullar
- Department of Geology and Geophysics and Peabody Museum of Natural History, Yale University, New Haven, 06520, CT, USA
| | - Daniel Field
- Department of Geology and Geophysics and Peabody Museum of Natural History, Yale University, New Haven, 06520, CT, USA
| | - Anne Schulp
- Natuurhistorisch Museum Maastricht, De Bosquetplein 6-7, NL-6211 KJ, Maastricht, The Netherlands.,Present Address: Naturalis Biodiversity Center, Darwinweg 2, 2333CR, Leiden, The Netherlands
| | - Brandon Strilisky
- Royal Tyrrell Museum of Palaeontology, P.O. Box 7500, Drumheller, T0J 0Y0, AB, Canada
| | - Béatrice Thivichon-Prince
- Centre National de la Recherche Scientifique, Unité Mixte de Recherche 5242, Institut de Génomique Fonctionnelle de Lyon, Equipe évo-dévo de la denture chez les vertébrés, Ecole Normale Supérieure de Lyon, Université Lyon 1, 46 Allée d'Italie, 69364, Lyon cedex 7, France
| | - Laurent Viriot
- Centre National de la Recherche Scientifique, Unité Mixte de Recherche 5242, Institut de Génomique Fonctionnelle de Lyon, Equipe évo-dévo de la denture chez les vertébrés, Ecole Normale Supérieure de Lyon, Université Lyon 1, 46 Allée d'Italie, 69364, Lyon cedex 7, France
| | - Antoine Louchart
- Centre National de la Recherche Scientifique, Unité Mixte de Recherche 5242, Institut de Génomique Fonctionnelle de Lyon, Equipe évo-dévo de la denture chez les vertébrés, Ecole Normale Supérieure de Lyon, Université Lyon 1, 46 Allée d'Italie, 69364, Lyon cedex 7, France. .,Centre National de la Recherche Scientifique, Unité Mixte de Recherche 5553, LECA, Equipe Paléo-Génomique, and Palgene (CNRS/ENS de Lyon), Ecole Normale Supérieure de Lyon, Université de Lyon, 46 Allée d'Italie, 69364, Lyon cedex 7, France.
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13
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Ma P, Yan W, Tian Y, He J, Brookes SJ, Wang X. The Importance of Serine Phosphorylation of Ameloblastin on Enamel Formation. J Dent Res 2016; 95:1408-1414. [PMID: 27470066 DOI: 10.1177/0022034516661513] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/08/2023] Open
Abstract
FAM20C is a newly identified kinase on the secretory pathway responsible for the phosphorylation of serine residues in the Ser-x-Glu/pSer motifs in several enamel matrix proteins. Fam20C-knockout mice showed severe enamel defects very similar to those in the ameloblastin ( Ambn)-knockout mice, implying that phosphoserines may have a critical role in AMBN function. To test this hypothesis, we generated amelogenin ( Amel) promoter-driven Ambn-transgenic mice, in which Ser48, Ser226, and Ser227 were replaced by aspartic acid (designated as D-Tg) or alanines (designated as A-Tg). The negative charge of aspartic acid is believed to be able to mimic the phosphorylation state of serine, while alanine is a commonly used residue to substitute serine due to their similar structure. Using Western immunoblotting and quantitative polymerase chain reaction, the authors identified transgenic lines expressing transgenes somewhat higher (Tg+) or much higher (Tg++) than endogenous Ambn. The lower incisors collected from 7-d-old and 7-wk-old mice were analyzed by histology, scanning electron microscopy, immunohistochemistry, and Western immunoblotting to examine the morphology and microstructure changes in enamel, as well as the expression pattern of enamel matrix proteins. The A-Tg+ and A-Tg++ mice displayed severe enamel defects in spite of the expression level of transgenes, while the D-Tg+ and D-Tg++ mice showed minor to mild enamel defects, indicating that the D-Tg transgenes disturbed enamel formation less than the A-Tg transgenes did. Our results suggest that the phosphorylation state of serines is likely an essential component for the integrity of AMBN function.
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Affiliation(s)
- P Ma
- 1 Department of Oral Implantology, Beijing Stomatological Hospital, Capital Medical University, Beijing, China.,2 Department of Biomedical Sciences and Center for Craniofacial Research and Diagnosis, Texas A&M University Baylor College of Dentistry, Dallas, TX, USA
| | - W Yan
- 2 Department of Biomedical Sciences and Center for Craniofacial Research and Diagnosis, Texas A&M University Baylor College of Dentistry, Dallas, TX, USA
| | - Y Tian
- 2 Department of Biomedical Sciences and Center for Craniofacial Research and Diagnosis, Texas A&M University Baylor College of Dentistry, Dallas, TX, USA
| | - J He
- 2 Department of Biomedical Sciences and Center for Craniofacial Research and Diagnosis, Texas A&M University Baylor College of Dentistry, Dallas, TX, USA
| | - S J Brookes
- 3 Department of Oral Biology, University of Leeds, St. James's University Hospital, Leeds, UK
| | - X Wang
- 2 Department of Biomedical Sciences and Center for Craniofacial Research and Diagnosis, Texas A&M University Baylor College of Dentistry, Dallas, TX, USA
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Gasse B, Sire JY. Comparative expression of the four enamel matrix protein genes, amelogenin, ameloblastin, enamelin and amelotin during amelogenesis in the lizard Anolis carolinensis. EvoDevo 2015; 6:29. [PMID: 26421144 PMCID: PMC4587831 DOI: 10.1186/s13227-015-0024-4] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/05/2015] [Accepted: 09/15/2015] [Indexed: 12/23/2022] Open
Abstract
Background In a recent study, we have demonstrated that amelotin (AMTN) gene structure and its expression during amelogenesis have changed during tetrapod evolution. Indeed, this gene is expressed throughout enamel matrix deposition and maturation in non-mammalian tetrapods, while in mammals its expression is restricted to the transition and maturation stages of amelogenesis. Previous studies of amelogenin (AMEL) gene expression in a lizard and a salamander have shown similar expression pattern to that in mammals, but to our knowledge there are no data regarding ameloblastin (AMBN) and enamelin (ENAM) expression in non-mammalian tetrapods. The present study aims to look at, and compare, the structure and expression of four enamel matrix protein genes, AMEL, AMBN, ENAM and AMTN during amelogenesis in the lizard Anolis carolinensis. Results We provide the full-length cDNA sequence of A. carolinensisAMEL and AMBN, and show for the first time the expression of ENAM and AMBN in a non-mammalian species. During amelogenesis in A. carolinensis, AMEL, AMBN and ENAM expression in ameloblasts is similar to that described in mammals. It is noteworthy that AMEL and AMBN expression is also found in odontoblasts. Conclusions Our findings indicate that AMTN is the only enamel matrix protein gene that is differentially expressed in ameloblasts between mammals and sauropsids. Changes in AMTN structure and expression could be the key to explain the structural differences between mammalian and reptilian enamel, i.e. prismatic versus non-prismatic.
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Affiliation(s)
- Barbara Gasse
- UMR7138, Institut de Biologie Paris-Seine (IBPS), UPMC Univ Paris 06, Sorbonne Universités, 75005 Paris, France
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15
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Evolutionary analysis of selective constraints identifies ameloblastin (AMBN) as a potential candidate for amelogenesis imperfecta. BMC Evol Biol 2015. [PMID: 26223266 PMCID: PMC4518657 DOI: 10.1186/s12862-015-0431-0] [Citation(s) in RCA: 22] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022] Open
Abstract
Background Ameloblastin (AMBN) is a phosphorylated, proline/glutamine-rich protein secreted during enamel formation. Previous studies have revealed that this enamel matrix protein was present early in vertebrate evolution and certainly plays important roles during enamel formation although its precise functions remain unclear. We performed evolutionary analyses of AMBN in order to (i) identify residues and motifs important for the protein function, (ii) predict mutations responsible for genetic diseases, and (iii) understand its molecular evolution in mammals. Results In silico searches retrieved 56 complete sequences in public databases that were aligned and analyzed computationally. We showed that AMBN is globally evolving under moderate purifying selection in mammals and contains a strong phylogenetic signal. In addition, our analyses revealed codons evolving under significant positive selection. Evidence for positive selection acting on AMBN was observed in catarrhine primates and the aye-aye. We also found that (i) an additional translation initiation site was recruited in the ancestral placental AMBN, (ii) a short exon was duplicated several times in various species including catarrhine primates, and (iii) several polyadenylation sites are present. Conclusions AMBN possesses many positions, which have been subjected to strong selective pressure for 200 million years. These positions correspond to several cleavage sites and hydroxylated, O-glycosylated, and phosphorylated residues. We predict that these conserved positions would be potentially responsible for enamel disorder if substituted. Some motifs that were previously identified as potentially important functionally were confirmed, and we found two, highly conserved, new motifs, the function of which should be tested in the near future. This study illustrates the power of evolutionary analyses for characterizing the functional constraints acting on proteins with yet uncharacterized structure. Electronic supplementary material The online version of this article (doi:10.1186/s12862-015-0431-0) contains supplementary material, which is available to authorized users.
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16
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Gasse B, Liu X, Corre E, Sire JY. Amelotin Gene Structure and Expression during Enamel Formation in the Opossum Monodelphis domestica. PLoS One 2015; 10:e0133314. [PMID: 26186457 PMCID: PMC4506066 DOI: 10.1371/journal.pone.0133314] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/16/2015] [Accepted: 06/24/2015] [Indexed: 11/23/2022] Open
Abstract
Amelotin (AMTN) is an ameloblast-secreted protein that belongs to the secretory calcium-binding phosphoprotein family, which also includes the enamel matrix proteins amelogenin, ameloblastin and enamelin. Although AMTN is supposed to play an important role in enamel formation, data were long limited to the rodents, in which it is expressed during the maturation stage. Recent comparative studies in sauropsids and amphibians revealed that (i) AMTN was expressed earlier, i.e. as soon as ameloblasts are depositing the enamel matrix, and (ii) AMTN structure was different, a change which mostly resulted from an intraexonic splicing in the large exon 8 of an ancestral mammal. The present study was performed to know whether the differences in AMTN structure and expression in rodents compared to non-mammalian tetrapods dated back to an early ancestral mammal or were acquired later in mammalian evolution. We sequenced, assembled and screened the jaw transcriptome of a neonate opossum Monodelphis domestica, a marsupial. We found two AMTN transcripts. Variant 1, representing 70.8% of AMTN transcripts, displayed the structure known in rodents, whereas variant 2 (29.2%) exhibited the nonmammalian tetrapod structure. Then, we studied AMTN expression during amelogenesis in a neonate specimen. We obtained similar data as those reported in rodents. These findings indicate that more than 180 million years ago, before the divergence of marsupials and placentals, changes occurred in AMTN function and structure. The spatiotemporal expression was delayed to the maturation stage of amelogenesis and the intraexonic splicing gave rise to isoform 1, encoded by variant 1 and lacking the RGD motif. The ancestral isoform 2, housing the RGD, was initially conserved, as demonstrated here in a marsupial, then secondarily lost in the placental lineages. These findings bring new elements towards our understanding of the non-prismatic to prismatic enamel transition that occurred at the onset of mammals.
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Affiliation(s)
- Barbara Gasse
- Sorbonne Universités, UPMC Univ Paris 06, Institut de Biologie Paris-Seine (IBPS), UMR7138, 75005 Paris, France
- CNRS, IBPS, UMR7138, 75005 Paris, France
| | - Xi Liu
- Sorbonne Universités, UPMC Univ Paris 06, Institut de Biologie Paris-Seine (IBPS), UMR7138, 75005 Paris, France
- CNRS, IBPS, UMR7138, 75005 Paris, France
- Sorbonne Universités, UPMC Univ Paris 06, Station Biologique de Roscoff, Plateforme ABiMS (Analyses and Bioinformatics for Marine Science), 29680 Roscoff, France
| | - Erwan Corre
- Sorbonne Universités, UPMC Univ Paris 06, Station Biologique de Roscoff, Plateforme ABiMS (Analyses and Bioinformatics for Marine Science), 29680 Roscoff, France
| | - Jean-Yves Sire
- Sorbonne Universités, UPMC Univ Paris 06, Institut de Biologie Paris-Seine (IBPS), UMR7138, 75005 Paris, France
- CNRS, IBPS, UMR7138, 75005 Paris, France
- * E-mail:
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17
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Kawasaki K, Amemiya CT. SCPP genes in the coelacanth: tissue mineralization genes shared by sarcopterygians. JOURNAL OF EXPERIMENTAL ZOOLOGY PART B-MOLECULAR AND DEVELOPMENTAL EVOLUTION 2015; 322:390-402. [PMID: 25243252 DOI: 10.1002/jez.b.22546] [Citation(s) in RCA: 34] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/11/2022]
Abstract
The coelacanth is the basal-most extant sarcopterygian that has teeth and tooth-like structures, comprising bone, dentin, and enamel or enameloid. Formation of these tissues involves many members of the secretory calcium-binding protein (SCPP) family. In tetrapods, acidic-residue-rich SCPPs are used in mineralization of bone and dentin, whereas Pro/Gln-rich SCPPs participate in enamel formation. Teleosts also employ many SCPPs for tissue mineralization. Nevertheless, the repertoire of SCPPs is largely different in teleosts and tetrapods; hence, filling this gap would be critical to elucidate early evolution of mineralized tissues in osteichthyans. In the present study, we searched for SCPP genes in the coelacanth genome and identified 11, of which two have clear orthologs in both tetrapods and teleosts, seven only in tetrapods, and two in neither of them. Given the divergence times of these vertebrate lineages, our discovery of this many SCPP genes shared between the coelacanth and tetrapods, but not with teleosts, suggests a complicated evolutionary scheme of SCPP genes in early osteichthyans. Our investigation also revealed both conserved and derived characteristics of SCPPs in the coelacanth and other vertebrates. Notably, acidic SCPPs independently evolved various acidic repeats in different lineages, while maintaining high acidity, presumably important for interactions with calcium. Furthermore, the three Pro/Gln-rich SCPP genes, required for mineralizing enamel matrix and confirmed only in tetrapods, were all identified in the coelacanth, strongly suggesting that enamel is equivalent in the coelacanth and tetrapods. This finding corroborates the previous proposition that true enamel evolved much earlier than the origin of tetrapods.
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18
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Gasse B, Chiari Y, Silvent J, Davit-Béal T, Sire JY. Amelotin: an enamel matrix protein that experienced distinct evolutionary histories in amphibians, sauropsids and mammals. BMC Evol Biol 2015; 15:47. [PMID: 25884299 PMCID: PMC4373244 DOI: 10.1186/s12862-015-0329-x] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/17/2014] [Accepted: 02/24/2015] [Indexed: 01/21/2023] Open
Abstract
Background Amelotin (AMTN) is an ameloblast-secreted protein that belongs to the secretory calcium-binding phosphoprotein (SCPP) family, which originated in early vertebrates. In rodents, AMTN is expressed during the maturation stage of amelogenesis only. This expression pattern strongly differs from the spatiotemporal expression of other ameloblast-secreted SCPPs, such as the enamel matrix proteins (EMPs). Furthermore, AMTN was characterized in rodents only. In this study, we applied various approaches, including in silico screening of databases, PCRs and transcriptome sequencing to characterize AMTN sequences in sauropsids and amphibians, and compared them to available mammalian and coelacanth sequences. Results We showed that (i) AMTN is tooth (enamel) specific and underwent pseudogenization in toothless turtles and birds, and (ii) the AMTN structure changed during tetrapod evolution. To infer AMTN function, we studied spatiotemporal expression of AMTN during amelogenesis in a salamander and a lizard, and compared the results with available expression data from mouse. We found that AMTN is expressed throughout amelogenesis in non-mammalian tetrapods, in contrast to its expression limited to enamel maturation in rodents. Conclusions Taken together our findings suggest that AMTN was primarily an EMP. Its functions were conserved in amphibians and sauropsids while a change occurred early in the mammalian lineage, modifying its expression pattern during amelogenesis and its gene structure. These changes likely led to a partial loss of AMTN function and could have a link with the emergence of prismatic enamel in mammals. Electronic supplementary material The online version of this article (doi:10.1186/s12862-015-0329-x) contains supplementary material, which is available to authorized users.
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Affiliation(s)
- Barbara Gasse
- Institut de Biologie Paris-Seine, Université Pierre et Marie Curie, Evolution Paris-Seine, Paris, UMR7138, France.
| | - Ylenia Chiari
- Department of Biology, University of South Alabama, Mobile, AL, 36688, USA.
| | - Jérémie Silvent
- Institut de Biologie Paris-Seine, Université Pierre et Marie Curie, Evolution Paris-Seine, Paris, UMR7138, France. .,Department of Structural Biology, Weizmann Institute of Science, Rehovot, 76100, Israel.
| | - Tiphaine Davit-Béal
- Institut de Biologie Paris-Seine, Université Pierre et Marie Curie, Evolution Paris-Seine, Paris, UMR7138, France.
| | - Jean-Yves Sire
- Institut de Biologie Paris-Seine, Université Pierre et Marie Curie, Evolution Paris-Seine, Paris, UMR7138, France.
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Rashid DJ, Chapman SC, Larsson HC, Organ CL, Bebin AG, Merzdorf CS, Bradley R, Horner JR. From dinosaurs to birds: a tail of evolution. EvoDevo 2014; 5:25. [PMID: 25621146 PMCID: PMC4304130 DOI: 10.1186/2041-9139-5-25] [Citation(s) in RCA: 24] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/02/2014] [Accepted: 07/10/2014] [Indexed: 01/09/2023] Open
Abstract
A particularly critical event in avian evolution was the transition from long- to short-tailed birds. Primitive bird tails underwent significant alteration, most notably reduction of the number of caudal vertebrae and fusion of the distal caudal vertebrae into an ossified pygostyle. These changes, among others, occurred over a very short evolutionary interval, which brings into focus the underlying mechanisms behind those changes. Despite the wealth of studies delving into avian evolution, virtually nothing is understood about the genetic and developmental events responsible for the emergence of short, fused tails. In this review, we summarize the current understanding of the signaling pathways and morphological events that contribute to tail extension and termination and examine how mutations affecting the genes that control these pathways might influence the evolution of the avian tail. To generate a list of candidate genes that may have been modulated in the transition to short-tailed birds, we analyzed a comprehensive set of mouse mutants. Interestingly, a prevalent pleiotropic effect of mutations that cause fused caudal vertebral bodies (as in the pygostyles of birds) is tail truncation. We identified 23 mutations in this class, and these were primarily restricted to genes involved in axial extension. At least half of the mutations that cause short, fused tails lie in the Notch/Wnt pathway of somite boundary formation or differentiation, leading to changes in somite number or size. Several of the mutations also cause additional bone fusions in the trunk skeleton, reminiscent of those observed in primitive and modern birds. All of our findings were correlated to the fossil record. An open question is whether the relatively sudden appearance of short-tailed birds in the fossil record could be accounted for, at least in part, by the pleiotropic effects generated by a relatively small number of mutational events.
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Affiliation(s)
- Dana J Rashid
- Museum of the Rockies, Montana State University, 600 West Kagy Blvd, Bozeman, MT 59717, USA
| | - Susan C Chapman
- Department of Biological Sciences, Clemson University, 340 Long Hall, Clemson, SC 29634, USA
| | - Hans Ce Larsson
- Redpath Museum, McGill University, 859 Sherbrooke Street W., Montreal, Quebec H3A 0C4, Canada
| | - Chris L Organ
- Museum of the Rockies, Montana State University, 600 West Kagy Blvd, Bozeman, MT 59717, USA ; Department of Earth Sciences, Montana State University, 226 Traphagen Hall, Bozeman, MT 59717, USA
| | - Anne-Gaelle Bebin
- Museum of the Rockies, Montana State University, 600 West Kagy Blvd, Bozeman, MT 59717, USA ; Current address: Vaccine and Gene Therapy FL, 9801 Discovery Way, Port Lucie, FL 34987, USA
| | - Christa S Merzdorf
- Department of Cell Biology & Neuroscience, Montana State University, 513 Leon Johnson Hall, Bozeman, MT 59717, USA
| | - Roger Bradley
- Department of Cell Biology & Neuroscience, Montana State University, 513 Leon Johnson Hall, Bozeman, MT 59717, USA
| | - John R Horner
- Museum of the Rockies, Montana State University, 600 West Kagy Blvd, Bozeman, MT 59717, USA
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Chaussain C, Bouazza N, Gasse B, Laffont AG, Opsahl Vital S, Davit-Béal T, Moulis E, Chabadel O, Hennequin M, Courson F, Droz D, Vaysse F, Laboux O, Tassery H, Carel JC, Alcais A, Treluyer JM, Beldjord C, Sire JY. Dental caries and enamelin haplotype. J Dent Res 2014; 93:360-5. [PMID: 24487377 DOI: 10.1177/0022034514522060] [Citation(s) in RCA: 27] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/06/2023] Open
Abstract
In the literature, the enamelin gene ENAM has been repeatedly designated as a possible candidate for caries susceptibility. Here, we checked whether ENAM variants could increase caries susceptibility. To this aim, we sequenced coding exons and exon-intron boundaries of ENAM in 250 children with a severe caries phenotype and in 149 caries-free patients from 9 French hospital groups. In total, 23 single-nucleotide polymorphisms (SNPs) were found, but none appeared to be responsible for a direct change of ENAM function. Six SNPs had a high minor allele frequency (MAF) and 6 others were identified for the first time. Statistical and evolutionary analyses showed that none of these SNPs was associated with caries susceptibility or caries protection when studied separately and challenged with environmental factors. However, haplotype interaction analysis showed that the presence, in a same variant, of 2 exonic SNPs (rs7671281 and rs3796704; MAF 0.12 and 0.10, respectively), both changing an amino acid in the protein region encoded by exon 10 (p.I648T and p.R763Q, respectively), increased caries susceptibility 2.66-fold independent of the environmental risk factors. These findings support ENAM as a gene candidate for caries susceptibility in the studied population.
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Affiliation(s)
- C Chaussain
- AP-HP, Service Odontologie Bretonneau - Louis Mourier HUPNVS and Centre de référence des maladies du métabolisme du phosphore et du calcium, Paris, France
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Bartlett JD. Dental enamel development: proteinases and their enamel matrix substrates. ISRN DENTISTRY 2013; 2013:684607. [PMID: 24159389 PMCID: PMC3789414 DOI: 10.1155/2013/684607] [Citation(s) in RCA: 109] [Impact Index Per Article: 9.9] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 06/27/2013] [Accepted: 07/15/2013] [Indexed: 12/31/2022]
Abstract
This review focuses on recent discoveries and delves in detail about what is known about each of the proteins (amelogenin, ameloblastin, and enamelin) and proteinases (matrix metalloproteinase-20 and kallikrein-related peptidase-4) that are secreted into the enamel matrix. After an overview of enamel development, this review focuses on these enamel proteins by describing their nomenclature, tissue expression, functions, proteinase activation, and proteinase substrate specificity. These proteins and their respective null mice and human mutations are also evaluated to shed light on the mechanisms that cause nonsyndromic enamel malformations termed amelogenesis imperfecta. Pertinent controversies are addressed. For example, do any of these proteins have a critical function in addition to their role in enamel development? Does amelogenin initiate crystallite growth, does it inhibit crystallite growth in width and thickness, or does it do neither? Detailed examination of the null mouse literature provides unmistakable clues and/or answers to these questions, and this data is thoroughly analyzed. Striking conclusions from this analysis reveal that widely held paradigms of enamel formation are inadequate. The final section of this review weaves the recent data into a plausible new mechanism by which these enamel matrix proteins support and promote enamel development.
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Affiliation(s)
- John D. Bartlett
- Harvard School of Dental Medicine & Chair, Department of Mineralized Tissue Biology, The Forsyth Institute, 245 First Street, Cambridge MA 02142, USA
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22
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Silvent J, Sire JY, Delgado S. The dentin matrix acidic phosphoprotein 1 (DMP1) in the light of mammalian evolution. J Mol Evol 2013; 76:59-70. [PMID: 23361408 DOI: 10.1007/s00239-013-9539-2] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/03/2012] [Accepted: 01/06/2013] [Indexed: 12/17/2022]
Abstract
Dentin matrix acidic phosphoprotein 1 (DMP1) is an acidic, highly phosphorylated, noncollagenous protein secreted during dentin and bone formation. Previous functional studies of DMP1 have revealed various motifs playing a role in either mineralization or cell differentiation. We performed an evolutionary analysis of DMP1 to identify residues and motifs that were conserved during 220 millions years (Ma) of mammalian evolution, and hence have an important function. In silico search provided us with 41 sequences that were aligned and analyzed using the Hyphy program. We showed that DMP1 contains 55 positions that were kept unchanged for 220 Ma. We also defined in a more precise manner some motifs that were already known (i.e., cleavage sites, RGD motif, ASARM peptide, glycosaminoglycan chain attachment site, nuclear localization signal sites, and dentin sialophosphoprotein-binding site), and we found five, highly conserved, new functional motifs. In the near future, functional studies could be performed to understand the role played by them.
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23
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Meredith RW, Gatesy J, Springer MS. Molecular decay of enamel matrix protein genes in turtles and other edentulous amniotes. BMC Evol Biol 2013; 13:20. [PMID: 23342979 PMCID: PMC3562159 DOI: 10.1186/1471-2148-13-20] [Citation(s) in RCA: 43] [Impact Index Per Article: 3.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/30/2012] [Accepted: 01/16/2013] [Indexed: 11/20/2022] Open
Abstract
Background Secondary edentulism (toothlessness) has evolved on multiple occasions in amniotes including several mammalian lineages (pangolins, anteaters, baleen whales), birds, and turtles. All edentulous amniote clades have evolved from ancestors with enamel-capped teeth. Previous studies have documented the molecular decay of tooth-specific genes in edentulous mammals, all of which lost their teeth in the Cenozoic, and birds, which lost their teeth in the Cretaceous. By contrast with mammals and birds, tooth loss in turtles occurred in the Jurassic (201.6-145.5 Ma), providing an extended time window for tooth gene degradation in this clade. The release of the painted turtle and Chinese softshell turtle genomes provides an opportunity to recover the decayed remains of tooth-specific genes in Testudines. Results We queried available genomes of Testudines (Chrysemys picta [painted turtle], Pelodiscus sinensis [Chinese softshell turtle]), Aves (Anas platyrhynchos [duck], Gallus gallus [chicken], Meleagris gallopavo [turkey], Melopsittacus undulatus [budgerigar], Taeniopygia guttata [zebra finch]), and enamelless mammals (Orycteropus afer [aardvark], Choloepus hoffmanni [Hoffmann’s two-toed sloth], Dasypus novemcinctus [nine-banded armadillo]) for remnants of three enamel matrix protein (EMP) genes with putative enamel-specific functions. Remnants of the AMBN and ENAM genes were recovered in Chrysemys and retain their original synteny. Remnants of AMEL were recovered in both testudines, although there are no shared frameshifts. We also show that there are inactivated copies of AMBN, AMEL and ENAM in representatives of divergent avian lineages including Galloanserae, Passeriformes, and Psittaciformes, and that there are shared frameshift mutations in all three genes that predate the basal split in Neognathae. Among enamelless mammals, all three EMP genes exhibit inactivating mutations in Orycteropus and Choloepus. Conclusions Our results highlight the power of combining fossil and genomic evidence to decipher macroevolutionary transitions and characterize the functional range of different loci involved in tooth development. The fossil record and phylogenetics combine to predict the occurrence of molecular fossils of tooth-specific genes in the genomes of edentulous amniotes, and in every case these molecular fossils have been discovered. The widespread occurrence of EMP pseudogenes in turtles, birds, and edentulous/enamelless mammals also provides compelling evidence that in amniotes, the only unique, non-redundant function of these genes is in enamel formation.
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Affiliation(s)
- Robert W Meredith
- Department of Biology, University of California, Riverside, CA 92521, USA
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24
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Bodyweight assessment of enamelin null mice. BIOMED RESEARCH INTERNATIONAL 2012; 2013:246861. [PMID: 23509695 PMCID: PMC3591218 DOI: 10.1155/2013/246861] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 08/21/2012] [Revised: 10/17/2012] [Accepted: 10/22/2012] [Indexed: 11/18/2022]
Abstract
The Enam null mice appear to be smaller than wild-type mice, which prompted the hypothesis that enamel defects negatively influence nutritional intake and bodyweight gain (BWG). We compared the BWG of Enam−/− and wild-type mice from birth (D0) to Day 42 (D42). Wild-type (WT) and Enam−/− (N) mice were given either hard chow (HC) or soft chow (SC). Four experimental groups were studied: WTHC, WTSC, NHC, and NSC. The mother's bodyweight (DBW) and the average litter bodyweight (ALBW) were obtained from D0 to D21. After D21, the pups were separated from the mother and provided the same type of food. Litter bodyweights were measured until D42. ALBW was compared at 7-day intervals using one-way ANOVA, while the influence of DBW on ALBW was analyzed by mixed-model analyses. The ALBW of Enam−/− mice maintained on hard chow (NHC) was significantly lower than the two WT groups at D21 and the differences persisted into young adulthood. The ALBW of Enam−/− mice maintained on soft chow (NSC) trended lower, but was not significantly different than that of the WT groups. We conclude that genotype, which affects enamel integrity, and food hardness influence bodyweight gain in postnatal and young adult mice.
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Gasse B, Silvent J, Sire JY. Evolutionary analysis suggests that AMTN is enamel-specific and a candidate for AI. J Dent Res 2012; 91:1085-9. [PMID: 22968158 DOI: 10.1177/0022034512460551] [Citation(s) in RCA: 36] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/23/2023] Open
Abstract
Molecular evolutionary analysis is an efficient method to predict and/or validate amino acid substitutions that could lead to a genetic disease and to highlight residues and motifs that could play an important role in the protein structure and/or function. We have applied such analysis to amelotin (AMTN), a recently identified enamel protein in the rat, mouse, and humans. An in silico search for AMTN provided 42 new mammalian sequences that were added to the 3 published sequences with which we performed the analysis using a dataset representative of all lineages (circa 220 million years of evolution), including 2 enamel-less species, sloth and armadillo. During evolution, of the 209 residues of human AMTN, 17 were unchanged and 34 had conserved their chemical properties. Substituting these important residues could lead to amelogenesis imperfecta (AI). Also, AMTN possesses a well-conserved signal peptide, 2 conserved motifs whose function is certainly important but unknown, and a putative phosphorylation site (SXE). In addition, the sequences of the 2 enamel-less species display mutations revealing that AMTN underwent pseudogenization, which suggests that AMTN is an enamel-specific protein.
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Affiliation(s)
- B Gasse
- Université Pierre et Marie Curie, UMR 7138, EDS research group, 7 quai St-Bernard, Case 5, 75005 Paris, France
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26
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Tokita M, Chaeychomsri W, Siruntawineti J. Developmental basis of toothlessness in turtles: insight into convergent evolution of vertebrate morphology. Evolution 2012; 67:260-73. [PMID: 23289576 DOI: 10.1111/j.1558-5646.2012.01752.x] [Citation(s) in RCA: 34] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/28/2022]
Abstract
The tooth is a major component of the vertebrate feeding apparatus and plays a crucial role in species survival, thus subjecting tooth developmental programs to strong selective constraints. However, irrespective of their functional importance, teeth have been lost in multiple lineages of tetrapod vertebrates independently. To understand both the generality and the diversity of developmental mechanisms that cause tooth agenesis in tetrapods, we investigated expression patterns of a series of tooth developmental genes in the lower jaw of toothless turtles and compared them to that of toothed crocodiles and the chicken as a representative of toothless modern birds. In turtle embryos, we found impairment of Shh signaling in the oral epithelium and early-stage arrest of odontoblast development caused by termination of Msx2 expression in the dental mesenchyme. Our data indicate that such changes underlie tooth agenesis in turtles and suggest that the mechanism that leads to early-stage odontogenic arrest differs between birds and turtles. Our results demonstrate that the cellular and molecular mechanisms that regulate early-stage arrest of tooth development are diverse in tetrapod lineages, and odontogenic developmental programs may respond to changes in upstream molecules similarly thereby evolving convergently with feeding morphology.
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Affiliation(s)
- Masayoshi Tokita
- Graduate School of Life and Environmental Sciences, University of Tsukuba, Tenno-dai 1-1-1, Tsukuba, Ibaraki 305-8572, Japan.
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27
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Abstract
Dental enamel is a hypermineralized tissue, containing only trace amounts of organic components. During enamel formation, matrix metalloproteinase 20 (MMP20) processes proteins comprising enamel matrix and facilitates hypermineralization. In the human genome, 24 distinct MMP genes have been identified. Among these genes, MMP20 is clustered with eight other genes, including MMP13, and all these clustered genes show phylogenetically close relationships. In this study, we investigated MMP20 and closely related MMP genes in various tetrapods and in a teleost fish, fugu. In the genome of the chicken, a toothless tetrapod, we identified degraded exons of MMP20, which supports the previous proposition that MMP20 is important specifically for enamel formation. Nevertheless, for unknown reasons, we failed to identify MMP20 in the platypus genome. In the opossum, lizard, and frog genomes, MMP20 was found clustered with MMP13. Furthermore, in the fugu genome, we identified an MMP20-like gene located adjacent to MMP13, suggesting that MMP20 arose before the divergence of ray-finned fish and lobe-finned fish. The teleost tooth surface is covered with enameloid, a hypermineralized tissue different from enamel. Thus, we hypothesize that MMP20 could have been used in an ancient hypermineralized tissue, which evolved into enameloid in teleosts and into enamel in tetrapods.
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Affiliation(s)
- Kazuhiko Kawasaki
- Department of Anthropology, Pennsylvania State University, University Park, PA 16802, USA.
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28
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Hu JCC, Lertlam R, Richardson AS, Smith CE, McKee MD, Simmer JP. Cell proliferation and apoptosis in enamelin null mice. Eur J Oral Sci 2012; 119 Suppl 1:329-37. [PMID: 22243264 DOI: 10.1111/j.1600-0722.2011.00860.x] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/13/2023]
Abstract
Enamelin is a secreted glycoprotein that is critical for dental enamel formation. Ameloblasts in enamelin (Enam) null mice develop atypical features that include the absence of a Tomes' process, expanded endoplasmic reticulum, apparent loss of polarity, and pooling of extracellular matrix in all directions, including between ameloblasts and the stratum intermedium. We hypothesized that ameloblast pathological changes may be associated with increased cell apoptosis. Our objective was to assess apoptotic activity in maxillary first molars of wild-type, Enam(+/-), and Enam(-/-) mice at postnatal days 5, 7, 9, 14, and 17. Mouse maxillae were characterized by light microscopy after terminal deoxynucleotidyl transferase (TdT)-mediated biotin-dUTP nick-end labelling (TUNEL) or 5-bromo-2'-deoxyuridine (BrdU) staining. Following the initial deposition of dentin matrix, ameloblasts became highly dysplastic and no enamel crystal ribbons were deposited. Ameloblast apoptosis was observed in the Enam null mice starting in the secretory stage and with no apparent alteration in cell proliferation. We conclude that in the absence of enamelin and subsequent shutdown of enamel formation, ameloblasts undergo pathological changes early in the secretory stage that are evident as radically altered cell morphology, detachment from the tooth surface, apoptosis, and formation of ectopic calcifications both outside and inside the dystrophic enamel organ.
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Affiliation(s)
- Jan C-C Hu
- Department of Biologic and Materials Sciences, University of Michigan School of Dentistry, Ann Arbor, MI 48108, USA.
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29
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30
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Louchart A, Viriot L. From snout to beak: the loss of teeth in birds. Trends Ecol Evol 2011; 26:663-73. [DOI: 10.1016/j.tree.2011.09.004] [Citation(s) in RCA: 73] [Impact Index Per Article: 5.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/18/2011] [Revised: 09/02/2011] [Accepted: 09/05/2011] [Indexed: 11/25/2022]
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31
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Chan HC, Estrella NMRP, Milkovich RN, Kim JW, Simmer JP, Hu JCC. Target gene analyses of 39 amelogenesis imperfecta kindreds. Eur J Oral Sci 2011; 119 Suppl 1:311-23. [PMID: 22243262 PMCID: PMC3292789 DOI: 10.1111/j.1600-0722.2011.00857.x] [Citation(s) in RCA: 63] [Impact Index Per Article: 4.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Abstract
Previously, mutational analyses identified six disease-causing mutations in 24 amelogenesis imperfecta (AI) kindreds. We have since expanded the number of AI kindreds to 39, and performed mutation analyses covering the coding exons and adjoining intron sequences for the six proven AI candidate genes [amelogenin (AMELX), enamelin (ENAM), family with sequence similarity 83, member H (FAM83H), WD repeat containing domain 72 (WDR72), enamelysin (MMP20), and kallikrein-related peptidase 4 (KLK4)] and for ameloblastin (AMBN) (a suspected candidate gene). All four of the X-linked AI families (100%) had disease-causing mutations in AMELX, suggesting that AMELX is the only gene involved in the aetiology of X-linked AI. Eighteen families showed an autosomal-dominant pattern of inheritance. Disease-causing mutations were identified in 12 (67%): eight in FAM83H, and four in ENAM. No FAM83H coding-region or splice-junction mutations were identified in three probands with autosomal-dominant hypocalcification AI (ADHCAI), suggesting that a second gene may contribute to the aetiology of ADHCAI. Six families showed an autosomal-recessive pattern of inheritance, and disease-causing mutations were identified in three (50%): two in MMP20, and one in WDR72. No disease-causing mutations were found in 11 families with only one affected member. We conclude that mutation analyses of the current candidate genes for AI have about a 50% chance of identifying the disease-causing mutation in a given kindred.
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Affiliation(s)
- Hui-Chen Chan
- Department of Biologic and Materials Sciences, University of Michigan School of Dentistry, Ann Arbor, MI, USA
| | - Ninna M. R. P. Estrella
- Department of Orthodontics and Pediatric Dentistry, University of Michigan School of Dentistry, Ann Arbor, MI, USA
| | - Rachel N. Milkovich
- Department of Biologic and Materials Sciences, University of Michigan School of Dentistry, Ann Arbor, MI, USA
| | - Jung-Wook Kim
- Department of Pediatric Dentistry & Dental Research Institute, School of Dentistry, Seoul National University, Seoul, Korea
| | - James P. Simmer
- Department of Biologic and Materials Sciences, University of Michigan School of Dentistry, Ann Arbor, MI, USA
| | - Jan C-C. Hu
- Department of Biologic and Materials Sciences, University of Michigan School of Dentistry, Ann Arbor, MI, USA
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Yamakoshi Y, Yamakoshi F, Hu JCC, Simmer JP. Characterization of kallikrein-related peptidase 4 glycosylations. Eur J Oral Sci 2011; 119 Suppl 1:234-40. [PMID: 22243251 PMCID: PMC3282036 DOI: 10.1111/j.1600-0722.2011.00863.x] [Citation(s) in RCA: 12] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/21/2022]
Abstract
Kallikrein-related peptidase 4 (KLK4) is a glycosylated serine protease that functions in the maturation (hardening) of dental enamel. Pig and mouse KLK4 contain three potential N-glycosylation sites. We isolated KLK4 from developing pig and mouse molars and characterized their N-glycosylations. N-glycans were enzymatically released by digestion with N-glycosidase F and fluorescently labeled with 2-aminobenzoic acid. Normal-phase high-performance liquid chromatography (NP-HPLC) revealed N-glycans with no, or with one, two, or three sialic acid attachments in pig KLK4 and with no, or with one or two sialic acid attachments in mouse KLK4. The labeled N-glycans were digested with sialidase to generate the asialo N-glycan cores that were fractionated by reverse-phase HPLC, and their retention times were compared with similarly labeled glycan standards. The purified cores were characterized by mass spectrometric and monosaccharide composition analyses. We determined that pig and mouse KLK4 have NA2 and NA2F biantennary N-glycan cores. The pig triantennary core is NA3. The mouse triantennary core is NA3 with a fucose connected by an α1-6 linkage, indicating that it is attached to the first N-acetyglucosamine (NA3F). We conclude that pig KLK4 has NA2, NA2F, and NA3 N-glycan cores with no, or with one, two, or three sialic acids. Mouse KLK4 has NA2, NA2F, and NA3F N-glycan cores with no, or with one or two sialic acids.
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Affiliation(s)
- Yasuo Yamakoshi
- Department of Biologic and Materials Sciences, University of Michigan School of Dentistry, Eisenhower Place, Ann Arbor, MI 48108, USA
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Kawasaki K, Lafont AG, Sire JY. The Evolution of Milk Casein Genes from Tooth Genes before the Origin of Mammals. Mol Biol Evol 2011; 28:2053-61. [DOI: 10.1093/molbev/msr020] [Citation(s) in RCA: 79] [Impact Index Per Article: 6.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/07/2023] Open
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34
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Kawasaki K. The SCPP Gene Family and the Complexity of Hard Tissues in Vertebrates. Cells Tissues Organs 2011; 194:108-12. [DOI: 10.1159/000324225] [Citation(s) in RCA: 57] [Impact Index Per Article: 4.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/20/2022] Open
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35
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Pavlopoulou A, Pampalakis G, Michalopoulos I, Sotiropoulou G. Evolutionary history of tissue kallikreins. PLoS One 2010; 5:e13781. [PMID: 21072173 PMCID: PMC2967472 DOI: 10.1371/journal.pone.0013781] [Citation(s) in RCA: 43] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/02/2010] [Accepted: 10/08/2010] [Indexed: 12/12/2022] Open
Abstract
The gene family of human kallikrein-related peptidases (KLKs) encodes proteins with diverse and pleiotropic functions in normal physiology as well as in disease states. Currently, the most widely known KLK is KLK3 or prostate-specific antigen (PSA) that has applications in clinical diagnosis and monitoring of prostate cancer. The KLK gene family encompasses the largest contiguous cluster of serine proteases in humans which is not interrupted by non-KLK genes. This exceptional and unique characteristic of KLKs makes them ideal for evolutionary studies aiming to infer the direction and timing of gene duplication events. Previous studies on the evolution of KLKs were restricted to mammals and the emergence of KLKs was suggested about 150 million years ago (mya). In order to elucidate the evolutionary history of KLKs, we performed comprehensive phylogenetic analyses of KLK homologous proteins in multiple genomes including those that have been completed recently. Interestingly, we were able to identify novel reptilian, avian and amphibian KLK members which allowed us to trace the emergence of KLKs 330 mya. We suggest that a series of duplication and mutation events gave rise to the KLK gene family. The prominent feature of the KLK family is that it consists of tandemly and uninterruptedly arrayed genes in all species under investigation. The chromosomal co-localization in a single cluster distinguishes KLKs from trypsin and other trypsin-like proteases which are spread in different genetic loci. All the defining features of the KLKs were further found to be conserved in the novel KLK protein sequences. The study of this unique family will further assist in selecting new model organisms for functional studies of proteolytic pathways involving KLKs.
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Affiliation(s)
- Athanasia Pavlopoulou
- Department of Pharmacy, School of Health Sciences, University of Patras, Rion-Patras, Greece
| | - Georgios Pampalakis
- Department of Pharmacy, School of Health Sciences, University of Patras, Rion-Patras, Greece
| | | | - Georgia Sotiropoulou
- Department of Pharmacy, School of Health Sciences, University of Patras, Rion-Patras, Greece
- * E-mail:
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