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Parker WMG, Adams JW, Campbell EJ, Coulson G, Sanson GD, Evans AR. Evergrowing incisors of diprotodont marsupials record age and life history. Arch Oral Biol 2024; 165:106018. [PMID: 38870611 DOI: 10.1016/j.archoralbio.2024.106018] [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: 02/24/2024] [Revised: 05/22/2024] [Accepted: 05/28/2024] [Indexed: 06/15/2024]
Abstract
OBJECTIVE Tooth growth and wear are commonly used tools for determining the age of mammals. The most speciose order of marsupials, Diprotodontia, is characterised by a pair of procumbent incisors within the lower jaw. This study examines the growth and wear of these incisors to understand their relationship with age and sex. DESIGN Measurements of mandibular incisor crown and root length were made for two sister species of macropodid (kangaroos and wallabies); Macropus giganteus and Macropus fuliginosus. Histological analysis examined patterns of dentine and cementum deposition within these teeth. Broader generalisability within Diprotodontia was tested using dentally reduced Tarsipes rostratus - a species disparate in body size and incisor function to the studied macropodids. RESULTS In the macropodid sample it is demonstrated that the hypsodont nature of these incisors makes measurements of their growth (root length) and wear (crown length) accurate indicators of age and sex. Model fitting finds that root growth proceeds according to a logarithmic function across the lifespan, while crown wear follows a pattern of exponential reduction for both macropodid species. Histological results find that secondary dentine deposition and cementum layering are further indicators of age. Incisor measurements are shown to correlate with age in the sample of T. rostratus. CONCLUSIONS The diprotodontian incisor is a useful tool for examining chronological age and sex, both morphologically and microstructurally. This finding has implications for population ecology, palaeontology and marsupial evolution.
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Affiliation(s)
- William M G Parker
- School of Biological Sciences, Monash University, Melbourne, Victoria 3800, Australia; Geosciences, Museums Victoria, Melbourne, Victoria 3001, Australia.
| | - Justin W Adams
- Biomedicine Discovery Institute, Monash University, Melbourne, Victoria 3800, Australia; Geosciences, Museums Victoria, Melbourne, Victoria 3001, Australia
| | - Eliza J Campbell
- School of Biological Sciences, Monash University, Melbourne, Victoria 3800, Australia
| | - Graeme Coulson
- School of BioSciences, The University of Melbourne, Melbourne, Victoria 3010, Australia
| | - Gordon D Sanson
- School of Biological Sciences, Monash University, Melbourne, Victoria 3800, Australia
| | - Alistair R Evans
- School of Biological Sciences, Monash University, Melbourne, Victoria 3800, Australia; Geosciences, Museums Victoria, Melbourne, Victoria 3001, Australia
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Emken S, Witzel C, Kierdorf U, Frölich K, Kierdorf H. A labeling study of dentin formation rates during crown and root growth of porcine mandibular first molars. Anat Rec (Hoboken) 2024; 307:2103-2120. [PMID: 38051150 DOI: 10.1002/ar.25358] [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: 10/01/2023] [Revised: 11/14/2023] [Accepted: 11/15/2023] [Indexed: 12/07/2023]
Abstract
We used fluorochrome labeling to study spatiotemporal variation of dentin apposition (DAR) and extension (DER) rates during crown and root formation of mandibular first molars from wild boar and domestic pigs. DAR was reconstructed along the course of dentinal tubules in four zones of the crown and in the upper root area. In all five zones, mean DAR increased during the first 30% to 40% of apposition, reaching highest values (22-23 μm/day) in the upper-lateral crown zone. Lowest values were recorded near the dentin-pulp interface (DPI). Typically, DARs in contemporaneously formed dentin areas were higher in more cuspally compared to more cervically/apically located zones. DER was high (>200 μm/day) in early postnatal crown dentin and then decreased markedly in cervical direction, with lowest values in the cervical crown zone. After this nadir, DER sharply increased in the upper 30% to 40% of the root extension, reaching values equaling (wild boar) or even surpassing (domestic pigs) those recorded in the upper lateral crown. After this peak, DER again decreased. While DAR did not differ markedly between wild boar and domestic pigs, the DER showed marked differences, both regarding maximum values (208.1 μm/day in wild boar, 272.2 μm/day in domestic pigs) and the timing of the root growth spurt, which occurred earlier in the domestic pigs. We consider the more rapid recruitment of secretory odontoblasts in domestic pigs (reflected by higher DER) a side effect of selection for rapid body growth during pig domestication.
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Affiliation(s)
- Simon Emken
- Department of Biology, University of Hildesheim, Hildesheim, Germany
| | - Carsten Witzel
- Department of Biology, University of Hildesheim, Hildesheim, Germany
| | - Uwe Kierdorf
- Department of Biology, University of Hildesheim, Hildesheim, Germany
| | - Kai Frölich
- Department of Biology, University of Hildesheim, Hildesheim, Germany
- Tierpark Arche Warder e.V., Warder, Germany
| | - Horst Kierdorf
- Department of Biology, University of Hildesheim, Hildesheim, Germany
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Green DR, Winkler DE, Leichliter JN, Harms GS, Hatt JM, Clauss M, Tütken T. Formation and Replacement of Bone and Tooth Mineralized Tissues in Green Iguanas (Iguana iguana) Revealed by In-Vivo Fluorescence Marking. Integr Comp Biol 2023; 63:515-529. [PMID: 37475667 DOI: 10.1093/icb/icad089] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/21/2023] [Revised: 06/15/2023] [Accepted: 06/20/2023] [Indexed: 07/22/2023] Open
Abstract
Hard tissue formation patterns and rates reveal details of animal physiology, life history, and environment, but are understudied in reptiles. Here, we use fluorescence labels delivered in vivo and laser confocal scanning microscopy to study tooth and bone formation in a managed group of green iguanas (Iguana iguana, Linné 1758) kept for 1.5 years under experimentally controlled conditions and undergoing several dietary switches. We constrain rates of tooth elongation, which we observe to be slow when enamel is initially deposited (c. 9 µm/day), but then increases exponentially in the dentin root, reaching c. 55 µm/day or more after crown completion. We further constrain the total timing of tooth formation to ∼40-60 days, and observe highly variable timings of tooth resorption onset and replacement. Fluorescent labels clearly indicate cohorts of teeth recruited within Zahnreihen replacement waves, with faster sequential tooth recruitment and greater wave sizes posteriorly, where each wave initiates. Fluorescence further reveals enamel maturation after initial deposition. Rates of hard tissue formation in long bones range from 0.4 to 3.4 µm/day, correlating with animal weight gain and cortical bone recording the entire history of the experiment. We suggest additional labeling experiments to study hard tissue formation patterns in other reptiles, and propose strategies for chemical analyses of hard tissues in order to extract temporal information about past environments, behaviors, and diets from reptilian fossils throughout the Phanerozoic.
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Affiliation(s)
- Daniel R Green
- Lamont-Doherty Earth Observatory, Climate School, Columbia University, 2910 Broadway Level A, New York, NY 10025, USA
| | - Daniela E Winkler
- Applied and Analytical Palaeontology, Institute of Geosciences, Johannes Gutenberg University, J.-J.-Becher-Weg 21, 55128 Mainz, Germany
- Zoological Institute, Christian-Albrechts-Universität zu Kiel, Am Botanischen Garten 1-9, 24118 Kiel, Germany
| | - Jennifer N Leichliter
- Applied and Analytical Palaeontology, Institute of Geosciences, Johannes Gutenberg University, J.-J.-Becher-Weg 21, 55128 Mainz, Germany
- Emmy Noether Group for Hominin Meat Consumption, Max Planck Institute for Chemistry, 55128 Mainz, Germany
| | - Gregory S Harms
- Imaging Core Facility, University Medical Center Mainz, Langenbeckstraße 1, 55131 Mainz, Germany
- Departments of Biology and Earth Systems Science and Mathematics, Physics and Computer Science, WIlkes University, Wilkes-Barre, PA 18766, USA
| | - Jean-Michel Hatt
- Clinic for Zoo Animals, Exotic Pets and Wildlife, Vetsuisse Faculty, University of Zürich, Winterthurerstrasse 260, 8057 Zurich, Switzerland
| | - Marcus Clauss
- Clinic for Zoo Animals, Exotic Pets and Wildlife, Vetsuisse Faculty, University of Zürich, Winterthurerstrasse 260, 8057 Zurich, Switzerland
| | - Thomas Tütken
- Applied and Analytical Palaeontology, Institute of Geosciences, Johannes Gutenberg University, J.-J.-Becher-Weg 21, 55128 Mainz, Germany
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Emken S, Witzel C, Kierdorf U, Frölich K, Kierdorf H. Wild boar versus domestic pig-Deciphering of crown growth in porcine second molars. J Anat 2023; 242:1078-1095. [PMID: 36774334 PMCID: PMC10184542 DOI: 10.1111/joa.13838] [Citation(s) in RCA: 3] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/06/2022] [Revised: 01/15/2023] [Accepted: 01/18/2023] [Indexed: 02/13/2023] Open
Abstract
Based on the previously established periodicity of enamel growth marks, we reconstructed crown growth parameters of mandibular second molars from two wild boar and two domestic pigs of the Linderöd breed. Body weight gain and progression of dental development were markedly faster in the domestic pigs than the wild boar. While the final crown dimensions of the M2 did not differ between domestic pigs and wild boar, mean crown formation time (CFT) of this tooth was considerably shorter in the domestic pigs (162 days) than in the wild boar (205 days). The difference in CFT was mainly attributable to a higher enamel extension rate (EER) in the domestic pig. Generally, EER was highest in the cuspalmost deciles of the length of the enamel-dentine-junction and markedly dropped in cervical direction, with lowest values occurring in the cervicalmost decile. In consequence, the cuspal half of the M2 crown was formed about three times faster than the cervical half. In contrast to the EER, no marked difference in daily enamel secretion rate (DSR) was recorded between domestic pigs and wild boar. The duration of enamel matrix apposition as well as linear enamel thickness in corresponding crown portions was only slightly lower in the domestic pigs than the wild boar. Thus, the earlier completion of M2 crown growth in the domestic pig was mainly achieved by a higher EER and not by an increased DSR. The more rapid recruitment of secretory ameloblasts in the course of molar crown formation of domestic pigs compared to wild boar is considered a side-effect of the selection for rapid body growth during pig domestication.
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Affiliation(s)
- Simon Emken
- Department of Biology, University of Hildesheim, Hildesheim, Germany
| | - Carsten Witzel
- Department of Biology, University of Hildesheim, Hildesheim, Germany
| | - Uwe Kierdorf
- Department of Biology, University of Hildesheim, Hildesheim, Germany
| | - Kai Frölich
- Department of Biology, University of Hildesheim, Hildesheim, Germany.,Tierpark Arche Warder e.V, Warder, Germany
| | - Horst Kierdorf
- Department of Biology, University of Hildesheim, Hildesheim, Germany
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5
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Nacarino-Meneses C, Chinsamy A. Mineralized-tissue histology reveals protracted life history in the Pliocene three-toed horse from Langebaanweg (South Africa). Zool J Linn Soc 2021. [DOI: 10.1093/zoolinnean/zlab037] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/13/2022]
Abstract
Abstract
We studied the bone and dental histology of the tri-dactyl equid Eurygnathohippus hooijeri, one of the most iconic mammals found at the world-renowned Pliocene site of Langebaanweg, South Africa, to reconstruct important features of its life history. Our results show that key life-history events, such as weaning, skeletal maturity and reproductive maturity, occurred later in this African hipparionine compared with European three-toed equids and several extant Equus. Its late life-history schedule agrees with an ecological context of low adult extrinsic mortality and low juvenile survival rates. We also observed high rates of bone growth in Eu. hooijeri that were probably achieved through a high-quality diet and plentiful available water. Our research highlights the significance of combining bone and dental histology in the same taxon to obtain refined palaeobiological information about extinct vertebrates.
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Affiliation(s)
- Carmen Nacarino-Meneses
- Department of Biological Sciences, University of Cape Town, Private Bag X3, Rhodes Gift, 7700 Cape Town, South Africa
| | - Anusuya Chinsamy
- Department of Biological Sciences, University of Cape Town, Private Bag X3, Rhodes Gift, 7700 Cape Town, South Africa
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6
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Emken S, Witzel C, Kierdorf U, Frölich K, Kierdorf H. Characterization of short-period and long-period incremental markings in porcine enamel and dentine-Results of a fluorochrome labelling study in wild boar and domestic pigs. J Anat 2021; 239:1207-1220. [PMID: 34240412 PMCID: PMC8546513 DOI: 10.1111/joa.13502] [Citation(s) in RCA: 7] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/28/2021] [Revised: 06/13/2021] [Accepted: 06/15/2021] [Indexed: 01/09/2023] Open
Abstract
Mammalian dental hard tissues exhibit incremental markings that reflect the periodic variation of appositional growth rates. In order to use these markings to characterize dental growth processes and to infer life‐history traits, an unequivocal identification of their periodicities is required. We performed a fluorochrome labelling study on forming enamel and dentine in molar teeth of wild boar and domestic pigs to establish the periodicity and temporal correspondence of incremental markings in enamel and dentine. The dominant incremental markings in enamel (laminations) and dentine (von Ebner lines) recorded in the pig teeth are of a daily nature. In addition, long‐period incremental markings with a periodicity of 2 days were recorded in enamel (striae of Retzius) and dentine (Andresen lines). The 2‐day growth rhythm was also expressed at the lateral crown surface, as evidenced by the pattern of perikymata. In enamel, also markings with a sub‐daily periodicity, representing an ultradian growth rhythm, were observed. Our study provides experimental evidence for the periodicity of incremental markings in porcine enamel and dentine. The findings correct previous misconceptions on incremental markings in dental hard tissues of pigs and other ungulates that had led to erroneous conclusions regarding crown formation parameters.
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Affiliation(s)
- Simon Emken
- Department of Biology, University of Hildesheim, Hildesheim, Germany
| | - Carsten Witzel
- Department of Biology, University of Hildesheim, Hildesheim, Germany
| | - Uwe Kierdorf
- Department of Biology, University of Hildesheim, Hildesheim, Germany
| | - Kai Frölich
- Department of Biology, University of Hildesheim, Hildesheim, Germany.,Tierpark Arche Warder e.V, Warder, Germany
| | - Horst Kierdorf
- Department of Biology, University of Hildesheim, Hildesheim, Germany
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7
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Calderón T, Arnold W, Stalder G, Painer J, Köhler M. Labelling experiments in red deer provide a general model for early bone growth dynamics in ruminants. Sci Rep 2021; 11:14074. [PMID: 34234258 PMCID: PMC8263734 DOI: 10.1038/s41598-021-93547-4] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/09/2021] [Accepted: 06/23/2021] [Indexed: 02/08/2023] Open
Abstract
Growth rates importantly determine developmental time and are, therefore, a key variable of a species' life history. A widely used method to reconstruct growth rates and to estimate age at death in extant and particularly in fossil vertebrates is the analysis of bone tissue apposition rates. Lines of arrested growth (LAGs) are of special interest here, as they indicate a halt in bone growth. However, although of great importance, the time intervals between, and particularly the reason of growth arrests remains unknown. Therefore, experiments are increasingly called for to calibrate growth rates with tissue types and life history events, and to provide reliable measurements of the time involved in the formation of LAGs. Based on in vivo bone labelling, we calibrated periods of bone tissue apposition, growth arrest, drift and resorption over the period from birth to post-weaning in a large mammal, the red deer. We found that bone growth rates tightly matched the daily weight gain curve, i.e. decreased with age, with two discrete periods of growth rate disruption that coincided with the life history events birth and weaning, that were visually recognisable in bone tissue as either partial LAGs or annuli. Our study identified for the first time in a large mammal a general pattern for juvenile bone growth rates, including periods of growth arrest. The tight correlation between daily weight gain and bone tissue apposition suggests that the red deer bone growth model is valid for ruminants in general where the daily weight gain curve is comparable.
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Affiliation(s)
- Teresa Calderón
- Institut Català de Paleontologia Miquel Crusafont (ICP), Edifici Z, Universitat Autònoma de Barcelona, C/ de Les Columnes, s/n., 08193, Bellaterra, Barcelona, Spain.
| | - Walter Arnold
- Research Institute of Wildlife Ecology, University of Veterinary Medicine, Vienna, Austria
| | - Gabrielle Stalder
- Research Institute of Wildlife Ecology, University of Veterinary Medicine, Vienna, Austria
| | - Johanna Painer
- Research Institute of Wildlife Ecology, University of Veterinary Medicine, Vienna, Austria
| | - Meike Köhler
- Institut Català de Paleontologia Miquel Crusafont (ICP), Edifici Z, Universitat Autònoma de Barcelona, C/ de Les Columnes, s/n., 08193, Bellaterra, Barcelona, Spain.,ICREA, Pg. Lluís Companys 23, 08010, Barcelona, Spain
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Smith TM, Cook L, Dirks W, Green DR, Austin C. Teeth reveal juvenile diet, health and neurotoxicant exposure retrospectively: What biological rhythms and chemical records tell us. Bioessays 2021; 43:e2000298. [PMID: 33721363 DOI: 10.1002/bies.202000298] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/12/2020] [Revised: 02/09/2021] [Accepted: 02/10/2021] [Indexed: 01/14/2023]
Abstract
Integrated developmental and elemental information in teeth provide a unique framework for documenting breastfeeding histories, physiological disruptions, and neurotoxicant exposure in humans and our primate relatives, including ancient hominins. Here we detail our method for detecting the consumption of mothers' milk and exploring health history through the use of laser ablation-inductively coupled plasma-mass spectrometry (LA-ICP-MS) mapping of sectioned nonhuman primate teeth. Calcium-normalized barium and lead concentrations in tooth enamel and dentine may reflect milk and formula consumption with minimal modification during subsequent tooth mineralization, particularly in dentine. However, skeletal resorption during severe illness, and bioavailable metals in nonmilk foods, can complicate interpretations of nursing behavior. We show that explorations of the patterning of multiple elements may aid in the distinction of these important etiologies. Targeted studies of skeletal chemistry, gastrointestinal maturation, and the dietary bioavailability of metals are needed to optimize these unique records of human health and behavior.
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Affiliation(s)
- Tanya M Smith
- Australian Research Centre for Human Evolution, Griffith University, Nathan, Queensland, Australia.,Griffith Centre for Social and Cultural Research, Griffith University, Nathan, Queensland, Australia
| | - Luisa Cook
- School of Nursing, Midwifery and Social Work, University of Queensland, Saint Lucia, Queensland, Australia
| | - Wendy Dirks
- Department of Anthropology, Durham University, Durham, Durham, UK
| | - Daniel R Green
- Department of Human Evolutionary Biology, Harvard University, Cambridge, Massachusetts, USA
| | - Christine Austin
- Department of Environmental Medicine and Public Health, Icahn School of Medicine at Mount Sinai, New York, New York, USA
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Stifler CA, Jakes JE, North JD, Green DR, Weaver JC, Gilbert PUPA. Crystal misorientation correlates with hardness in tooth enamels. Acta Biomater 2021; 120:124-134. [PMID: 32711081 DOI: 10.1016/j.actbio.2020.07.037] [Citation(s) in RCA: 18] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/11/2020] [Revised: 07/14/2020] [Accepted: 07/17/2020] [Indexed: 01/31/2023]
Abstract
The multi-scale hierarchical structure of tooth enamel enables it to withstand a lifetime of damage without catastrophic failure. While many previous studies have investigated structure-function relationships in enamel, the effects of crystal misorientation on mechanical performance have not been assessed. To address this issue, in the present study, we review previously published polarization-dependent imaging contrast (PIC) maps of mouse and human enamel, and parrotfish enameloid, in which crystal orientations were measured and displayed in every 60-nm-pixel. By combining those previous results with the PIC maps of sheep enamel presented here we discovered that, in all enamel(oid)s, adjacent crystals are slightly misoriented, with misorientation angles in the 0°-30° range, and mean 2°-8°. Within this limited range, misorientation is positively correlated with literature hardness values, demonstrating an important structure-property relation, not previously identified. At greater misorientation angles 8°30°, this correlation is expected to reverse direction, but data from different non-enamel systems, with more diverse crystal misorientations, are required to determine if and where this occurs. STATEMENT OF SIGNIFICANCE: We identify a structure-function relationship in tooth enamels from different species: crystal misorientation correlates with hardness, contributing to the remarkable mechanical properties of enamel in diverse animals.
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Affiliation(s)
- Cayla A Stifler
- Department of Physics, University of Wisconsin, Madison, WI 53706, United States
| | - Joseph E Jakes
- Forest Biopolymers Science and Engineering, USDA Forest Service, Forest Products Laboratory, Madison, WI 53726, United States
| | - Jamie D North
- Department of Chemistry, Carleton College, Northfield, MN 55057, United States
| | - Daniel R Green
- Department of Human Evolutionary Biology, Harvard University, Cambridge, MA 02138, United States
| | - James C Weaver
- Wyss Institute for Biologically Inspired Engineering, Harvard University, Cambridge, MA 02138, United States
| | - Pupa U P A Gilbert
- Department of Physics, University of Wisconsin, Madison, WI 53706, United States; Departments of Chemistry, Geoscience, Materials Science, University of Wisconsin, Madison, WI 53706, United States.
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Kierdorf H, Witzel C, Bocaege E, Richter T, Kierdorf U. Assessment of physiological disturbances during pre- and early postnatal development based on microscopic analysis of human deciduous teeth from the Late Epipaleolithic site of Shubayqa 1 (Jordan). AMERICAN JOURNAL OF PHYSICAL ANTHROPOLOGY 2020; 174:20-34. [PMID: 33017861 DOI: 10.1002/ajpa.24156] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/19/2020] [Revised: 09/12/2020] [Accepted: 09/19/2020] [Indexed: 01/27/2023]
Abstract
OBJECTIVES To study pre- and early postnatal tooth formation and to analyze the effects of physiological disturbances on enamel and dentin formation in deciduous teeth of infants from the Late Epipaleolithic (Natufian) site Shubayqa 1. MATERIALS AND METHODS Ten deciduous teeth from six infants (ages at death between 21 and 239 days) were analyzed by light and scanning electron microscopy. RESULTS Marked prism cross-striations and an abnormal wavy course of the prisms were recorded in pre- and postnatal enamel of all analyzed teeth. Single or multiple accentuated incremental lines were observed in prenatal enamel of nine teeth and in postnatal enamel of eight teeth. Accentuated Andresen lines and broader zones exhibiting an enhanced calcospheritic pattern were recorded in the pre- and postnatally formed dentin of nine teeth. DISCUSSION The structural abnormalities in the pre- and postnatally formed enamel of the infants are considered indicative of chronic stress that negatively affected the activity of secretory ameloblasts. The structural aberrations in pre- and postnatal dentin denote that odontoblasts were also affected by this stress. The presence of single or multiple accentuated incremental lines in pre- and postnatal enamel is interpreted as reflecting (short-term) impacts of higher intensity superimposed on the chronic stress. Our findings suggest compromised maternal health affecting the late fetus and compromised health in newborns. Although limited by the small number of analyzed individuals, the present study contributes to the knowledge of maternal and early infant health conditions in Late Epipaleolithic populations.
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Affiliation(s)
- Horst Kierdorf
- Department of Biology, University of Hildesheim, Hildesheim, Germany
| | - Carsten Witzel
- Department of Biology, University of Hildesheim, Hildesheim, Germany
| | - Emmy Bocaege
- School of Anthropology and Conservation, University of Kent, Canterbury, UK
| | - Tobias Richter
- Department of Cross-cultural and Regional Studies, University of Copenhagen, Copenhagen, Denmark
| | - Uwe Kierdorf
- Department of Biology, University of Hildesheim, Hildesheim, Germany
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11
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Papakyrikos AM, Arora M, Austin C, Boughner JC, Capellini TD, Dingwall HL, Greba Q, Howland JG, Kato A, Wang X, Smith TM. Biological clocks and incremental growth line formation in dentine. J Anat 2020; 237:367-378. [PMID: 32266720 PMCID: PMC7369199 DOI: 10.1111/joa.13198] [Citation(s) in RCA: 17] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/06/2020] [Revised: 03/12/2020] [Accepted: 03/16/2020] [Indexed: 01/01/2023] Open
Abstract
Dentine- and enamel-forming cells secrete matrix in consistent rhythmic phases, resulting in the formation of successive microscopic growth lines inside tooth crowns and roots. Experimental studies of various mammals have proven that these lines are laid down in subdaily, daily (circadian), and multidaily rhythms, but it is less clear how these rhythms are initiated and maintained. In 2001, researchers reported that lesioning the so-called master biological clock, the suprachiasmatic nucleus (SCN), halted daily line formation in rat dentine, whereas subdaily lines persisted. More recently, a key clock gene (Bmal1) expressed in the SCN in a circadian manner was also found to be active in dentine- and enamel- secretory cells. To probe these potential neurological and local mechanisms for the production of rhythmic lines in teeth, we reexamined the role of the SCN in growth line formation in Wistar rats and investigated the presence of daily lines in Bmal1 knockout mice (Bmal1-/- ). In contrast to the results of the 2001 study, we found that both daily and subdaily growth lines persisted in rat dentine after complete or partial SCN lesion in the majority of individuals. In mice, after transfer into constant darkness, daily rhythms continued to manifest as incremental lines in the dentine of each Bmal1 genotype (wild-type, Bmal+/- , and Bmal1-/- ). These results affirm that the manifestation of biological rhythms in teeth is a robust phenomenon, imply a more autonomous role of local biological clocks in tooth growth than previously suggested, and underscore the need further to elucidate tissue-specific circadian biology and its role in incremental line formation. Investigations of this nature will strengthen an invaluable system for determining growth rates and calendar ages from mammalian hard tissues, as well as documenting the early lives of fossil hominins and other primates.
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Affiliation(s)
- Amanda M. Papakyrikos
- Department of AnthropologyWellesley CollegeWellesleyMAUSA
- Department of Developmental BiologyStanford University School of MedicineStanfordCAUSA
| | - Manish Arora
- Department of Environmental Medicine and Public HealthIcahn School of Medicine at Mount SinaiNew YorkNYUSA
| | - Christine Austin
- Department of Environmental Medicine and Public HealthIcahn School of Medicine at Mount SinaiNew YorkNYUSA
| | - Julia C. Boughner
- Department of Anatomy, Physiology and PharmacologyCollege of MedicineUniversity of SaskatchewanSaskatoonSKCanada
| | | | | | - Quentin Greba
- Department of Anatomy, Physiology and PharmacologyCollege of MedicineUniversity of SaskatchewanSaskatoonSKCanada
| | - John G. Howland
- Department of Anatomy, Physiology and PharmacologyCollege of MedicineUniversity of SaskatchewanSaskatoonSKCanada
| | - Akiko Kato
- Department of Human Evolutionary BiologyHarvard UniversityCambridgeMAUSA
- Department of Oral AnatomySchool of DentistryAichi Gakuin UniversityNagoyaJapan
| | - Xiu‐Ping Wang
- Department of Developmental BiologyHarvard School of Dental MedicineBostonMAUSA
| | - Tanya M. Smith
- Department of Human Evolutionary BiologyHarvard UniversityCambridgeMAUSA
- Australian Research Centre for Human EvolutionGriffith UniversityNathanQldAustralia
- Griffith Centre for Social and Cultural ResearchGriffith UniversityNathanQldAustralia
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12
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Becker M, Witzel C, Kierdorf U, Frölich K, Kierdorf H. Ontogenetic changes of tissue compartmentalization and bone type distribution in the humerus of Soay sheep. J Anat 2020; 237:334-354. [PMID: 32255514 DOI: 10.1111/joa.13194] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/20/2019] [Revised: 02/09/2020] [Accepted: 03/09/2020] [Indexed: 12/24/2022] Open
Abstract
We studied ontogenetic changes of histomorphological features and bone type distribution in the humeral midshaft region of Soay sheep from three postnatal age classes (13, 25, and 33 months). Our study demonstrated a marked change of bone type distribution in the humeri with age. In the cortical midshaft region of 13-month-old individuals, periosteal fibrolamellar bone was the dominating bone type. This indicates a rapid bone growth during the first year of life, which was only interrupted by a seasonal growth arrest in the animals' first winter. In individuals from the two older age classes, periosteal lamellar-zonal bone and intermediate fibrolamellar bone had been formed at the periosteal surface, and endosteal lamellar-zonal bone at the endosteal surface. These bone types are indicative of a reduced bone growth rate. A marked reduction in radial growth was already recorded in the 25-month-old individuals. Distribution and extent of secondary bone showed a marked bilateral symmetry in the humeri of individual sheep. The presence of secondary bone was largely restricted to the anterior (cranial) and the medial cortical areas. This characteristic distribution of remodeling activity within the humeral cortex of sheep is consistent with the view that remodeling activity is largely caused by compressive stress. Our study further demonstrated the presence of a considerable cortical drift in the sheep humeri over the study period, with endosteal resorption occurring predominantly in the posterior (caudal) quadrant and formation of a prominent endosteal lamellar pocket in the anterior (cranial) and medial cortical quadrants.
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Affiliation(s)
- Margarethe Becker
- Department of Biology, University of Hildesheim, Hildesheim, Germany
| | - Carsten Witzel
- Department of Biology, University of Hildesheim, Hildesheim, Germany
| | - Uwe Kierdorf
- Department of Biology, University of Hildesheim, Hildesheim, Germany
| | | | - Horst Kierdorf
- Department of Biology, University of Hildesheim, Hildesheim, Germany
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Davis KA, Mountain RV, Pickett OR, Den Besten PK, Bidlack FB, Dunn EC. Teeth as Potential New Tools to Measure Early-Life Adversity and Subsequent Mental Health Risk: An Interdisciplinary Review and Conceptual Model. Biol Psychiatry 2020; 87:502-513. [PMID: 31858984 PMCID: PMC7822497 DOI: 10.1016/j.biopsych.2019.09.030] [Citation(s) in RCA: 25] [Impact Index Per Article: 6.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 04/10/2019] [Revised: 09/04/2019] [Accepted: 09/11/2019] [Indexed: 12/18/2022]
Abstract
Early-life adversity affects nearly half of all youths in the United States and is a known risk factor for psychiatric disorders across the life course. One strategy to prevent mental illness may be to target interventions toward children who are exposed to adversity, particularly during sensitive periods when these adversities may have even more enduring effects. However, a major obstacle impeding progress in this area is the lack of tools to reliably and validly measure the existence and timing of early-life adversity. In this review, we summarize empirical work across dentistry, anthropology, and archaeology on human tooth development and discuss how teeth preserve a time-resolved record of our life experiences. Specifically, we articulate how teeth have been examined in these fields as biological fossils in which the history of an individual's early-life experiences is permanently imprinted; this area of research is related to, but distinct from, studies of oral health. We then integrate these insights with knowledge about the role of psychosocial adversity in shaping psychopathology risk to present a working conceptual model, which proposes that teeth may be an understudied yet suggestive new tool to identify individuals at risk for mental health problems following early-life psychosocial stress exposure. We end by presenting a research agenda and discussion of future directions for rigorously testing this possibility and with a call to action for interdisciplinary research to meet the urgent need for new biomarkers of adversity and psychiatric outcomes.
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Siebke I, Moghaddam N, Cunningham CA, Witzel C, Lösch S. Those who died very young-Inferences from δ 15 N and δ 13 C in bone collagen and the absence of a neonatal line in enamel related to the possible onset of breastfeeding. AMERICAN JOURNAL OF PHYSICAL ANTHROPOLOGY 2019; 169:664-677. [PMID: 31050814 DOI: 10.1002/ajpa.23847] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/01/2018] [Revised: 04/11/2019] [Accepted: 04/16/2019] [Indexed: 11/07/2022]
Abstract
OBJECTIVES Stable isotope analysis has often been used in neonatal remains from archeological contexts to investigate the presence of a signal of breastfeeding and weaning in past populations. Tooth histology on the other hand might be used as an indicator of birth survival. This pilot study aimed to investigate the feasibility of using stable nitrogen (δ15 N) and carbon (δ13 C) isotope values from neonatal bone collagen to elucidate if values deviating from the adult female average could indicate breastfeeding and co-occur with the presence of a neonatal line (NNL). The combination of these independent indicators might be useful in clarifying the fate of individuals who died around birth. MATERIALS AND METHODS Bone collagen from 21 archeological human and animal specimens was extracted and analyzed via mass-spectrometry for δ15 N and δ13 C. A verification of the stable isotope results was undertaken using tooth histology on three individuals who were investigated for the presence of a NNL as an indicator of live birth and short survival. RESULTS The biological age of the human samples varied between 8.5 lunar months (Lm) and 2 postnatal months (Pm) of age. All except one individual exhibited elevated δ15 N values compared to the female average. The histological analyses revealed no NNL for this and two further individuals (n = 3). DISCUSSION The results indicate that elevated nitrogen values of very young infants relative to a female average in archeological contexts are not necessarily associated with a breastfeeding onset signal, and therefore cannot be used exclusively as a proxy of birth survival. The elevation might be possible due to various reasons; one could be nutritional, in particular maternal stress during pregnancy or a metabolic disorder of mother and/or her child. In those cases, the evaluation of a NNL might reveal a false breastfeeding signal as seen for two individuals in our sample who have elevated nitrogen values despite the fact no NNL could be observed. Overall, our data support the growing awareness that bone collagen δ15 N values of neonates/infants should not be used as a proxy for breastfeeding or birth survival on its own.
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Affiliation(s)
- Inga Siebke
- Department of Physical Anthropology, Institute of Forensic Medicine, University of Bern, Bern, Switzerland.,Centre for Anatomy and Human Identification, University of Dundee, Dundee, Scotland
| | - Negahnaz Moghaddam
- Department of Physical Anthropology, Institute of Forensic Medicine, University of Bern, Bern, Switzerland.,Unit of Forensic Imaging and Anthropology, University Center of Legal Medicine, University Hospitals Lausanne-Geneva, Lausanne, Switzerland
| | - Craig A Cunningham
- Centre for Anatomy and Human Identification, University of Dundee, Dundee, Scotland
| | - Carsten Witzel
- Institute of Biology and Chemistry, University of Hildesheim, Hildesheim, Germany
| | - Sandra Lösch
- Department of Physical Anthropology, Institute of Forensic Medicine, University of Bern, Bern, Switzerland
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15
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Kierdorf H, Breuer F, Witzel C, Kierdorf U. Pig enamel revisited – Incremental markings in enamel of wild boars and domestic pigs. J Struct Biol 2019; 205:48-59. [DOI: 10.1016/j.jsb.2018.11.009] [Citation(s) in RCA: 11] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/10/2018] [Revised: 11/19/2018] [Accepted: 11/21/2018] [Indexed: 10/27/2022]
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Witzel C, Kierdorf U, Frölich K, Kierdorf H. The pay-off of hypsodonty - timing and dynamics of crown growth and wear in molars of Soay sheep. BMC Evol Biol 2018; 18:207. [PMID: 30594146 PMCID: PMC6310973 DOI: 10.1186/s12862-018-1332-9] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/05/2018] [Accepted: 12/14/2018] [Indexed: 01/25/2023] Open
Abstract
Background Several lineages of herbivorous mammals have evolved hypsodont cheek teeth to increase the functional lifespan of their dentition. While the selective drivers of this trend and the developmental processes involved have been studied in greater detail, thus far no quantitative information is available on the relationship between additional investment into tooth growth and the resulting extension of the functional period of these teeth. To achieve this, we performed a detailed analysis of molar crown growth in known-age Soay sheep repeatedly injected with different fluorochromes. Results Our study revealed that in sheep molars especially the formation of the crown base portion is prolonged in comparison with other herbivorous artiodactyl species. Our results demonstrate that growth of the crown base accounted for more than half of the total crown formation time (CFT) of the anterior lobes of the first (approx. 220 days of total CFT of 300 days), second (approx. 260 of 460 days) and third (approx. 300 of at least 520 days) molars, and that the formation of this crown portion occurred largely after the teeth had already reached functional occlusion. By combining data on wear-related changes in crown morphology from the literature with the reconstructed additional investment into the crown base portion, it was possible to relate this additional investment to a prolongation of the functional periods of the molars ranging from 4 years in the M1 to 6 years in the M3. Conclusions Our results allow to establish a quantitative link between an additional investment into molar crown growth of sheep and the extension of the functional period of these teeth. The reported findings enable an assessment of the adaptive value, in terms of increased longevity, of an additional investment into crown elongation in a mammalian herbivore.
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Affiliation(s)
- Carsten Witzel
- Department of Biology, University of Hildesheim, Universitätsplatz 1, 31141, Hildesheim, Germany.
| | - Uwe Kierdorf
- Department of Biology, University of Hildesheim, Universitätsplatz 1, 31141, Hildesheim, Germany
| | - Kai Frölich
- Department of Biology, University of Hildesheim, Universitätsplatz 1, 31141, Hildesheim, Germany.,Tierpark Arche Warder e.V, Langwedeler Weg 11, 24646, Warder, Germany
| | - Horst Kierdorf
- Department of Biology, University of Hildesheim, Universitätsplatz 1, 31141, Hildesheim, Germany
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Geiger M, Marron S, West AR, Asher RJ. Influences of Domestication and Island Evolution on Dental Growth in Sheep. J MAMM EVOL 2018. [DOI: 10.1007/s10914-018-9452-y] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/28/2022]
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18
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O'Meara RN, Dirks W, Martinelli AG. Enamel formation and growth in non-mammalian cynodonts. ROYAL SOCIETY OPEN SCIENCE 2018; 5:172293. [PMID: 29892415 PMCID: PMC5990740 DOI: 10.1098/rsos.172293] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/20/2017] [Accepted: 04/13/2018] [Indexed: 06/01/2023]
Abstract
The early evolution of mammals is associated with the linked evolutionary origin of diphyodont tooth replacement, rapid juvenile growth and determinate adult growth. However, specific relationships among these characters during non-mammalian cynodont evolution require further exploration. Here, polarized light microscopy revealed incremental lines, resembling daily laminations of extant mammals, in histological sections of enamel in eight non-mammalian cynodont species. In the more basal non-probainognathian group, enamel extends extremely rapidly from cusp to cervix. By contrast, the enamel of mammaliamorphs is gradually accreted, with slow rates of crown extension, more typical of the majority of non-hypsodont crown mammals. These results are consistent with the reduction in dental replacement rate across the non-mammalian cynodont lineage, with greater rates of crown extension required in most non-probainognathians, and slower crown extension rates permitted in mammaliamorphs, which have reduced patterns of dental replacement in comparison with many non-probainognathians. The evolution of mammal-like growth patterns, with faster juvenile growth and more abruptly terminating adult growth, is linked with this reduction in dental replacement rates and may provide an additional explanation for the observed pattern in enamel growth rates. It is possible that the reduction in enamel extension rates in mammaliamorphs reflects an underlying reduction in skeletal growth rates at the time of postcanine formation, due to a more abruptly terminating pattern of adult growth in these more mammal-like, crownward species.
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Affiliation(s)
- Rachel N. O'Meara
- The University Museum of Zoology, Downing Street, Cambridge CB2 3EJ, UK
| | - Wendy Dirks
- Department of Anthropology, Durham University, Dawson Building, South Road, Durham DH1 3LE, UK
| | - Agustín G. Martinelli
- Departamento de Geociências, Universidade Federal do Rio Grande do Sul, Ave. Bento Gonçalves 9500, 91540-000 Porto Alegre, Rio Grande do Sul, Brazil
- Sección Paleontología de Vertebrados, Museo Argentino de Ciencias Naturales ‘Bernardino Rivadavia’, Av. Ángel Gallardo 470, Buenos Aires C1405DJR, Argentina
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Lyman RL. Dental enamel hypoplasias in Holocene bighorn sheep ( Oviscanadensis) in eastern Washington state, USA. CAN J ZOOL 2018. [DOI: 10.1139/cjz-2017-0230] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
Abstract
Dental enamel hypoplasias have been documented in extant and fossil mammal species and attributed to several kinds of physiological stress. They have not previously been reported among bighorn sheep (Ovis canadensis Shaw, 1804). Forty-six (36.8%) of 125 mandibular molars (m1, m2, m3) of bighorn recovered from disturbed Holocene archaeological deposits in eastern Washington state display several kinds of hypoplasias. The exact ontogenetic age of the individual animals when hypoplasias formed cannot be determined. The majority of the hypoplasias occur near the root–enamel junction of the m3, suggesting that most individuals were young adults when the defect formed. Physiological stress associated with reproductive costs, winter nutritional deficits, or both seems likely.
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Affiliation(s)
- R. Lee Lyman
- Department of Anthropology, 112 Swallow Hall, University of Missouri, Columbia, MO 65211, USA
- Department of Anthropology, 112 Swallow Hall, University of Missouri, Columbia, MO 65211, USA
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20
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Hogg R. Permanent Record: The Use of Dental and Bone Microstructure to Assess Life History Evolution and Ecology. VERTEBRATE PALEOBIOLOGY AND PALEOANTHROPOLOGY 2018. [DOI: 10.1007/978-3-319-94265-0_6] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/14/2022]
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21
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Kahle P, Witzel C, Kierdorf U, Frölich K, Kierdorf H. Mineral Apposition Rates in Coronal Dentine of Mandibular First Molars in Soay Sheep: Results of a Fluorochrome Labeling Study. Anat Rec (Hoboken) 2017; 301:902-912. [PMID: 29244244 DOI: 10.1002/ar.23753] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/07/2017] [Revised: 08/15/2017] [Accepted: 08/25/2017] [Indexed: 01/02/2023]
Abstract
We studied the spatio-temporal variation of mineral apposition rate (MAR) in postnatally formed coronal dentine of mandibular first molars from Soay sheep repeatedly injected with different fluorochromes. MAR declined along the cuspal to cervical crown axis, and from early to late formed dentine, that is, from the dentine at the enamel-dentine-junction (EDJ) to the dentine adjacent to the dentine-pulp-interface (DPI). Highest mean MARs (about 21 µm/day) were recorded in cuspal dentine formed in the period of 28-42 days after birth. Lowest values (<2 µm/day) were recorded in late-formed (secondary) dentine close to the DPI. The high MARs recorded in the dentine of the cuspal crown portions enable the formation of a large tooth crown within a relatively short period of less than one year. The established MARs in the dentine of the different crown portions of sheep molars will allow a precise determination of the timing of stress events affecting dentine formation. They are also helpful for devising sampling protocols in studies of trace element or stable isotope distributions in sheep dentine aimed at assessing temporal variation of incorporation into forming dentine. Such data are useful in a variety of contexts, including, for example, the exposure to pollutants and the reconstruction of husbandry practices or feeding regimes. Anat Rec, 301:902-912, 2018. © 2017 Wiley Periodicals, Inc.
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Affiliation(s)
- Patricia Kahle
- Department of Biology, University of Hildesheim, Universitätsplatz 1, Hildesheim, 31141, Germany
| | - Carsten Witzel
- Department of Biology, University of Hildesheim, Universitätsplatz 1, Hildesheim, 31141, Germany
| | - Uwe Kierdorf
- Department of Biology, University of Hildesheim, Universitätsplatz 1, Hildesheim, 31141, Germany
| | - Kai Frölich
- Tierpark Arche Warder e.V, Langwedeler Weg 11, Warder, 24646, Germany
| | - Horst Kierdorf
- Department of Biology, University of Hildesheim, Universitätsplatz 1, Hildesheim, 31141, Germany
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22
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Nacarino-Meneses C, Jordana X, Orlandi-Oliveras G, Köhler M. Reconstructing molar growth from enamel histology in extant and extinct Equus. Sci Rep 2017; 7:15965. [PMID: 29162890 PMCID: PMC5698294 DOI: 10.1038/s41598-017-16227-2] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/12/2017] [Accepted: 11/09/2017] [Indexed: 11/26/2022] Open
Abstract
The way teeth grow is recorded in dental enamel as incremental marks. Detailed analysis of tooth growth is known to provide valuable insights into the growth and the pace of life of vertebrates. Here, we study the growth pattern of the first lower molar in several extant and extinct species of Equus and explore its relationship with life history events. Our histological analysis shows that enamel extends beyond the molar’s cervix in these mammals. We identified three different crown developmental stages (CDS) in the first lower molars of equids characterised by different growth rates and likely to be related to structural and ontogenetic modifications of the tooth. Enamel extension rate, which ranges from ≈400 μm/d at the beginning of crown development to rates of ≈30 μm/d near the root, and daily secretion rate (≈17 μm/d) have been shown to be very conservative within the genus. From our results, we also inferred data of molar wear rate for these equids that suggest higher wear rates at early ontogenetic stages (13 mm/y) than commonly assumed. The results obtained here provide a basis for future studies of equid dentition in different scientific areas, involving isotope, demographic and dietary studies.
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Affiliation(s)
- Carmen Nacarino-Meneses
- Institut Català de Paleontologia Miquel Crusafont (ICP), Campus de la Universitat Autònoma de Barcelona, 08193 Bellaterra, Barcelona, Spain.
| | - Xavier Jordana
- Unitat d'Antropologia Biològica, BABVE department, Universitat Autònoma de Barcelona (UAB), 08193 Bellaterra, Barcelona, Spain
| | - Guillem Orlandi-Oliveras
- Institut Català de Paleontologia Miquel Crusafont (ICP), Campus de la Universitat Autònoma de Barcelona, 08193 Bellaterra, Barcelona, Spain
| | - Meike Köhler
- Institut Català de Paleontologia Miquel Crusafont (ICP), Campus de la Universitat Autònoma de Barcelona, 08193 Bellaterra, Barcelona, Spain.,ICREA, Pg. Lluís Companys 23, 08010, Barcelona, Spain
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Green DR, Green GM, Colman AS, Bidlack FB, Tafforeau P, Smith TM. Synchrotron imaging and Markov Chain Monte Carlo reveal tooth mineralization patterns. PLoS One 2017; 12:e0186391. [PMID: 29049333 PMCID: PMC5648163 DOI: 10.1371/journal.pone.0186391] [Citation(s) in RCA: 18] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/03/2017] [Accepted: 09/29/2017] [Indexed: 11/29/2022] Open
Abstract
The progressive character of tooth formation records aspects of mammalian life history, diet, seasonal behavior and climate. Tooth mineralization occurs in two stages: secretion and maturation, which overlap to some degree. Despite decades of study, the spatial and temporal pattern of elemental incorporation during enamel mineralization remains poorly characterized. Here we use synchrotron X-ray microtomography and Markov Chain Monte Carlo sampling to estimate mineralization patterns from an ontogenetic series of sheep molars (n = 45 M1s, 18 M2s). We adopt a Bayesian approach that posits a general pattern of maturation estimated from individual- and population-level mineral density variation over time. This approach converts static images of mineral density into a dynamic model of mineralization, and demonstrates that enamel secretion and maturation waves advance at nonlinear rates with distinct geometries. While enamel secretion is ordered, maturation geometry varies within a population and appears to be driven by diffusive processes. Our model yields concrete expectations for the integration of physiological and environmental signals, which is of particular significance for paleoseasonality research. This study also provides an avenue for characterizing mineralization patterns in other taxa. Our synchrotron imaging data and model are available for application to multiple disciplines, including health, material science, and paleontological research.
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Affiliation(s)
- Daniel R. Green
- Department of Human Evolutionary Biology, Harvard University, Cambridge, Massachusetts, United States of America
- Forsyth Institute, Cambridge, Massachusetts, United States of America
- * E-mail:
| | - Gregory M. Green
- Physics Department, Stanford University, Palo Alto, California, United States of America
- Kavli Institute for Particle Physics and Cosmology, Stanford University, Palo Alto, California, United States of America
| | - Albert S. Colman
- Department of the Geophysical Sciences, University of Chicago, Chicago, Illinois, United States of America
| | | | - Paul Tafforeau
- European Synchrotron Radiation Facility, Grenoble, France
| | - Tanya M. Smith
- Department of Human Evolutionary Biology, Harvard University, Cambridge, Massachusetts, United States of America
- Australian Research Center for Human Evolution, Griffith University, Brisbane, Australia
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Exceptionally prolonged tooth formation in elasmosaurid plesiosaurians. PLoS One 2017; 12:e0172759. [PMID: 28241059 PMCID: PMC5328283 DOI: 10.1371/journal.pone.0172759] [Citation(s) in RCA: 16] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/24/2015] [Accepted: 02/09/2017] [Indexed: 11/19/2022] Open
Abstract
Elasmosaurid plesiosaurians were globally prolific marine reptiles that dominated the Mesozoic seas for over 70 million years. Their iconic body-plan incorporated an exceedingly long neck and small skull equipped with prominent intermeshing ‘fangs’. How this bizarre dental apparatus was employed in feeding is uncertain, but fossilized gut contents indicate a diverse diet of small pelagic vertebrates, cephalopods and epifaunal benthos. Here we report the first plesiosaurian tooth formation rates as a mechanism for servicing the functional dentition. Multiple dentine thin sections were taken through isolated elasmosaurid teeth from the Upper Cretaceous of Sweden. These specimens revealed an average of 950 daily incremental lines of von Ebner, and infer a remarkably protracted tooth formation cycle of about 2–3 years–other polyphyodont amniotes normally take ~1–2 years to form their teeth. Such delayed odontogenesis might reflect differences in crown length and function within an originally uneven tooth array. Indeed, slower replacement periodicity has been found to distinguish larger caniniform teeth in macrophagous pliosaurid plesiosaurians. However, the archetypal sauropterygian dental replacement system likely also imposed constraints via segregation of the developing tooth germs within discrete bony crypts; these partly resorbed to allow maturation of the replacement teeth within the primary alveoli after displacement of the functional crowns. Prolonged dental formation has otherwise been linked to tooth robustness and adaption for vigorous food processing. Conversely, elasmosaurids possessed narrow crowns with an elongate profile that denotes structural fragility. Their apparent predilection for easily subdued prey could thus have minimized this potential for damage, and was perhaps coupled with selective feeding strategies that ecologically optimized elasmosaurids towards more delicate middle trophic level aquatic predation.
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Frölich K, Jandowsky A. [The importance of conservation of rare domestic animal breeds using the example of Arc Warder]. Tierarztl Prax Ausg G Grosstiere Nutztiere 2017; 45:33-41. [PMID: 28070591 DOI: 10.15653/tpg-160777] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/08/2016] [Accepted: 10/17/2017] [Indexed: 11/22/2022]
Abstract
The domestic animals descend from various wild ancestors. Thus, for example, of the wolf, the dog (15 000 BC), of the Bezoar goat the goat (10 000 BC), of the Asian mouflon the sheep (10 000 BC), of the wild boar the pig (8000 BC) and of the aurochs the cattle (7000 BC). Domestication has dramatically changed our culture and led to a great diversity of animal breeds. This is a unique cultural and historical treasure, which we have to preserve for future generations. The zoological park Arc Warder is Europe's largest center for rare and endangered domestic animal breeds. Arc Warder is more than a zoo; it is a landscape park, a conservation venture for genetic resources and furthermore a research project. Five principles guide the conservation efforts of Arc Warder: 1. Conservation through preservation. The breeding program will improve the quality of the genetic reservoir of breeds. 2. Conservation through the establishment of satellite stations. These pastures outside the park allow to increase the gene pool and ensure the protection of breeds against epidemics. 3. Conservation through high level education. 4. Protection by networking with national and international institutions. 5. Protection through research. Arc Warder is actively involved in close scientific cooperation with various universities and other research institutions on a number of scientific projects concerning the biological characteristics of old breeds.
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Affiliation(s)
- Kai Frölich
- Prof. Dr. med. vet. habil. Dr. rer. nat. Kai Frölich, Tierpark Arche Warder, Zentrum für seltene Nutztierrassen e. V., Langwedeler Weg 11, 24646 Warder, E-Mail:
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Kierdorf U, Death C, Hufschmid J, Witzel C, Kierdorf H. Developmental and Post-Eruptive Defects in Molar Enamel of Free-Ranging Eastern Grey Kangaroos (Macropus giganteus) Exposed to High Environmental Levels of Fluoride. PLoS One 2016; 11:e0147427. [PMID: 26895178 PMCID: PMC4760926 DOI: 10.1371/journal.pone.0147427] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/13/2015] [Accepted: 01/04/2016] [Indexed: 11/18/2022] Open
Abstract
Dental fluorosis has recently been diagnosed in wild marsupials inhabiting a high-fluoride area in Victoria, Australia. Information on the histopathology of fluorotic marsupial enamel has thus far not been available. This study analyzed the developmental and post-eruptive defects in fluorotic molar enamel of eastern grey kangaroos (Macropus giganteus) from the same high-fluoride area using light microscopy and backscattered electron imaging in the scanning electron microscope. The fluorotic enamel exhibited a brownish to blackish discolouration due to post-eruptive infiltration of stains from the oral cavity and was less resistant to wear than normally mineralized enamel of kangaroos from low-fluoride areas. Developmental defects of enamel included enamel hypoplasia and a pronounced hypomineralization of the outer (sub-surface) enamel underneath a thin rim of well-mineralized surface enamel. While the hypoplastic defects denote a disturbance of ameloblast function during the secretory stage of amelogenesis, the hypomineralization is attributed to an impairment of enamel maturation. In addition to hypoplastic defects, the fluorotic molars also exhibited numerous post-eruptive enamel defects due to the flaking-off of portions of the outer, hypomineralized enamel layer during mastication. The macroscopic and histopathological lesions in fluorotic enamel of M. giganteus match those previously described for placental mammals. It is therefore concluded that there exist no principal differences in the pathogenic mechanisms of dental fluorosis between marsupial and placental mammals. The regular occurrence of hypomineralized, opaque outer enamel in the teeth of M. giganteus and other macropodids must be considered in the differential diagnosis of dental fluorosis in these species.
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Affiliation(s)
- Uwe Kierdorf
- Department of Biology, University of Hildesheim, Hildesheim, Germany
- * E-mail:
| | - Clare Death
- Faculty of Veterinary and Agricultural Sciences, The University of Melbourne, Werribee, Victoria, Australia
| | - Jasmin Hufschmid
- Faculty of Veterinary and Agricultural Sciences, The University of Melbourne, Werribee, Victoria, Australia
| | - Carsten Witzel
- Department of Biology, University of Hildesheim, Hildesheim, Germany
| | - Horst Kierdorf
- Department of Biology, University of Hildesheim, Hildesheim, Germany
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Jordana X, Marín-Moratalla N, Moncunill-Solé B, Köhler M. Ecological and life-history correlates of enamel growth in ruminants (Artiodactyla). Biol J Linn Soc Lond 2014. [DOI: 10.1111/bij.12264] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/30/2023]
Affiliation(s)
- Xavier Jordana
- Institut Català de Paleontologia Miquel Crusafont (ICP); Universitat Autònoma de Barcelona; 08193 Bellaterra Barcelona Spain
| | - Nekane Marín-Moratalla
- Institut Català de Paleontologia Miquel Crusafont (ICP); Universitat Autònoma de Barcelona; 08193 Bellaterra Barcelona Spain
| | - Blanca Moncunill-Solé
- Institut Català de Paleontologia Miquel Crusafont (ICP); Universitat Autònoma de Barcelona; 08193 Bellaterra Barcelona Spain
| | - Meike Köhler
- ICREA at Institut Català de Paleontologia Miquel Crusafont (ICP); Universitat Autònoma de Barcelona; 08193 Bellaterra Barcelona Spain
- Departament d'Ecologia; Facultat de Biologia; Universitat de Barcelona; Diagonal 645 E-08028 Barcelona Spain
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Kierdorf H, Breuer F, Richards A, Kierdorf U. Characterization of Enamel Incremental Markings and Crown Growth Parameters in Minipig Molars. Anat Rec (Hoboken) 2014; 297:1935-49. [DOI: 10.1002/ar.22951] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Revised: 04/09/2014] [Accepted: 04/11/2014] [Indexed: 11/12/2022]
Affiliation(s)
- Horst Kierdorf
- Department of Biology; University of Hildesheim; Germany
| | | | | | - Uwe Kierdorf
- Department of Biology; University of Hildesheim; Germany
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