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Please use this identifier to cite or link to this item: http://repository.iitr.ac.in/handle/123456789/6348
Title: Development and evolution of the unique cetacean dentition
Authors: Armfield B.A.
Zheng Z.
Bajpai, Sunil
Vinyard C.J.
Thewissen J.G.M.
Published in: PeerJ
Abstract: The evolutionary success of mammals is rooted in their high metabolic rate. A high metabolic rate is sustainable thanks to efficient food processing and that in turn is facilitated by precise occlusion of the teeth and the acquisition of rhythmic mastication. These major evolutionary innovations characterize most members of the ClassMammalia. Cetaceans are one of the few groups of mammals in which precise occlusion has been secondarily lost.Most toothed whales have an increased number of simple crowned teeth that are similar along the tooth row. Evolution toward these specializations began immediately after the time cetaceans transitioned from terrestrial-to-marine environments. The fossil record documents the critical aspects of occlusal evolution of cetaceans, and allows us to pinpoint the evolutionary timing of the macroevolutionary events leading to their unusual dental morphology among mammals. The developmental controls of tooth differentiation and tooth number have been studied in a few mammalian clades, but nothing is known about how these controls differ between cetaceans and mammals that retain functional occlusion. Here we show that pigs, a cetacean relative with regionalized tooth morphology and complex tooth crowns, retain the typical mammalian gene expression patterns that control early tooth differentiation, expressing Bmp4 in the rostral (mesial, anterior) domain of the jaw, and Fgf8 caudally (distal, posterior). By contrast, dolphins have lost these regional differences in dental morphology and the Bmp4 domain is extended into the caudal region of the developing jaw. We hypothesize that the functional constraints underlying mammalian occlusion have been released in cetaceans, facilitating changes in the genetic control of early dental development. Such major developmental changes drive morphological evolution and are correlated with major shifts in diet and food processing during cetacean evolution. © 2013 Armfield et al.
Citation: PeerJ (2013), 2013(1): -
URI: https://doi.org/10.7717/peerj.24
http://repository.iitr.ac.in/handle/123456789/6348
Issue Date: 2013
Keywords: Cetacea
Cetacean
Evo-devo
Paleontology
Teeth
ISSN: 21678359
Author Scopus IDs: 36166588200
8387598100
16214305000
6602603193
57205523229
Author Affiliations: Armfield, B.A., Department of Anatomy and Neurobiology, Northeast Ohio Medical University, Rootstown, OH, United States, Howard Hughes Medical Institute and Department of Molecular Genetics and Microbiology, University of Florida, Gainesville, FL, United States
Zheng, Z., Howard Hughes Medical Institute and Department of Molecular Genetics and Microbiology, University of Florida, Gainesville, FL, United States
Bajpai, S., Department of Earth Sciences, Indian Institute of Technology, Roorkee, India, Birbal Sahni Institute of Palaeobotany, Lucknow, UP, India
Vinyard, C.J., Department of Anatomy and Neurobiology, Northeast Ohio Medical University, Rootstown, OH, United States
Thewissen, J.G.M., Department of Anatomy and Neurobiology, Northeast Ohio Medical University, Rootstown, OH, United States
Corresponding Author: Armfield, B.A.; Department of Anatomy and Neurobiology, Northeast Ohio Medical University, Rootstown, OH, United States; email: Barmfield@ufl.edu
Appears in Collections:Journal Publications [ES]

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