Noncollagenous Nature of the Proteins of Shark Enamel

Levine, Philip T.; Glimcher, Melvin J.; Seyer, Jerome M.; Huddleston, James I.; Hein, John W.

doi:10.1126/science.154.3753.1192

Cited by 29 publications

(14 citation statements)

References 14 publications

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“…Noncollagenous proteins are believed to be present in the enameloid matrix (Everett and Miller, 1981;Goto, 1978b;Kobayashi, 1993;Levine et al, 1966). However, the details are still unknown.…”

Section: Tubular Vesicles Are the Major Component In The Enameloid Mamentioning

confidence: 97%

Mineralization patterns in elasmobranch fish

Sasagawa

2002

Microscopy Res & Technique

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This article reviews current findings on the organic matrix and the mineralization patterns in elasmobranchs, including an analysis of the role of the dental epithelial cells and the odontoblasts during odontogenesis. Our electron micrographs demonstrated that tubular vesicles limited by a unit membrane occupied the bulk of the elasmobranch enameloid matrix during the stage of enameloid matrix formation. It is likely that the tubular vesicles originated from the odontoblast processes. Two types of electron-dense fibrils, with cross-striations at intervals of approximately either 17 nm or 55 nm, respectively, were detected in the enameloid matrix. These data suggest that odontoblasts were strongly involved in enameloid matrix formation and in initial enameloid mineralization. Two types of odontoblasts, dark and light cells, were recognized during the stage of dentinogenesis. The light cells contained numerous mitochondria, intermediate filaments, and microtubules that extended their processes into the dentin. The dark cells possessed a well-developed Golgi apparatus and many cisternae in the rough endoplasmic reticulum, which suggests that the dark cells are involved in the formation of dentin. The inner dental epithelial (IDE) cells exhibited a well-developed Golgi apparatus, many mitochondria, cisternae of smooth endoplasmic reticulum, vesicles, vacuoles, and granules during the mineralization and maturation stages. During the stages of mineralization and early maturation, ACPase-positive granules were visible in the IDE cells and ALPase and Ca-ATPase activities were found at the lateral and proximal cell membrane of the IDE cells, suggesting that the IDE cells are involved in the removal of enameloid organic matrix and in the process of mineralization during later stages of enameloid formation. Our data indicate that elasmobranch enameloid is distinct from teleost enameloid, based on its organic content, on the mechanisms of its mineralization, and on the role of IDE cells concerning enameloid formation.

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Section: Tubular Vesicles Are the Major Component In The Enameloid Mamentioning

confidence: 97%

Mineralization patterns in elasmobranch fish

Sasagawa

2002

Microscopy Res & Technique

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“…Their methods of biochemical analysis differed in some im portant respects to ours ), and while they disagree with our designation of this organic m atrix as a collagen, they wholeheartedly agree with the only biologically im por ta n t point we m ade; i.e., th a t this shark enamel m atrix is ectoderm al in origin (Levine et al [1966]). …”

Section: The Co-participation Hypothesis A)mentioning

confidence: 97%

Comparative anatomy of vertebrate dermal bone and teeth

Moss¹

1968

Cells Tissues Organs

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“…The data presented corroborate evidence for enamel biogenesis provided by a number of studies in disparate vertebrate species that have suggested the anionic enamel proteins are expressed before amelogenins. Levine et al [33] showed that protein(s) of shark enameloid have an amino acid composition similar to that of enamelins, but do not contain amelogenins. Enamelins appear to be expressed prior to amelogenins in fetal bovine teeth [72].…”

Section: Classification Of Enamel Polypeptides According To Temporal mentioning

confidence: 99%