Enamel evolution: Back in time by a molecular manipulation
Bibliographic record
Abstract
Biomineralization is one of the key processes during vertebrate evolution that incorporates calcium and phosphate ions into soft matrices in the form of hydroxyapatite. Occurrence of mineralized tissues have offered the basis for various adaptive phenotypes such as endoskeleton for locomotion (bone), body armor for protection and teeth (enamel, dentin) for predation. Enamel is unique among the mineralized tissues, as it is formed on specific network of enamel matrix proteins (EMPs) secreted by epithelial ameloblasts. The two key structural proteins of enamel, amelogenin (AMEL) and ameloblastin (AMBN), self‐assemble into higher‐ordered structures from monomeric intrinsically disordered subunits as does the type I collagen (COL1), the predominant matrix protein in bone and dentine. While COL1 undergoes self‐assembly via consecutive Gly‐X‐Y motif, the mechanism of self‐assembly of EMPs and their subsequent role in formation of organized layer of hydroxyapatite crystals remains poorly understood. We report here a novel evolutionary conserved self‐assembly motif common to the key structural enamel matrix proteins AMBN and AMEL. The presence of this motif is essential for self‐assembly of AMBN and AMEL into higher‐ordered structures. These structures are essential for proper enamel formation. Transgenic mice that were unable to produce supramolecular structures of AMBN due to point substitutions within the identified self‐assembly motif then produced severely affected enamel with simplified organization. Despite the normal cellular organization, EMPs secretion and Ca and P levels within the growing enamel of transgenic mouse, the affected enamel lacked organized prismatic structures and showed only radial organization without visible Hunter‐Schreger bands. Moreover, enamel of mutant mice contained an enormous portion of interprismatic matrix with hypomineralized, yet well recognizable, crystallites, while no formation of oriented crystallites was observed within the compromised prisms. This is the first in vivo evidence that the formation of supramolecular structures of enamel matrix proteins was essential for evolution of highly structured enamel in mammals.
Fetched live from OpenAlex and de-inverted. Abstracts are not stored in this database: the inverted indexes are 8.6 GB of the frame’s 9.3 GB of text, and the host has 13 GB free.
How this classification was reachedexpand
Full frame distilled prediction
Teacher imitationNot calibrated prevalence, not ground truth. Human validation pending. Learned from the 10,348 direct Codex labels and 10,348 direct Gemma labels. Candidate is the union of thresholded teacher heads; consensus is their intersection. These outputs are machine_predicted_unvalidated and are not human labels or direct frontier model labels.
Codex and Gemma teacher scores by category
| Category | Codex | Gemma |
|---|---|---|
| Metaresearch | 0.000 | 0.000 |
| Meta-epidemiology (narrow) | 0.001 | 0.000 |
| Meta-epidemiology (broad) | 0.001 | 0.000 |
| Bibliometrics | 0.000 | 0.000 |
| Science and technology studies | 0.000 | 0.000 |
| Scholarly communication | 0.000 | 0.000 |
| Open science | 0.000 | 0.000 |
| Research integrity | 0.000 | 0.000 |
| Insufficient payload (model declined to judge) | 0.004 | 0.021 |
Machine scores (provisional)
The two teacher heads of the student model, read on this work. A score orders the frame for review; it never asserts a category, and the validation status ships verbatim with every row.
Baseline scores from an immature model (maturity gate not passed, 7 training rounds). Scores rank; they never assert a category.
score_only:v0-immature-baseline · verbatim from the scoring run: score_only means the number may rank works, and no category label ships from itClassification
machine, unvalidatedMachine predicted; both teacher heads agree on what is shown here.
How this classification was reached, model by model and score by score, is at the end of the page under "How this classification was reached".