A team of researchers from Okayama University in Japan and the University of California, Riverside Bourns College of Engineering has discovered the genes that allow a marine mollusk — the gumboot chiton — to regrow teeth containing magnetite, a geologic material with the maximum hardness of any known biomaterial. The findings may lead to improvements in abrasion-resistant dental materials.
The mollusk uses specialized teeth made from the magnetic mineral magnetite to scrape algae off ocean rocks, and once teeth wear down a new set forms. Magnetite is deposited only in the cusp region.
After examining the teeth’s transcriptome, researchers found the 20 most abundant RNA transcripts in the developing teeth contain ferritin, a protein that stores and releases iron, while those in the mineralized teeth include proteins of mitochondria that may provide the energy required to transform the raw materials into magnetite. Investigators also identified 22 proteins on the fully mineralized cusp that included a new protein dubbed radular teeth matrix protein1, which may interact with substances on the teeth to produce iron oxide. The paper, “Integrated Transcriptomic and Proteomic Analyses of a Molecular Mechanism of Radular Teeth Biomineralization in Cryptochiton stelleri,” appears in Scientific Reports.
From Decisions in Dentistry. March 2019;5(3):8.