The machanism of nuclear formation for calcium carbonate biomineralization: the analysis using a medaka mutant

点击翻译按钮获取中文摘要

Calcium carbonate biominerals participate in diverse physiological functions and have impacts on global carbon and calcium cycles (e.g. coral reef). However, little is known about how mineralization is initiated in organisms. The medaka mutant ha lacks a trigger for otolith (calcium carbonate ear stone) mineralization, and the causative gene was found to encode polyketide synthase (OlPKS), a multifunctional enzyme mainly found in bacteria, fungi and plant including calcified algae. Subsequent experiments demonstrate that the products of OlPKS act as nucleation facilitators in otolith mineralization. The generality of this novel PKS function is supported by the essential role of echiderm PKS in calcareous skeleton formation together with the presence of PKSs in a much wider range of animals from coral to vertebrates. The present study first links PKS to biomineralization and provides a genetic cue for biogeochemistry of carbon and calcium cycles.