4C, A SEA

In some seaweeds, an organized structure referred to as a cuticle has been described, although the formation of the plant cuticle is known to be a land plant feature. These cuticles share the same localization at the interface with the environment; however, their distinct biochemistry and habitat of the organisms (aquatic versus land life) imply differences in their physicochemical properties and biological functions.

Scientific literature in this area remains scarce, but clearly indicates an evolutionary convergence to form a cuticle with distinct molecular mechanisms. Genes associated with algal cuticle formation are currently investigated and biological roles of the cuticle are questioned to understand its independent emergence in seaweeds.

Specifically, the project aims to characterize the cuticle of the Irish moss (Chondrus crispus), a red seaweed that grows in Brittany and is a studied model at the Station Biologique de Roscoff. Notably, the cuticle offers a unique and remarkable blue structural coloration to this alga, due to a characteristic architecture that produces light interference.

An important accomplishment of this project consisted of the identification of the cuticle building blocks by chemical characterization. Surprisingly, structural similarities with animal molecules, rather than with plants, were revealed. Then, experiments were conducted to study interactions between the different components in order to understand their assembly. The results are available online:  https://www.biorxiv.org/content/10.64898/2026.01.12.698930v1