The variability in the structural and functional properties of coccolith base plates

Area of Science:

• Biomineralization
• Marine Biology
• Crystallography

Background:

• Coccoliths are intricate crystalline scales produced by unicellular algae.
• The organic base plate was hypothesized to direct oriented crystal nucleation via stereochemical interactions.
• Previous research suggested indirect interactions play a role in coccolith formation.

Purpose of the Study:

• To systematically investigate the structural and chemical properties of coccolith base plates across different species.
• To explore the relationship between base plate characteristics and coccolith properties.
• To understand the mechanisms underlying controlled biomineralization in coccoliths.

Main Methods:

• Development of tools to extract base plates from five different algal species.
• Utilized multiple imaging techniques to analyze base plates under native hydrated conditions.
• Cryo electron microscopy was employed to reveal native state organization.

Main Results:

• Base plates exhibit a wide range of properties across species, built upon a common rudimentary scaffold.
• No detectable structural or chemical motifs on base plates explain direct nucleation control.
• Observed similarities and differences in base plate architecture were documented.

Conclusions:

• The chemical microenvironment within the cell, not just stereochemical matching with the base plate, is crucial for controlled coccolith crystallization.
• Biological organic scaffolds and their surrounding chemical milieu cooperatively facilitate precise biomineralization.
• This study reframes the understanding of how algae achieve exquisite control over inorganic material formation.