A Functionally Conserved yet Dynamically Evolving Toolkit Underpinning Molluscan Biomineralization: Insights From...

Area of Science:

• Evolutionary biology
• Biomineralization
• Genomics

Background:

• Molluscan shell and radula are key innovations with diverse forms regulated by biomineralization networks.
• Conserved components and evolutionary processes of these networks are not fully understood.

Purpose of the Study:

• Investigate the evolution of biomineralization regulatory networks in mollusks.
• Integrate data from understudied lineages like Scaphopoda.
• Characterize the conserved and novel elements in shell and radula formation.

Main Methods:

• Performed the first comprehensive transcriptome analysis of Pictodentalium vernedei (Scaphopoda).
• Utilized comparative transcriptome and genome analyses.
• Identified and analyzed protein domains within molluscan secretomes.

Main Results:

• Identified a core repertoire of 26 essential protein domains in molluscan secretomes for biomineralization.
• These domains form a toolkit that has undergone independent expansion and recruitment.
• Found evidence of ancient gene co-option and de novo gene emergence driving evolutionary innovation.

Conclusions:

• The secretome plays a central role in molluscan biomineralization.
• A conserved set of protein domains provides a foundation for shell and radula diversification.
• Evolutionary processes involve both co-option of existing genes and creation of new ones.