University of Tsukuba researchers have made a groundbreaking discovery about shell formation in mollusks, particularly in limpets. Their latest study, published in the journal Development, sheds light on how shell-forming cells are determined during early development, challenging previous beliefs in the field of developmental biology.
Autonomous Specification of Shell-Forming Cells in Limpets
Traditionally, it was believed that shell-forming cells in mollusks developed through induction—communication and interaction with neighboring cell types like endoderm cells. However, the University of Tsukuba team has demonstrated that in limpets, these cells are specified autonomously, without the need for external signals from other cell lineages.
How the Study Was Conducted
The researchers focused on the gastropod species Nipponacmea fuscoviridis. Using advanced techniques such as blastomere isolation, single-cell transcriptomics, and gene expression analysis, they carefully traced the developmental fate of shell-forming cells.
Key findings from the study include:
- Early larval shell-forming cells can be divided into at least three distinct types, each characterized by unique gene expression profiles.
- When blastomeres destined to become shell-forming cells were isolated and cultured separately from other cells, they still followed their developmental path.
- This indicates that cell-to-cell interactions are not necessary for the initial specification of shell-forming cells in limpets, contradicting long-held assumptions.
Why This Discovery Matters
Understanding how shell-forming cells differentiate is crucial for explaining the diverse shell structures observed across mollusks, from clams (bivalves) to snails (gastropods). This new evidence of autonomous specification opens the door to a deeper exploration of mollusk evolution and could provide insights into how animal body plans diversified over millions of years.
The researchers aim to further explore the molecular mechanisms driving this autonomous development and investigate how these mechanisms evolved to contribute to the incredible variety of mollusk morphologies seen today.
Reference
- Supanat Phuangphong et al., Characterization of shell field populations in gastropods and their autonomous specification mechanism independent of inter-quartet interactions, Development (2025). DOI: 10.1242/dev.204538
Provided by: University of Tsukuba