SpHnf6, a transcription factor that executes multiple functions in sea urchin embryogenesis

Area of Science:

• Developmental Biology
• Genetics
• Marine Biology

Background:

• The ONECUT family of transcription factors plays vital roles in development.
• Understanding gene regulatory networks is essential for deciphering developmental processes.

Purpose of the Study:

• To investigate the function of the Strongylocentrotus purpuratus hnf6 (Sphnf6) gene in sea urchin embryonic development.
• To elucidate the distinct roles of the Hnf6 transcription factor throughout embryogenesis.

Main Methods:

• Loss-of-function analysis to determine gene requirements.
• Gene expression analysis to identify regulated genes.
• Micromere transplantation experiments to assess signaling roles.

Main Results:

• Sphnf6 is required for the activation of PMC differentiation genes (sm50, pm27, msp130) and the mesodermal regulator gatac.
• Sphnf6 is essential for maintaining oral ectoderm specification and neurogenic ciliated band formation.
• Sphnf6 expression is triphasic, with roles in early development, post-gastrulation oral ectoderm, and the ciliated band.

Conclusions:

• The Hnf6 transcription factor has multiple, distinct roles in sea urchin development, impacting both mesodermal and ectodermal lineages.
• Sphnf6 is a critical regulator of gene activation and cell fate determination in early sea urchin embryogenesis.
• The findings highlight the complex regulatory roles of transcription factors in orchestrating developmental events.