A "developmental hourglass" in fungi

Area of Science:

• Developmental Biology
• Evolutionary Biology
• Mycology

Background:

• The developmental hourglass model posits that intermediate developmental stages are evolutionarily conserved.
• Gene expression during these conserved stages is ancient and highly regulated in animals and plants.
• This model has not been previously investigated in fungi.

Purpose of the Study:

• To investigate the existence of a molecular developmental hourglass in the model fungus Coprinopsis cinerea.
• To compare developmental gene expression patterns across animals, plants, and fungi.
• To understand conserved eukaryotic strategies for evolutionary innovation.

Main Methods:

• Generated comprehensive transcriptomic data across the entire lifecycle of Coprinopsis cinerea.
• Analyzed gene expression patterns, transcriptome age index, and transcriptome divergence index.
• Compared gene expression profiles related to "information storage and processing," "metabolism," and "signal transduction mechanisms" across kingdoms.

Main Results:

• Observed a molecular hourglass phenomenon during the development of Coprinopsis cinerea.
• Identified the "young fruiting body" stage as expressing the oldest and most conserved transcriptome.
• Demonstrated conserved gene expression patterns across animals, plants, and fungi, with "information storage and processing" genes high at the waist stage and "metabolism" genes later, while "signal transduction" is underrepresented at the waist.

Conclusions:

• The developmental hourglass is conserved across animals, plants, and fungi, indicating a shared eukaryotic developmental strategy.
• This conserved hourglass mechanism facilitates the incorporation of evolutionary innovations.
• The findings reveal a fundamental principle of eukaryotic evolution and development.