Nature Reviews Genetics - Hourglass theory gets molecular approval. ... The genes whose expression follows the hourglass pattern are also most likely to be involved in core developmental processes.

Although the hourglass patterns are clear, answering why this pattern exists remains challenging. Complex multicellularity requires cell adhesion, cell communication and developmental programs.

Researchers at the Max Planck Institute for Biology, Germany, have discovered a conserved developmental pattern known as the hourglass model in brown algae, providing more evidence that the ...