NF-kappaB and Snail1a coordinate the cell cycle with gastrulation

Area of Science:

• Developmental Biology
• Cell Cycle Regulation
• Molecular Mechanisms

Background:

• Cell cycle coordination is vital for embryonic development, but the underlying molecular mechanisms are not fully understood.
• Gastrulation involves complex cell movements essential for establishing the body plan and tissues.
• Understanding cell cycle's role in gastrulation is key to developmental biology.

Purpose of the Study:

• To investigate the molecular mechanisms linking cell cycle regulation to gastrulation cell movements in zebrafish.
• To elucidate how the cell cycle influences mesendodermal cell delamination during zebrafish gastrulation.

Main Methods:

• Developed a system to modulate the cell cycle in early zebrafish embryos by altering the geminin-Cdt1 balance.
• Assessed changes in apoptotic levels during gastrulation in response to cell cycle modulation.
• Investigated the correlation between cell cycle alterations, apoptotic levels, and the nuclear factor kappaB (NF-kappaB) pathway.

Main Results:

• Modulating the cell cycle in zebrafish embryos altered apoptotic levels during gastrulation.
• Apoptotic level changes correlated with the nuclear levels of the antiapoptotic factor NF-kappaB.
• NF-kappaB was found to bind to the Snail1a promoter, directly activating its transcription.
• Snail1a, a key regulator of cell delamination, was transcriptionally controlled by NF-kappaB in response to cell cycle changes.

Conclusions:

• The cell cycle coordinates mesendodermal cell delamination during gastrulation through the NF-kappaB-mediated transcriptional activation of Snail1a.
• This study reveals a molecular pathway where NF-kappaB and Snail1a integrate cell cycle signals with developmental processes like gastrulation.