Mechanical force alters morphogenetic movements and segmental gene expression patterns during Drosophila...

Area of Science:

• Developmental Biology
• Cell Biology
• Biophysics

Background:

• Cellular morphogenetic movements, nuclear morphology, and transcription are key to organism development.
• Intra/inter-cellular adhesion proteins influence nuclear shape.
• Nuclear 3D organization regulates transcription, but its link to morphogenetic movements is unclear.

Purpose of the Study:

• To investigate the coupling between cellular morphogenetic movements and nuclear function during development.
• To probe the impact of mechanical perturbations on nuclear morphology and gene expression.

Main Methods:

• Laser ablation for point perturbation of tissue.
• Magnetic tweezers for sheet perturbation and force application.
• Analysis of nuclear morphology and segmental gene expression (engrailed) in Drosophila embryos.

Main Results:

• Mechanical perturbations caused localized changes in nuclear morphology and cell movement.
• External forces induced global defects in germ-band extension/retraction, indicating long-range coupling.
• Force application altered non-muscle myosin-II distribution and segmental gene expression patterns.

Conclusions:

• Tight regulation exists between nuclear morphology, cell adhesion, and morphogenetic movement.
• Nuclear integrity is vital for cellular movement to establish gene expression programs.
• Mechanical forces significantly impact developmental patterning through physical coupling.