Multicellular rosette formation during cell ingression in the avian primitive streak

Area of Science:

• Developmental biology
• Cell biology
• Embryology

Background:

• Cell movements are crucial for multicellular organism development.
• Gastrulation in amniotes involves cell ingression via the primitive streak, establishing embryonic axes.

Purpose of the Study:

• To investigate cytoskeletal architecture during amniote gastrulation.
• To characterize microtubule organization in whole chick embryos.

Main Methods:

• Confocal microscopy
• 3D image reconstruction
• Analysis of microtubule and actin organization

Main Results:

• Epiblast cells typically show radial microtubule arrays.
• Primitive streak cells exhibit predominantly polarized microtubule arrays.
• Primitive streak cells form rosette-like structures with actin accumulation at the center.
• Polarized cells in rosettes show protrusions from the center.

Conclusions:

• Cellular organization into higher-order structures, like rosettes, is proposed to aid cell ingression during gastrulation.
• Microtubule dynamics play a significant role in cell shape and movement during gastrulation.