Structural analysis of multicellular organisms with cryo-electron tomography

Area of Science:

• Cell Biology
• Microscopy Techniques
• Developmental Biology

Background:

• Visualizing the intricate intracellular organization of tissues in multicellular organisms presents significant challenges.
• Cryo-electron tomography (cryo-ET) offers high-resolution 3D imaging capabilities but requires specialized sample preparation for complex biological specimens.

Purpose of the Study:

• To establish a robust protocol for cryo-electron tomography of intact multicellular organisms.
• To enable high-resolution visualization of intracellular structures within specific tissues at defined developmental stages.

Main Methods:

• Developed a workflow involving high-pressure freezing for sample vitrification.
• Utilized cryo-focused-ion-beam scanning electron microscopy (cryo-FIB-SEM) for cryogenic lamellar thinning.
• Applied cryogenic fiducial gold marker application post-milling for improved tomogram reconstruction.

Main Results:

• Successfully acquired high-resolution tomograms of vitrified Caenorhabditis elegans embryos and adult worms.
• Demonstrated the visualization of intracellular organization within selected tissues of intact specimens.
• Validated the protocol for preserving native cellular structures during imaging.

Conclusions:

• The developed cryo-ET protocol is effective for visualizing tissue architecture in multicellular organisms.
• This method provides unprecedented insights into cellular organization during development.
• The protocol facilitates the study of complex biological systems at the nanoscale.