Microbeam irradiation of the C. elegans nematode

Area of Science:

• Radiation biology
• Genetics
• Model organisms

Background:

• In vitro models are limited in capturing complex radiation responses.
• The bystander effect, a non-targeted radiation response, requires in vivo study.
• Genetically amenable model organisms offer advantages for radiation research.

Purpose of the Study:

• To develop and validate an in vivo model for studying radiation-induced bystander effects.
• To investigate the spatial characteristics of radiation responses in a whole organism.
• To utilize proton microbeam technology for precise in vivo irradiation.

Main Methods:

• Utilized the nematode C. elegans with a Green Fluorescent Protein (GFP) reporter for the hsp-4 gene.
• Developed a proton microbeam technique for site-specific irradiation of C. elegans.
• Irradiated specific sites in the worm's tail with 3 MeV protons.

Main Results:

• Gamma-rays induced a dose-dependent stress response (increased GFP expression) in C. elegans.
• Site-specific proton irradiation led to enhanced GFP expression in non-targeted tissues.
• The bystander effect, indicated by increased GFP expression, was observed up to >100 micrometers from the irradiation site.

Conclusions:

• C. elegans is a suitable in vivo model for studying radiation bystander effects.
• Proton microbeam irradiation can induce measurable non-targeted responses in vivo.
• This study demonstrates the feasibility of investigating spatial radiation responses in a whole organism.