Adapting and optimizing GCaMP8f for use in Caenorhabditis elegans

Area of Science:

• Neuroscience
• Molecular Biology
• Genetics

Background:

• Genetically encoded calcium indicators (GECIs) are crucial for observing cellular activity in real-time.
• Ultrafast and highly sensitive GECIs are needed for precise measurements of dynamic biological processes.
• Previous studies demonstrated novel GECIs (jGCaMP8) in mammals and Drosophila, but not in Caenorhabditis elegans.

Purpose of the Study:

• To develop and validate an optimized GCaMP8f construct for C. elegans.
• To compare the performance of GCaMP8f against GCaMP7f in C. elegans pharyngeal muscle.
• To assess the utility of GCaMP8f for detecting neuronal activity in C. elegans.

Main Methods:

• Constructing and generating C. elegans strains expressing GCaMP8f under the myo-2 promoter.
• Comparing GCaMP8f and GCaMP7f in pharyngeal muscle activity measurements.
• Validating GCaMP8f in touch receptor neurons to detect calcium transients.

Main Results:

• GCaMP8f demonstrated superior brightness and faster kinetics compared to GCaMP7f in C. elegans pharyngeal muscle.
• GCaMP8f did not disrupt the intrinsic contraction dynamics of the pharynx.
• GCaMP8f successfully detected robust calcium transients in touch receptor neurons, even with small stimuli.

Conclusions:

• GCaMP8f is a powerful new tool for C. elegans research, enabling the study of fast calcium dynamics.
• This indicator allows for high-resolution imaging across multiple cell types at low magnifications.
• GCaMP8f significantly advances the capability to investigate intracellular dynamics in C. elegans.