A fluorescence in situ hybridization (FISH) protocol for stickleback tissue.

Area of Science:

• Developmental Biology
• Evolutionary Biology
• Neuroscience

Background:

• Threespine stickleback serve as a key model organism for behavioral and evolutionary research.
• Quantitative trait loci (QTL) and gene expression studies are increasingly identifying genes linked to ecologically significant traits in sticklebacks.
• Visualizing candidate gene expression is crucial for understanding these traits.

Purpose of the Study:

• To develop and present a reliable fluorescence in situ hybridization (FISH) protocol.
• To enable visualization of candidate gene expression in threespine stickleback tissues.
• To support ongoing behavioral and evolutionary studies using this model organism.

Main Methods:

• A detailed protocol for FISH on fresh or flash-frozen dissected threespine stickleback tissue.
• Includes guidelines for probe design and synthesis, sample embedding (cryo- or paraffin), sectioning, and hybridization.
• Protocol is optimized for brain tissue, with notes for adaptation to other tissues.

Main Results:

• The developed FISH protocol achieved specific labeling across various dissection and embedding conditions.
• Paraffin embedding demonstrated superior morphological preservation compared to cryo-embedding.
• Representative results showcase the expression of glial fibrillary acidic protein (GFAP), oxytocin receptor (OXTR), and tyrosine hydroxylase (TH) in the brain.

Conclusions:

• The presented FISH protocol is effective for visualizing gene expression in threespine stickleback.
• The method provides specific labeling and is adaptable for different tissues.
• This protocol will facilitate further research into the genetic basis of ecologically important traits in sticklebacks.