One FISH, dFISH, Three FISH: Sensitive methods of whole- mount fluorescent in situ hybridization in freshwater planarians

Abstract

As freshwater planarians (flatworms) are further developed as a model system, the most valuable tool continues to be in situ hybridization (ISH) analysis of gene expression in whole mount adult animals (WISH). Multiple hurdles have been overcome during the optimization of a standard protocol for colorimetric, single color detections. However, gene function studies on planarians have evolved to the point where virtually all investigations require the analysis of multiple RNAs, simultaneously. Thus, considerable effort by the entire planarian community has been put forth to create adequate methodologies towards this goal. Here we summarize the field, methodological evolution, and describe a new method for more rapid and more sensitive detection of multiple RNAs by multi-fluorescent ISH.