The ability to regenerate diseased, injured, or missing complex tissue is widespread throughout lower vertebrates and invertebrates; however, our knowledge of the molecular mechanisms that regulate this amazing ability is still in its infancy. Many recent papers have shown important roles for microRNAs in regulating regeneration in a number of species. The ability to detect and quantify miRNA expression fl uc-tuations at a single cell level in vivo in different cell types during processes like regeneration is very informative. In this chapter, we describe how to use a dual-fl uorescent green fl uorescent protein (GFP)-reporter/ monomeric red fl uorescent protein (mRFP)-sensor (DFRS) plasmid to quantitate the dynamics of specifi c miRNAs over time following miRNA mimic injection as well as during regeneration. In this bicistronic vector, the mRFP allows for verifi cation of miRNA expression, while the GFP functions as an internal control to normalize miRNA expression and thus obtain quantitative results. In addition, we demonstrate how this technique revealed dynamic miR-23a expression and function during tail regeneration.
- Sensor plasmids