Transcriptomic differences of Dugesia japonica planarians fed a liver and red midge larvae mono diet

Freshwater planarians are an emerging model for toxicology and neuroscience because of their amenability to rapid behavioral screening and remarkable ability to regenerate a cephalized nervous system. As an invertebrate, planarians can help reduce the use of vertebrates in research; however, laboratories typically maintain planarians on diets of homogenized organic beef or chicken liver, raising ethical concerns with feeding a vertebrate diet. Organic liver is difficult to obtain and preparation methods vary, introducing intra- and interlaboratory variability. Here, we compare the transcriptomic differences of Dugesia japonica planarians maintained on commercially available red midge larvae (RML), a natural prey of freshwater planarians , compared to planarians fed a typical liver diet. We found only minor effects on gene expression. Because RML requires no preparation and sustains planarian populations long-term, this invertebrate diet can substitute liver and helps reduce the use of vertebrates in research.