These results point to a dependence on human MBNL1 in the DM1 alternative splicing events used in the fly biological context, which, taken together with our previous observations, imply the conservation of the DM1 pathogenic pathway in D. melanogaster and support the use of these flies as DM1 spliceosensors. The gene discussed is MBNL1; the disease is myotonic dystrophy type 1.