Modeling Heart Diseases in Drosophila

Abstract

Fragile X mental retardation protein (FMRP) plays an important role in heart development and disease. Here we set out to create a Drosophila model of heart disease that will complement the existing mouse model based on Fragile X protein deficiency. Proteins within the Fragile X family are RNA binding proteins that control the translation of specific RNAs. Previous studies have shown that loss of Fragile X mental retardation protein, autosomal homolog 1 (FXR1) leads to heart phenotypes in the mouse. The Drosophila model will allow us to perform rapid genetic rescue experiments to identify specific targets of FMR1, the only type of FMR expressed in the fly, that are responsible for creating the structural and functional defects when FMR1 is repressed. To create a model of heart disease in the fly, we knocked down FMR1 and examined its effects by measuring the heart rate in early pupae. We discovered that the total loss of function for FMR1 leads a decreased heart rate. Interestingly, heterozygous loss of function (LOF) mutants exhibited a significant decrease in heart rate that could be partially rescued by inserting hFXR1, a human homolog of FMRP.