HTT and Huntington disease: By means of nuclear magnetic resonance spectroscopy in a Drosophila HD model (UASHTT-EX1-PQ93/CyO), alterations in metabolomics were detected in several phenotypes expressing htt with different numbers of polyQ repeats, showing mainly perturbations in the development of classified adult ommatidia; these transgenic lines carried 20 (control), 93 (intermediate), and 127 (diseased) polyQ repeats.