Abstract: To investigate the perception and effects of specific amino acids on animals, we took Drosophila melanogaster as a model organism, measured the dietary preference and uptake of 20 amino acids as well as detected the effect of different amino acids on adult motility. We found that male and female Drosophila preferentially sense and consume different amino acids, and threonine specifically affects the motility of adult females. We then fed the third instar larvae with four dietary conditions (starvation, threonine, sucrose, and threonine + sucrose) and analyzed the differentially expressed genes between groups by transcriptome profiling. Gene Ontology annotation and Kyoto Encyclopedia of Genes and Genomes pathway analysis revealed that threonine affects steroid hormone and redox signaling. We further validated 8 genes by real-time fluorescence quantitative PCR in both larvae and adults,and found that the biological responses of threonine may depend on developmental stages. Our findings lay a foundation for additional in-depth investigation of the sensing and metabolic regulation of specific amino acids and provide clues of its molecular mechanism at the gene expression level.

Key words: amino acid metabolism, Drosophila melanogaster, dietary preference, threonine, transcriptome profiling