Taste-independent nutrient selection is mediated by a brain-specific Na(+)/solute co-transporter in Drosophila. Nature Neuroscience 16:526–528. doi: 10.1038/nn.3372

Animals can determine the nutritional value of sugar without the influence of taste. Here, we describe a Drosophila mutant that is insensitive to the nutritional value of sugars, but responds only to the concentration (i.e. sweetness). The affected gene encodes a sodium/solute cotransporter-like protein, designated dSLC5A11 (or cupcake), which is structurally similar to mammalian sodium/glucose cotransporters (SGLTs) that transport sugar across the intestinal and renal lumen. However, dSLC5A11 is prominently expressed in 10-13 pairs of R4 neurons of the ellipsoid body (EB) in the brain and functions in these neurons for selecting appropriate foods. We propose that dSLC5A11 and EB R4 neurons carry out a critical signaling function in responding to internal glycemic levels. Eating behavior is controlled by multiple factors including food palatability and nutritional needs. External chemosensory taste receptors primarily detect palatable food, but animals lacking taste receptors can still develop a preference for sugars based on their nutritional value1-6. Drosophila melanogaster can detect nutritive (i.e. metabolizable) sugars in the absence of peripheral sugar receptors6. This taste-independent nutrient selection pathway i