High Dietary Sugar Reshapes Sweet Taste to promote Feeding Behavior in Drosophila melanogaster;

Cell Reports; Christina E. May…Monica Dus (she is big in Drosophila neurology)

Rational

1. Excess dietary sugar - but not just dietary sweetness, since a sweet sucralose diet (non-caloric sweetener) did not dull sweet taste - may alter the taste sensitivity
2. The decrease in sweet taste function align with overconsumption of sugar.
3. Neither sucrose nor non sweet, high-fat diet induce a lower taste sensation, so they reason that glucose metabolism is the key
4. Then, they focused on a specific metabolism pathway related with nutrient-sensing. Further, they knock down the enzyme OGT in this pathway, which restore taste sensation function and prevent overfeeding

Experimental approach:

1. Proboscis Extension Response (PER)
2. They measured In vivo, the real-time responses of the sweet Gr64 neurons to high sugar. Using presynaptic calcium sensor, which matched the magnitude and progression of sweet taste deficits as measured by PER
3. Optogenetics to activate Gr64 by light stimulation
4. They did RNA-seq, used iPAGE, a pathway discovery program to identify Gene Ontology (GO) terms, and did enrichment analysis stuff and stuff, but only described this with several sentences

Model suggested: we propose a model where excess dietary sugar, through the cell-autonomous action of OGT, leads to a decrease in the responses of the sweet taste cells to sugar, which lowers sweet taste sensation (Figure 7F). This weakening of sweet taste alters feeding patterns to promote obesity, providing a mechanism for how excess dietary sugar functions as a driver of obesity.