In our last lab journal club, we discussed the recent paper from Matt Piper (@piperlab) (along with the Ribeiro (@RibeiroLab), Partridge and Pletcher labs) in which they define a holidic diet for Drosophila research:

A holidic medium for Drosophila Melanogaster (2013) Nat Methods

Variations in fly food between different labs (and even within labs) can profoundly influence organismal phenotypes, particularly behavioural, lifespan and stress responses. So, this very nice, meticulous paper provides an important, defined set of dietary conditions upon which to carry out these type of experiments.

As larval growth researchers, we were particularly interested in the finding that on the holidic diet, larvae took several days longer to pupate than on a ‘normal’ yeast/sugar-based food. Moreover, this delayed development could be abrogated by adding a small amount of yeast extract to the holidic diet. So what is the magic yeast ingredient?  A gustatory cue? An olfactory cue?  – (given the recent paper from the Banerjee lab – coming up next on lab journal club – on how olfactory cues can influence physiological responses in larvae). Also Or83B (olfactory receptor) mutant larvae show a (modest) delay in development, which is more pronounced when they have to compete with wildtype flies to forage for food (from – Vosshall lab @pollyp1)