Potencies of effector genes in silencing odor-guided behavior inDrosophila melanogaster

Abstract

The genetic toolbox in Drosophila melanogaster offers a multitude of different effector constructs to silence neurons and neuron populations. In this study, we investigated the potencies of several effector genes -when expressed in olfactory sensory neurons (OSNs) -to abolish odor-guided behavior in three different bioassays. We found that two of the tested effectors (tetanus toxin and Kir2.1) are capable of mimicking the Orco mutant phenotype in all of our behavioral paradigms. In both cases, the effectiveness depended on effector expression levels, as full suppression of odorguided behavior was observed only in flies homozygous for both Gal4-driver and UAS-effector constructs. Interestingly, the impact of the effector genes differed between chemotactic assays (i.e. the fly has to follow an odor gradient to localize the odor source) and anemotactic assays (i.e. the fly has to walk upwind after detecting an attractive odorant). In conclusion, our results underline the importance of performing appropriate control experiments when exploiting the D. melanogaster genetic toolbox, and demonstrate that some odor-guided behaviors are more resistant to genetic perturbations than others.

Drosophila Neuropeptide F Signaling Independently Regulates Feeding and Sleep-Wake Behavior

“…However, NPF SK2 mutants did not exhibit a significant change in wake behavior during the same interval compared to fed controls (Figure 2A, B), establishing that NPF is required for starvation-induced sleep loss during this period. Notably, Kir2.1 -mediated inhibition of NPF + neurons either constitutively or exclusively as adults did not recapitulate the NPF mutant phenotype, suggesting either compensatory effects in these neurons or incomplete silencing of neuron function (Retzke et al, 2017). Taken together, these observations suggest that NPF signaling plays a minor role in modulating sleep when nutrients are replete, yet may be recruited to promote wakefulness under limited or challenging nutritional environments.…”

Antennal Enriched Odorant Binding Proteins Are Required for Odor Communication in Glossina f. fuscipes

“…The flies were introduced into the cage 20 min before loading the attractive odor and the mineral oil. Flies were allowed to choose between the attractive source and the control for 24 h; afterwards, the attraction was scored and the attraction index (AI) was calculated using: AI = (N odour − N control )/N total (1) where N odour corresponds to the number of flies trapped at the odor source, N control is the number of flies trapped at the control and N total is the number of flies used for the assay [77]. The significant differences between the attraction indices were noted using the analysis of variance (ANOVA) test followed by Tukey's HSD (Honestly Significant Difference) post hoc test, owing to the normality of the data (Shapiro test: p > 0.05) and the homogeneity of the variance (Levene test: p > 0.05).…”