Qingying Menga, Yumei Zhuanga, Zhe Yinga, Rahul Agrawala, Xia Yanga, , , Fernando Gomez-Pinillaa,b, ,
New findings regarding the neurological regulation of
feeding rate suggest interesting factors behind fruit fly nutrition and
obesity. After a screening of GAL4 lines in adult Drosophila brains, one line (Taotie-GAL4)
was identified to have an impact on food intake. Further study showed that activation
of Taotie neurons increased food
intake over five-fold when compared to control flies. However, when starved for
over 60 hours, Taotie activated flies
showed no difference in food intake compared to equally starved non-activated
flies. This suggests that activation of the Taotie
neuron is involved in hunger response normally. Activation of the Taotie neuron in flies that were
sufficiently nourished resulted in fly obesity. Interestingly, inactivation of
activated neurons effectively reversed the obese trend, as deactivated flies not
only returned to normal feeding habits, but effectively controlled their food
intake until normalcy was established.
Turnbaugh, P. J., Hamady, M., Yatsunenko, T., Cantarel, B. L., Duncan, A., Ley, R. E., … Gordon, J. I. (2009). A core gut microbiome in obese and lean twins. Nature, 457(7228), 480–484. http://doi.org/10.1038/nature07540
Environmental factors play a more significant factor on determining host gut microbiome composition than genetics. Tests on on five inbred mouse strains systematically fed controlled diets sowed that despite differences in genotype, the microbiota in each strain was in fact altered. Additionally, by varying the host’s controlled diet, data demonstrates that microbiota is not determined by a single initial food source but can be altered over time, further supporting that environmental factors including changes in diet will more significantly impact microbiome than host genotype.
Because many species (usually non-mammal species) have shown presence of a core gut microbiota, this study tested whether such was also the case within different Drosophila species. Results showed an absence of core microbiota and that bacterial species co-occurred less frequently than would be considered random. Results suggest that gut bacteria do not co-evolve with host Drosophila and would be unhelpful if used to track phylogeny among host species.
Stephanie M. Pontier, Francois Schweisguth. (2015) A Wolbachia-Sensitive Communication between Male and Female Pupae Controls Gamete Compatibility in Drosophila. Current Biology 25(18):2339-2348. doi:10.1016/j.cub.2015.07.052
Tony L. Parkes, Andrew J. Elia, Dale Dickinson, Arthur J. Hilliker, John P. Phillips & Gabrielle L. Boulianne. (1998) Extension of Drosophila lifespan by overexpression of human SOD1 in motorneurons. Nature 19:171-174. doi:10.1038/534.
Rivka L. Glaser, Karl W. Broman, Rebecca L. Schulman, Brenda Eskenazi, Andrew J. Wyrobek, Ethylin Wang Jabs. (2003) The Paternal-Age Effect in Apert Syndrome Is Due, in Part, to the Increased frequency of Mutations in Sperm. AJHG 73(4):939-947. doi: http://dx.doi.org/10.1086/378419