Commensal bacteria and essential amino acids control food choice behavior and reproduction
Fig 7
Commensal bacteria do not seem to change the levels of essential amino acids (eAAs) in the host.
(A) Histidine (His), isoleucine (Ile), and valine (Val) concentrations in the heads of flies prefed on complete holidic medium (green) or holidic medium lacking His, Ile, or Val (blue), without (empty columns) or with (filled columns) commensals pretreatment. The columns represent the mean and the error bars the standard error of the mean of three independent experiments. Filled black circles represent complete holidic medium or pretreatment with the bacteria mix. Open black circles represent no pretreatment with bacteria mix. Amino acid (AA) deprivation is indicated as –histidine (–His), –isoleucine (–Ile), or –valine (–Val). Significance was tested using the unpaired t test with Bonferroni correction. Not significant (ns) p > 0.05, * p < 0.05, ** p < 0.01. (B) Model of the impact of eAAs on food choice and reproduction, depending on the presence of the microbiota of the host. The nervous system is highlighted in turquoise, AAs in orange, and commensal bacteria in purple. Arrow weight from the proboscis to the food drops indicate amount of feeding, and the number of eggs reflect the reproductive output. The orange and purple arrows indicate potential effects of eAAs and metabolites, respectively, at the level of the nervous and reproductive systems. Metabolite X refers to a hypothetical metabolite mimicking the presence of AAs. Underlying data used in this Fig are provided in S1 Data.