Fig. 1.

Comparison of the abundance of major bacterial taxa in the gut microbiota between summer and winter honeybees: Alphaproteobacteria (α-P), Bifidobacterium spp. (Bifi), Lactobacillus spp. (Lact), Lactobacillus Firm-5 clade only (Firm5), Gammaproteobacteria (γ-P), Gilliamella apicola (G.api), and Snodgrassella alvi (S.alvi1 and S.alvi2 using the primer pairs Neiss-F/Neiss-R and Beta-1009-qtF/Beta-1115-qtR, respectively). Interior worker honeybees were maintained for 18 d in cages (control conditions) before 16S rRNA gene quantification by qPCR in the hindgut. The y-axis represents the mean log₂ of fold changes (FC) in taxon abundance between summer and winter workers. Positive and negative values denote higher and lower abundance, respectively, in summer bees than in winter bees. Data were gathered from five independent colony replicates. Bars represent 95% confidence intervals. Stars indicate significant differences (P<0.05) by a paired Wilcoxon signed-rank test.