Table 1.
Production of microsporidian spores in honey bees treated with varying concentrations of fumagillin.
Figure 1.
Mature Nosema ceranae and Nosema apis spores accumulated in hindgut contents of honey bee hosts.
(A) Average total number of accumulated spores. Treatment protocols included positive controls (N. apis or N. ceranae infection, no fumagillin), and microsporidia plus 0.01× or 0.001× recommended concentrations of fumagillin. The recommended concentration suppressed spore production below the detection limit and is not included on the graph. One trial was conducted for the positive control 18 days post inoculation (dpi) and for all treatments 20 dpi; therefore, statistical evaluation was not performed for 18 and 20 dpi. Spore production significantly higher than the positive control is labeled “a”; spore production significantly lower than the positive control is labeled “b”. (B) Linear regression of spore accumulation in the hindgut contents, 10–16 dpi. Arrows indicate the difference between N. ceranae and N. apis within a treatment. *Slope represents daily spore accumulation.
Figure 2.
Midgut spore counts of N. ceranae inoculated bees treated with fumagillin.
(A) Spore counts at descending fumagillin concentrations. Results from six trials were pooled. The regression matches the quadratic model (P<0.001), R2 = 0.418. (B) Normalized data setting the positive control at 100% for each trial (P<0.001; R2 = 0.272). Dashed lines represent midgut spore counts in infected, untreated bees.
Figure 3.
Alignment of translated MetAP2 genes.
Circled amino acids are fumagillin binding sites; those marked with stars are metal ion binding sites. Species represented are Encephalitozoon cuniculi, Apis mellifera, Nosema apis, Nosema bombi, Nosema ceranae, Drosophila melanogaster, Encephalitozoon intestinalis, Encephalitozoon hellem, Encephalitozoon species, Homo sapiens, and Saccharomyces cerevis.
Figure 4.
2-dimensional electrophoresis of midgut tissues of honey bees fed different concentrations of fumagillin.
(A) 0.0×, no fumagillin (control). (B) 1.0× = manufacturer's recommended fumagillin concentration, 25 mg/L. (C) 0.01× the recommended concentration. (D) 0.001× the recommended concentration. Arrows indicate the proteins identified in Table 2. Disruptions of normal protein profiles corresponding to the fumagillin concentrations are observable.
Table 2.
Proteins identified from infected midgut tissues in honey bees fed varying concentrations of fumagillin using 2D-gel electrophoresis (Figure 3).