Fig. 2

Fig. 2

M. leprae Triggers Myelin Dissociation

(A) Left, diagram of a spinal cord injection in an mbp:eGFP-CAAX larva (mbp), with fluorescent myelinating membrane, at 4 days post-fertilization (dpf). Transverse (middle) and sagittal (right) views of the region show the spinal cord (black), dorsal (d), and ventral (v) tracts of myelinated axons (green surrounding white axons), neuronal cell bodies (dark gray circles), and the ventral roots of spinal nerves (VR) surrounded by muscle (blue) and notochord (light gray). Arrows indicate intact myelin sheaths surrounding axons.

(B) Confocal image corresponding to (A). Scale bar, 10 μm.

(C) Representative confocal images of 4 dpf mbp larvae, 2 days post-infection (dpi) with ∼10⁴M. leprae, or ∼200 CFUs of M. marinum; arrowheads indicate myelin protrusions, quantified in (D). Scale bar, 10 μm.

(D) Mean number of myelin protrusions per animal following injection with PBS vehicle (veh), M. marinum, or M. leprae (^∗p < 0.05; one-way ANOVA, Bonferroni’s post-test).

(E) Mean bacterial burden of larvae from (C); measured by fluorescent pixel intensity like in Figure 1F.

(F and G) Representative confocal image (F) and rendering (G) of myelin protrusions in a 6 dpf larva 4 dpi with ∼10⁴M. leprae (Movie S1). Scale bar, 10 μm.

See also Table S1 and Movie S1.