Fluorescence microscopy was performed as described (59 (link)). Mycobacterial cording and macrophage numbers were assessed in the trunk of the larvae using a Nikon Eclipse E600 upright microscope fitted with Nikon Plan Fluor 10X 0.3 NA and Nikon Plan Fluor 20X 0.5 NA objectives. For laser scanning confocal microscopy, anesthetized larvae were embedded in low-melting-point agarose as previously described (6 (link)). A Nikon A1R confocal microscope with a Plan Apo 20X 0.75 NA objective was used to generate 35-40 mm z-stacks consisting of 0.3-2-mm optical sections. The galvano scanner was used for all static imaging and for time-lapse imaging of the caudal hematopoietic tissue (CHT, area located between the cloaca and the beginning of the caudal fin). Images were acquired with NIS Elements (Nikon). A heating chamber (Oko-labs) adapted to the microscope was used to maintain temperature at 28.5°C during imaging. Confocal images are pseudocolored to facilitate visualization.