The axons of olfactory sensory neurons (OSNs) project to individually identifiable neuropil regions called protoglomeruli in the Olfactory Bulb (OB), and later segregate into smaller odorant receptor (OR)-specific neuropils called glomeruli. We are investigating the contributions that the highly conserved axon guidance related Slits and Robos make to OSN axon guidance through the use of F0 CRISPR/Cas9 gene knockdowns in embryonic zebrafish. We observe striking abnormal midline crossing of transgene labelled OMP:RFP and TRPC2:Venus axons in robo2 knockdowns, consistent with a role for robo2 in preventing midline crossing during development. Transgene-labeled BacOR111-7:Gal4 OSN axons escape from the Central Zone protoglomerulus in slit1a;slit1b double knockdowns. The rate of these ectopic misprojections in slit1a;slit1b double knockdowns is significantly elevated as compared to wildtype, slit1a, or slit1b knockdowns. These findings suggest that slit1a and slit1b normally work together to keep OSN axons confined to the Central Zone protoglomerulus.