May act as molecular guidance cue in cellular migration, and function may be mediated by interaction with roundabout homolog receptors. Detected as early as 8.25 dpc in the ventral neural tube. From 9.5 dpc to 11.5 dpc is expressed in the floor plate and motor columns. This pattern of expression continued until at least 17.5 dpc and remained weak. Rostrally, at 8.25 dpc is expressed in the ventral midline of the neural groove and in the neural fold prior to closure of the neural tube. Between 8.5 dpc and 9.5 dpc, expression is observed in the ventral side of the mesencephalon and metencephalon and in the commissural plate after closure of the neural tube. After 13.5 dpc, the expression of SLIT3 is weak in the developing CNS. At 9.5 dpc, SLIT3 is detected in the otic vesicle and in the clefts between the first and the second branchial arches. Between 10.5 dpc and 11.5 dpc is prominently expressed in the otic vesicle but decreased in the branchial clefts. From 13.5 dpc to 17.5 dpc, expression is observed in the cochlea, in the pigment layer of the retina, and in the olfactory epithelium. At 13.5 dpc expression is observed in the whisker follicle surrounding the bulb and shaft. In the developing limb is first detected at 10.5 dpc in distal limb bud mesenchyme. At this stage, is also observed in lateral ridge tissue flanking the limb bud. This pattern persisted through 11.5 dpc but unlike with SLIT2, expression is not observed in the inter-limb bud lateral ridge tissue. At 11.5 dpc, expression in both the fore- and the hindlimb is most intense in the distal anterior mesenchyme and in the proximal posterior cleft between the limb bud and the lateral ridge. At 13.5 dpc could be detected in the wrist and weakly in palm and proximal part of the digits excluding the tips of the digits.