Has a role in intercellular carbohydrate-mediated cell adhesion. Expressed by a subset of glial cells found at the midline of the embryo stage 12 nervous system. Expression is highest during the formation of the embryonic axonal commissures, a process requiring midline glial cell function (at protein level). Flies exhibit disruption of the formation of commissural pathways and shows delays the completion of longitudinal pathfinding. The disruption in commissure formation is accompanied by reduced axon-glial contact, such that extending axons grow on other axons and form a tightly fasciculated bundle that arches over the midline.