Enables cell-cell adhesion mediator activity. Involved in several processes, including homophilic cell adhesion via plasma membrane adhesion molecules; nervous system development; and neuron cell-cell adhesion. Located in plasma membrane. Is expressed in several structures, including adult head; adult optic lobe; glial cell; medulla layer; and synaptic neuropil domain. Orthologous to human IGSF9 (immunoglobulin superfamily member 9).
FB Description
borderless (bdl) encodes a cell adhesion molecule that is required for glial extension and axon ensheathment. Its down-regulation by the products of tutl and Lar is required for photoreceptor axonal tiling and layer-specific target selection.