Carbohydrate epitopes involved in neural cell recognition are conserved between vertebrates and leech.

We are reporting on the evolutionary conservation of carbohydrate epitope families from vertebrate to leech. 1) The sulfated L2/HNK-1 carbohydrate epitope (Abo T, Balch CM (1981): J Immunol 127:1024-1029; Kruse J, Mailhammer R, Wernecke H, Faissner A, Timpl R, Schachner M (1984): Nature 311:153-155) is detected on glycoproteins of leech neurons using monoclonal antibodies (mAbs) L2 (336) and HNK-1. 2) Three rat mAbs, L3, L4, and L5, bind to leech nerve and muscle. The L3, L4, and L5 epitopes are localized to a group of mannosidic leech glycoproteins originally identified through mAbs Lan3-2 (Hogg N, Flaster M, Zipser B (1983): J Neurosci Res 9:445-457 and Laz6-189 (McRorie JW III, Zipser B (1988): "Cell Culture Approaches to Invertebrate Neuroscience." London: Academie Press, pp 33-52. MAb Lan3-2, which binds to a mannosidic epitope of the 130 kD sensory protein, has recently been shown to perturb the penetration of sensory afferents into the synaptic area of the central neuropile (Zipser B, Morell R, Bajt ML (1989): Neuron 3:621-630). The L3, L4, and L5 mAbs have been described to recognize different mannosidic epitopes on glycoproteins, some of which have been identified as neural cell adhesion molecules, and on astrocyte-specific proteoglycan from mouse brain (Kücherer A, Faissner A, Schachner M (1987): J Cell Biol 104:1597-1602; Fahrig T, Schmitz B, Weber D, Kücherer-Ehret A, Faissner A, Schachner M (1990): Eur J Neurosci 2:153-161; Streit A, Faissner A, Gehrig B, Schachner M (1990): J Neurochem In Press). The superposition of five different mannosidic epitopes on the axons of sensory afferents suggests complex, concerted participation of mannosidic epitopes in neuronal pathfinding and target recognition.