Vj. Auld et al., GLIOTACTIN, A NOVEL TRANSMEMBRANE PROTEIN ON PERIPHERAL GLIA, IS REQUIRED TO FORM THE BLOOD-NERVE BARRIER IN DROSOPHILA, Cell, 81(5), 1995, pp. 757-767
Peripheral glia help ensure that motor and sensory axons are bathed in
the appropriate ionic and biochemical environment. In Drosophila, per
ipheral glia help shield these axons against the high K+ concentration
of the hemolymph, which would largely abolish their excitability. Her
e, we describe the molecular genetic analysis of gliotactin, a novel t
ransmembrane protein that is transiently expressed on peripheral glia
and that is required for the formation of the peripheral blood-nerve b
arrier, In gliotactin mutant embryos, the peripheral glia develop norm
ally in many respects, except that ultrastructurally and physiological
ly they do not form a complete blood-nerve barrier. As a result, perip
heral motor axons are exposed to the high K+ hemolymph, action potenti
als fail to propagate, and the embryos are nearly paralyzed.