The receptor tyrosine kinase gene linotte is required for neuronal pathwayselection in the Drosophila mushroom bodies

The linotte (lio) mutant was first isolated as a memory mutant. The lio gen e encodes a putative receptor tyrosine kinase (RTK), homologous to the huma n protein RYK. This gene has been independently identified in a screen for embryonic nervous system axonal guidance defects and called detailed (drl). Here, we report that linotte mutants present structural brain defects in t he adult central complex (CX) and mushroom bodies (MB). linotte and deraile d are allelic for this phenotype, which can be rescued by a drl(+) transgen e. The Lio RTK is expressed preferentially in the adult CX and MB. Our resu lts suggest that, analogous to its role within the embryonic nervous system , the Lio RTK is involved in neuronal pathway selection during adult brain development. (C) 1998 Elsevier Science Ireland Ltd. All rights reserved.