The genetic variant Voila(1) causes gustatory defects during Drosophila development

Voila(1), an enhancer-trap strain in Drosophila melanogaster, expresses GAL 4 in most gustatory neurons, both before and after metamorphosis. Voila(1) expression starts at embryonic stage 10. In the periphery, it labels larval gustatory sensilla in the antennomaxillary complex as well as in the phary nx. GAL4 is also expressed in the CNS in a manner that prefigures expressio n in adult flies. Most Voila(1/1) homozygotes die between second larval ins tar and early adulthood. Moreover, escaping Voila(1/1) larvae do not show g ustatory responses to NaCl and sucrose. The simultaneous rescue of normal l arval gustation together with adult viability after removal of the transpos able PGAL4 element suggests that both these phenotypes are caused by the sa me inserted element.