Excision of the P{GawB} element.
adult mushroom body beta-lobe (with Df(2L)cact-255rv64)
ellipsoid body (with Df(2L)cact-255rv64)
bstE17B/Df(2L)cact-255rv64 adults have a strong central brain phenotype; the ellipsoid body is open ventrally and/or fusion of the left and right β lobes is seen.