BICD1 and cyst: In BicD and egl null alleles, the fusome properly forms, but no asymmetry of cytoplasmic markers occurs within the cyst (Suter and Steward, 1991; Ran et al., 1994; Mach and Lehmann, 1997; de Cuevas and Spradling, 1998; Huynh and Johnston, 2000).