Lethality occurs during larval or pupal stages. Homozygous germline clones display cell lethality. Embryos derived from heterozygous mothers exhibit neither CNS or PNS defects.
su(f)4/su(f)2 flies are viable at 17-18oC, 24-25oC and 29-30oC, and are normal for the "pale bristles" phenotype.
su(f)4/su(f)2 females are fully viable, show a good but not complete suppression of f1 and are normal for the su(f)4 phenotype at all temperatures.
Homozygotes lethal at the larval stage; homozygous germ-line clones don't survive; no effect on development of peripheral or central nervous systems (Perrimon, Smouse, and Miklos, 1989). wa displays dilute apricot pigmentation in su(f)1/su(f)2 flies raised at 25oC but white eyes when raised at 18oC (Schalet and Lefevre, 1976). su(f)2 shown to be proximal to su(f)1 by recombination (Schalet).