Wing phenotype is additive with that of U1 and U2.
Wings curled upward; rarely overlaps wild type at 25oC, but frequently overlaps at 19oC. Curvature caused by the unequal contraction of the upper and lower epithelia during the drying period following emergence from the pupa case (Waddington, 1940). Flightless but thoracic innervation normal (Chiarodo, Reing and Saranchak, 1971). Expression decreased by larval crowding, increased by increased temperature during pupal development (Nozawa, 1956). Classifiable in single dose in triploids. Usually homozygous lethal but may emerge as dwarf with more extreme wing character. Effective lethal phase late embryo-early larva (Kidwell, 1972). Cy is readily revertable by both EMS and irradiation. In addition some balanced Cy chromosomes pick up suppressors of Cy in stock. RK1A.