Lindsley & Grell, 1972, p. 91
discoverer: Bridges, 12k19.
references: Morgan and Bridges, 1916, Carnegie Inst. Wash. Publ. No. 237: 58 (fig.).
phenotype: Bristles shortened, gnarled, and bent, with ends split or sharply bent. Hairs similarly affected, but this is visible only at high magnifications. Treatment with methylurea causes normal bristle formation (De Marinis). Developmental studies [Lees and Waddington, 1942, Proc. Roy. Soc. (London) Ser. B 131: 87-110 (fig.); Lees and Picken, 1945, Proc. Roy. Soc. (London), Ser. B 132: 396-423 (fig.)] show nature of pupal bristle secretion is affected. Suppressed by su(f). RK1.
cytology: According to Demerec and Sutton, bands 15F1-5 are involved (Demerec, Kaufmann, Fano, Sutton, and Sansome, 1942, Carnegie Inst. Wash. Year Book 41: 191). This can be narrowed to 15F1-3 on the basis of Df(1)f257-5 = Df(1)15E7-F1;15F2-4.
other information: Green (1955, Proc. Natl. Acad. Sci. U.S. 41: 375-79; 1956, Proc. Natl. Acad. Sci. U.S. 42: 73-77) showed the forked mutants can be assigned to either of two pseudoallelic series. f is a member of the right series. Back mutations to f+ occur spontaneously and their incidence is not increased by X rays (Green, 1959, Proc. Natl. Acad. Sci. U.S. 45: 16-18; Lefevre and Green, 1959, Genetics 44: 769-76).
color figure: P. A. Otto (original)
b & w figure: Edith M. Wallace, unpublished
photograph: P. A. Otto (original)