CUBITUS INTERRUPTUS [ci]
Lindsley & Grell, 1972, p. 51
location: 4-0 (most proximal mutant in 4).
discoverer: Tiniakov and Terentieva, 30b.
references: Terentieva, 1931, Zh. Eksperim. Biol. 7: 187-90 (fig.). Tiniakov and Terentieva, 1933, Genetics 18: 117-20 (fig.). Bridges, 1935, Biol. Zh. (Moscow) 4: 401-20. Sturtevant, 1951, Proc. Natl. Acad. Sci. U.S. 37: 405-7. Stern and Kodani, 1955, Genetics 40: 343-73 (fig.).
phenotype: Vein L4 shows one or more gaps both distal and proximal to posterior crossvein, generally nonterminal. Anterior crossvein shortened or absent. Other gaps and scattered branch veins in region of crossveins. At l9oC nearly all flies have a mutant phenotype; at 25oC there is slight overlap with wild type; at 30oC virtually all flies are wild type. Dosage effect such that ci/0 haplo-4's are more extreme than ci/ci diplo-4's, which are more extreme than ci/ci/ci triplo-4's. For interactions of ci with en, H, ve and cg, see House, 1953, Genetics 38: 199-215, 309-27; 1955, Anat. Record 122: 471; 1959, Genetics, 44: 516; 1961, Genetics, 46: 871. Expression of ci sensitive to genetic background; selection possible for more and less extreme phenotypes (House and Yeatts, 1962, Genetics 47: 960). Phenotypic effect visible in prepupa by absence of the lower longitudinal vein. RKl at l9oC and higher rank with higher temperatures.
cytology: Placed in salivary chromosome region 101F2-102A5, on the basis of its inclusion in Df(4)M63a = Df(4)101F2-102A1;102A2-5.
other information: The expression of ci+ can be altered in direction of ci by certain chromosome rearrangements that have one break in vicinity of ci locus. Rearranged fourth chromosomes carrying a mutant allele of ci, R(ci), may also show altered expression of gene (Stern and Kodani, 1955). R(ci) and R(ci+) terminology not retained here; interaction with ci included in descriptions of aberrations involving chromosome 4.
color figure: P. A. Otto (original)
b & w figure: Wings showing from no interruption (wild-type wing at extreme right) to complete absence (extreme left) of the cubital vein. Stern and Kodani, 1955, Genetics 40: 343-73.