Adh-noc region cloned (Chia, Karp, McGill and Ashburner, 1985, J. Mol. Biol 186: 689-706) (coordinate 0 an EcoRI restriction site 1321 bp to the left of the start of transcription of the larval Adh transcript; positive values toward the centromere). The distal breakpoint of the Sco rearrangement is within the noc gene complex between the nocA and nocB components, such that nocB and nocC are brought into juxtaposition with sna. The molecular coordinates are complex, in that the distal break point as judged from the uninverted portion of noc is between coordinates -103.3 and -102.3; as judged from the noc-sna junction, however, it is between coordinates -108.5 and -107.8 kb, very close to the -107.8 position. Both these breakpoints are between nocA and nocB; the noc-Adh transposed segment extends from -107.8 to at least +40 kb (McGill, Chia, Karp and Ashburner, 1988, Genetics 119: 647-61). The proximal-most breakpoint of Tp(2;2)Sco is within 16 kb to the left of sna (Alberga).