Figure 1.

TM3, TM6, and TM6B inversion breakpoints. Black circles indicate centromeres and left-facing arrows indicate an inverted segment. (A) The inversions carried by the third chromosome balancers TM3, TM6, and TM6B. Breakpoints that have been molecularly identified are shown as solid lines; those that are estimates are shown as dashed lines; numbers are cytological bands of breakpoints given in Lindsley and Zimm (1992). (B) The In(3LR)P88 (61A­1-2;89C2-4) rearrangement on TM6 is a previously unreported three-breakpoint rearrangement with a breakpoint at 3L:263,127–263,132 that bisects the gene Tudor-SN, a breakpoint at 3R:16,383,781 that bisects spineless, an allele previously reported to be carried by this chromosome (Duncan et al. 1998), and a breakpoint at 3L:97,494 that is intergenic. (C) In the In(3R)Hu (84B1;84F4;86C7-8) three-breakpoint rearrangement on TM6B, the breakpoint at 3R:8,287,181 bisects the noncoding RNA gene CR44318 while the 3R:10,742,076 breakpoint bisects TkR86C. The breakpoint at 3R:7,048,580 likely causes the Antp^Hu phenotype.