Fig. 2. In situ hybridization to whole testis. In situ hybridization to wild-type (A,C,E,G,I), topi^Z3-2139 (B,D,J) or topi^Z3-0707/Df(3R)by10 (F,H) mutant testes revealed that topi is an aly-class meiotic arrest gene. The distal ends of some mutant testes were broken off during the staining. Probes were anti-sense transcripts from cyclinA (A,B), cyclinB (C,D), twine (E,F), fzo (G,H) or Mst87F (I,J).