Fig. 5. Germline-associated somatic cell nuclei divide ectopically in myt1 mutant testes. (A,D) Somatic cyst cells stained with anti-Eya (green) and anti-PH3 (B, F, red) antibodies. Increased numbers of cyst cell nuclei were seen in the myt1 mutants (D, green) relative to controls (A); PH3-positive cyst cells were also detected in the mutants (D, arrows). (B,E) Cyst cells and spermatocytes stained with anti-Eya (green) and anti-Aly (red) antibodies. Extra cyst cells associated with Aly-positive spermatocytes were seen in myt1 mutants (E, arrows), when compared with controls (B). (C,F) Optical sections through seminal vesicles stained to visualize DNA (blue, arrow shows proximal end of vesicle). No sperm were present in the myt1 mutant seminal vesicle (F), in contrast to controls, which were full of mature sperm (C). Scale bar: in B, 40 µm for A,B,D,E; in C, 20 µm for C,F.