Figure 4.

Ovaries from mitotic recombinations in syx/ovo ^D1 heterozygotes. ovo ^D1 is a dominant mutation that arrests ovariole development before stage 8. Examples of these rudimentary ovarioles are marked throughout with arrowheads and can be seen in A. Recombination in a P36-23/ovo ^D1 fly produces P36-23 homozygous clones in which follicles reach maturity and oocytes are produced (B, and marked with arrows throughout) alongside ovo ^D1-arrested ovaries. Mature ovarioles are also seen in syx ^L266 clones (C) but were not seen in syx^L371 clones (D). syx ^L371 is therefore either a rudimentary ovary mutant comparable to ovo ^D1, or syx ^L371 is cell lethal, leaving only ovo ^D1 follicles. Mature oocytes are produced from syx ^L371 ovary clones that express syx on a second chromosome transgene (E). The genotype of these flies is HS-FLP; HS-GAL4:UAS-syx; syx ^L371-82BFRT/ovo ^D1-82BFRT. Siblings of these flies that do not carry the transgene show no developed ovarioles (F). All of the ovaries shown were stained with FITC-conjugated phalloidin to allow visualization of the ovarioles. Bar, 200 μm.