Expression of SOHLH1 and LHX8 proteins in 7-day-old ovaries. A–C) Anti-SOHLH1 antibodies (αSOHLH1) detected germ cell-specific transcription factor SOHLH1 in Postnatal Day 7 WT and Sohlh2+/– ovaries, as shown by brownish cytoplasmic staining of primordial follicles (PF), primary follicles (PrF), and secondary follicles (SF). SOHLH1 protein was not significantly expressed in Sohlh2–/– ovaries. D–F) Antibodies against LHX8 (αLHX8) localize LHX8 protein within the oocyte nuclei of PF, PrF, and SF in 7-day-old WT and Sohlh2+/– ovaries but not in Sohlh2–/– ovaries. Bar = 100 μm.