Transcription regulator of both male and female germline differentiation. Suppresses genes involved in spermatogonial stem cells maintenance, and induces genes important for spermatogonial differentiation. Coordinates oocyte differentiation without affecting meiosis I (By similarity). Forms both hetero- and homodimers with SOHLH1. Translocates from the cytoplasm into the nucleus and the translocation is dependent on SOHLH1 expression.