Strong transcriptional activator (PubMed:1284028). Plays an important role in spermatogenesis; essential for the progression of meiotic prophase I in spermatocytes (PubMed:27492080). Expressed predominantly in the spermatocytes and spermatids of adult testes. It is also present at lower levels in the ovary, brain, spleen, embryo and fetus. First detected between 2 and 3 weeks after birth, in parallel with the onset and progression of meiosis. It is expressed during oogenesis from the pachytene stage of meiotic prophase through to postmeiotic cells. Expression in testis starts from postnatal day 7 (PND7) and expression remains constant until PND28 (PubMed:27492080). Male germ-cell-specific conditional knockout results in complete male infertility and meiotic arrest in spermatocytes (PubMed:27492080). Spermatocytes show impaired chromosomal synapsis and DNA double-strand breaks (DSB) repair and a significantly reduced expression of DSB repair-associated genes (PubMed:27492080). Belongs to the krueppel C2H2-type zinc-finger protein family.