Acts via the piwi-interacting RNA (piRNA) pathway which mediates the repression of transposable elements during meiosis by forming complexes composed of piRNAs and piwi proteins and governs the methylation and subsequent repression of transposons. Required for repression of transposons and neighboring genes in ovarian somatic and germline cells. Interacts with piwi. The zinc fingers are required for transcriptional silencing activity. Mutant females are viable but sterile (PubMed:23913922). They have small and severely deformed ovaries (PubMed:23913921, PubMed:23913922). Soma- and germline-specific transposable elements are severely derepressed in the ovary (PubMed:23913922). Ovaries lack a follicle cell layer and show misexpression of orb (PubMed:23913921). Belongs to the UPF0224 (FAM112) family.