Aub guided by piRNAs ensures genome integrity by cleaving retrotransposons, and genome propagation by trapping mRNAs to form the germplasm that instructs germ cell formation. Arginines at the N-terminus of Aub (Aub-NTRs) interact with Tudor and other Tudor domain-containing proteins (TDRDs). Aub-TDRD interactions suppress active retrotransposons via piRNA amplification and form germplasm via generation of Aub-Tudor ribonucleoproteins. Here, we show that Aub-NTRs are dispensable for primary piRNA biogenesis but essential for piRNA amplification and that their symmetric dimethylation is required for germplasm formation and germ cell specification but largely redundant for piRNA amplification.

Central European Institute of Technology Brno Czech Republic

Computational Medicine Center Sidney Kimmel Medical College Thomas Jefferson University Philadelphia PA USA

Departments of Genetics Perelman School of Medicine University of Pennsylvania Philadelphia PA USA

Division of Neuropathology Departments of Pathology and Laboratory Medicine University of Pennsylvania Philadelphia PA USA

Laboratory of Genetics and Genomics National Institute on Aging Intramural Research Program National Institutes of Health Baltimore MD USA

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