Fig. 1From: The emerging role of the piRNA/piwi complex in cancerpiRNA biosynthesis mechanism. Within the nucleus, two types of piRNA clusters are transcribed to produce the primary piRNAs, Zuc and its co-factors incised primary piRNAs producing piRNA intermediates with a 5′ uracil in Yb body. piRNA intermediates linked piwi that are cleavage by Zuc or Papi-dependent trimmer to form 3’end . Following methylation in cytoplasm, the mature piRNA-piwi complex is producted. Abbreviations: TSS: transcription start site; Zuc: zucchiniBack to article page