Misprocessed tRNA response targets pi RNA clusters

Germline PIWI ‐interacting RNA (pi RNA ) clusters have a characteristic transcriptional status; although they do not have their own promoters, both genomic strands are transcribed, while splicing and 3′ processing signals are neglected. How this transcription is maintained remains unknown. Molla‐Herman et al (2015) discovered that mutations in a tRNA processing factor cause the loss of transcription at some pi RNA clusters, leading to sterility in Drosophila melanogaster . This defect in pi RNA cluster transcription is restored by mutations in genes required for the DNA damage checkpoint or replication.