What are piRNA clusters? What is produced from these loci? An Overview of piRNA Clusters and Their Role in Gene Regulation

An Overview of piRNA Clusters and Their Role in Gene Regulation

PiRNA clusters are genomic loci that produce small non-coding RNA molecules known as piRNAs (piRNA-induced silencing small RNA). These small RNA molecules play a crucial role in the regulation of gene expression, particularly in the germline cells of animals. According to a study published in 2016, piRNA clusters are “densely packed arrays of hundreds to thousands of piRNA-encoding transcripts” that are transcribed into primary piRNA transcripts (pptRNA) (Girard et al., 2016). These pptRNA transcripts are then processed by enzymes called Dicer and Drosha to produce the mature, 21-24 nucleotide long piRNAs.
PiRNAs are responsible for recognizing and silencing transposons, which are sequences of DNA that can “jump” from one location in the genome to another. This process, known as transposon silencing, is important for maintaining genome stability and preventing the deleterious effects of transposon activity (Girard et al., 2016). In addition to their role in transposon silencing, piRNAs have also been shown to play a role in the regulation of protein-coding genes, particularly during development (Liu et al., 2021). Cont….