Abstract
A mechanism is required to repress the expression and transposition of transposable elements (TEs) to ensure the stable inheritance of genomic information. Accumulating evidence indicates that small non-coding RNAs are important regulators of TEs. Among small non-coding RNAs, PIWI-interacting RNAs (piRNAs) serve as guide molecules for recognizing and silencing numerous TEs and work in collaboration with PIWI subfamily proteins in gonadal cells. Disruption of the piRNA pathway correlates with loss of proper genomic organization, gene expression control and fertility. Moreover, recent studies on the molecular mechanisms of piRNA biogenesis and on piRNA function have shown that piRNAs act as maternally inherited genic elements, transferring information about repressed TEs to progeny. These findings enable a molecular explanation of mysterious epigenetic phenomena, such as hybrid dysgenesis and TE adaptation with age. Here, I review our current knowledge of piRNAs derived from biochemical and genetic studies and discuss how small RNAs are utilized to maintain genome organization and to provide non-DNA genetic information. I mainly focus on Drosophila but also discuss comparisons with other species.
Highlights
Kuniaki Saito*A mechanism is required to repress the expression and transposition of transposable elements (TEs) to ensure the stable inheritance of genomic information
In eukaryotes, large proportions of genomes consist of various transposable elements (TEs) and their remnant sequences
In Drosophila, PIWI-interacting RNAs (piRNAs) were originally described as rasiRNAs that were defined as a subset of small non-coding RNAs discovered in testis and derived from repetitive genomic regions, such as suppressor of stellate, satellite DNA and TEs (Aravin et al, 2003)
Summary
A mechanism is required to repress the expression and transposition of transposable elements (TEs) to ensure the stable inheritance of genomic information. Recent studies on the molecular mechanisms of piRNA biogenesis and on piRNA function have shown that piRNAs act as maternally inherited genic elements, transferring information about repressed TEs to progeny. These findings enable a molecular explanation of mysterious epigenetic phenomena, such as hybrid dysgenesis and TE adaptation with age. I review our current knowledge of piRNAs derived from biochemical and genetic studies and discuss how small RNAs are utilized to maintain genome organization and to provide non-DNA genetic information.
Sign-in/Register to view highlights & summary Sign-in/Register to access full text options 
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a callDisclaimer: All third-party content on this website/platform is and will remain the property of their respective owners and is provided on "as is" basis without any warranties, express or implied. Use of third-party content does not indicate any affiliation, sponsorship with or endorsement by them. Any references to third-party content is to identify the corresponding services and shall be considered fair use under The CopyrightLaw.
