Pirna Biogenesis
Pirna Biogenesis - Related Videos
02:57
piRNA - Piwi-interacting RNAs
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2020
PIWI-interacting RNAs, or piRNAs, are the most abundant short non-coding RNAs. More than 20,000 genes have been found in humans that code for piRNAs while only 2000 genes have been found for miRNAs. piRNAs can act at the transcriptional and post-transcriptional levels and have a vital role in silencing transposable elements present in germ cells. They are also involved in epigenetic silencing and activation. Previously, they were thought to function only in germ cells but new evidence suggests...
08:06
Study of Phagolysosome Biogenesis in Live Macrophages
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Cited by 6 •
2014
Phagocytic cells play a major role in the innate immune system by removing and eliminating invading microorganisms in their phagosomes. Phagosome ...
13:48
Studying Membrane Biogenesis with a Luciferase-Based Reporter Gene Assay
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Cited by 6 •
2008
Here, we describe procedures for studying changes in phagocytosis-induced gene expression with a luciferase-based reporter gene approach using the Dual-GloTM Luciferase Assay System from Promega.
12:15
The C. elegans Intestine As a Model for Intercellular Lumen Morphogenesis and In Vivo Polarized Membrane Biogenesis at the Single-cell Level: Labeling by Antibody Staining, RNAi Loss-of-function Analysis and Imaging
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Cited by 13 •
2017
The transparent C. elegans intestine can serve as an "in vivo tissue chamber" for studying apicobasal membrane and lumen biogenesis at the single-cell and subcellular level during multicellular tubulogenesis. This protocol describes how to combine standard labeling, loss-of-function genetic/RNAi and microscopic approaches to dissect these processes on a molecular level.
10:30
The C. elegans Excretory Canal as a Model for Intracellular Lumen Morphogenesis and In Vivo Polarized Membrane Biogenesis in a Single Cell: labeling by GFP-fusions, RNAi Interaction Screen and Imaging
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Cited by 6 •
2017
The C. elegans excretory canal is a unique single-cell model for the visual in vivo analysis of de novo polarized membrane biogenesis. This protocol describes a combination of standard genetic/RNAi and imaging approaches, adaptable for the identification and characterization of molecules directing unicellular tubulogenesis, and apical membrane and lumen biogenesis.
FAQs
Primary processing converts long single-stranded precursor transcripts into mature piRNAs, creating the molecules that can associate with PIWI proteins. Zucchini is a key factor in this route, so its activity represents an important point at which precursor handling influences the supply of functional guides. Examining this step helps distinguish initial piRNA formation from later target-dependent amplification.
The ping-pong cycle uses complementary recognition between piRNAs and their targets to promote additional piRNA production through PIWI proteins. Unlike primary processing, which starts from long precursor transcripts, this mechanism couples target recognition to amplification. Its importance lies in linking sequence-specific targeting with expansion of the piRNA population directed against complementary transposable-element transcripts.
PIWI loading gives each mature piRNA a sequence-guiding role, but silencing can occur at different levels. Recognition may lead to cleavage of a target transcript, repression of transcription, or modification of chromatin. These outcomes connect RNA sequence information to either direct transcript control or regulation of genomic activity, allowing the pathway to suppress transposable elements through more than one mechanism.
A focused analysis can follow the pathway in stages: assess long precursor transcripts, examine their conversion into mature piRNAs, evaluate association with PIWI proteins, and then ask whether complementary targets undergo silencing. Including both primary processing and the ping-pong cycle helps separate initial production from amplification, while measuring cleavage, transcriptional repression, or chromatin modification reveals the level of control.
Animal germ cells depend on this pathway to restrain transposable elements while germline development proceeds. Effective production and PIWI loading provide sequence-specific guides that can reduce transposon activity through transcript cleavage, transcriptional repression, or chromatin modification. Consequently, studying the pathway connects molecular RNA processing with broader biological outcomes involving fertility and preservation of genome integrity.
When precursor processing, target-dependent amplification, or PIWI-guided silencing is disrupted, transposable-element control may weaken. The resulting concern is not limited to RNA production: failures in transcript cleavage, transcriptional repression, or chromatin modification can compromise genome stability. For this reason, piRNA biogenesis research provides a framework for relating altered transposon regulation to germline defects, fertility problems, and disease.