Related Experiment Video
Updated: Dec 28, 2025
09:10
Generation of Transgenic Hydra by Embryo Microinjection
Published on: September 11, 2014
14.7K
PIWI-piRNA pathway-mediated transposable element repression in Hydra somatic stem cells
Bryan B Teefy1, Stefan Siebert1, Jack F Cazet1
1Department of Molecular and Cellular Biology, University of California, Davis, California 95616, USA.
RNA (New York, N.Y.)
|February 21, 2020
Summary
The PIWI-piRNA pathway in Hydra suppresses transposable elements (TEs) in somatic stem cells. This somatic TE repression may contribute to Hydra's exceptional longevity and suggests an ancient role for this pathway.
Area of Science:
- Genetics
- Molecular Biology
- Developmental Biology
Background:
- Transposable elements (TEs) pose a threat to genome integrity.
- The PIWI-piRNA pathway is crucial for repressing TEs in animal germlines.
- Hydra possess somatic stem cells (epithelial stem cells) that express PIWI proteins.
Purpose of the Study:
- To investigate the role of the PIWI-piRNA pathway in somatic stem cells of Hydra.
- To determine if somatic cells utilize PIWI-piRNA for transposable element repression.
- To explore the potential contribution of somatic TE repression to Hydra's longevity.
Main Methods:
- Isolation and characterization of piRNAs from Hydra lacking germline stem cells.
- Epithelial knockdown of the Hydra piwi gene (hywi).
- Degradome sequencing and RNA immunoprecipitation (RIP) to detect PIWI-TE interactions.
Main Results:
- Somatic piRNAs in Hydra predominantly map to TE transcripts and share germline piRNA signatures.
- Knockdown of hywi led to increased TE expression in epithelial stem cells.
- Evidence of PIWI-mediated TE RNA cleavage and direct association between Hywi and TE transcripts was found.
Conclusions:
- The PIWI-piRNA pathway actively represses transposable elements in Hydra's somatic stem cell lineages.
- Somatic TE repression is proposed to contribute to the remarkable longevity of Hydra.
- The findings suggest that somatic TE repression is an evolutionarily conserved, ancestral function of the PIWI-piRNA pathway.
More Related Videos
07:53Application of RNAi and Heat-shock-induced Transcription Factor Expression to Reprogram Germ Cells to Neurons in C. elegans
Published on: January 1, 2018
8.1K
11:36Rapid and Efficient Generation of Recombinant Human Pluripotent Stem Cells by Recombinase-mediated Cassette Exchange in the AAVS1 Locus
Published on: November 20, 2016
10.1K
Related Concept Videos
02:57piRNA - Piwi-interacting RNAs
7.4K
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...
7.4K
01:29Somatic to iPS Cell Reprogramming
2.5K
Reprogramming alters the gene expression in somatic cells, transforming them into induced pluripotent stem (iPS) cells over several generations. Scientists can reprogram cells by introducing genes for four transcription factors—Oct4, Sox2, Klf4, and c-Myc (OSKM) by viral or non-viral methods. These factors are also known as Yamanaka factors after Shinya Yamanaka, who first generated iPS cells using mouse skin cells. Yamanaka was awarded the Nobel Prize in Physiology or Medicine in 2012...
2.5K
03:18Non-LTR Retrotransposons
13.0K
As the name suggests, non-LTR retrotransposons lack the long terminal repeats characteristic of the LTR retrotransposons. Additionally, both LTR and non-LTR retrotransposons use distinct mechanisms of mobilization. Non-LTR retrotransposons are further divided into two classes - Long interspersed nuclear elements (LINEs) and short interspersed nuclear elements (SINEs), both of which occur abundantly in most mammals, including humans. Some of the active non-LTR retrotransposons in humans are L1...
13.0K
01:32Chromatin Modification in iPS Cells
2.1K
Chromatin modification alters gene expression; therefore, scientists can add histone-modifying enzymes, histone variants, and chromatin remodeling complexes to somatic cells to aid reprogramming into pluripotent stem (iPS) cells.
Compact chromatin makes reprogramming difficult. Enzymes, such as histone demethylases and acetyltransferases, are often added during reprogramming to loosen the chromatin, making the DNA more accessible to transcription factors. Molecules that inhibit histone...
Compact chromatin makes reprogramming difficult. Enzymes, such as histone demethylases and acetyltransferases, are often added during reprogramming to loosen the chromatin, making the DNA more accessible to transcription factors. Molecules that inhibit histone...
2.1K
02:33Hedgehog Signaling Pathway
9.7K
The Hedgehog gene (Hh) was first discovered due to its control of the growth of disorganized, hair-like bristles phenotype in Drosophila, much like hedgehog spines. Hh plays a crucial role in the development of organs and the maintenance of homeostasis in both invertebrates and vertebrates. However, while Drosophila has only one Hh protein, mammals have multiple functional Hedgehog proteins - Sonic (Shh), Desert (Dhh), and Indian Hedgehog (Ihh). All of these homologous proteins have adapted to...
9.7K
02:15Experimental RNAi
7.2K
RNA interference (RNAi) is a cellular mechanism that inhibits gene expression by suppressing its transcription or activating the RNA degradation process. The mechanism was discovered by Andrew Fire and Craig Mello in 1998 in plants. Today, it is observed in almost all eukaryotes, including protozoa, flies, nematodes, insects, parasites, and mammals. This precise cellular mechanism of gene silencing has been developed into a technique that provides an efficient way to identify and determine the...
7.2K