Jove
Visualize
Contact Us
JoVE
x logofacebook logolinkedin logoyoutube logo
ABOUT JoVE
OverviewLeadershipBlogJoVE Help Center
AUTHORS
Publishing ProcessEditorial BoardScope & PoliciesPeer ReviewFAQSubmit
LIBRARIANS
TestimonialsSubscriptionsAccessResourcesLibrary Advisory BoardFAQ
RESEARCH
JoVE JournalMethods CollectionsJoVE Encyclopedia of ExperimentsArchive
EDUCATION
JoVE CoreJoVE BusinessJoVE Science EducationJoVE Lab ManualFaculty Resource CenterFaculty Site
Terms & Conditions of Use
Privacy Policy
Policies

Related Concept Videos

Non-LTR Retrotransposons03:18

Non-LTR Retrotransposons

11.4K
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...
11.4K
LTR Retrotransposons03:08

LTR Retrotransposons

17.4K
LTR retrotransposons are class I transposable elements with long terminal repeats flanking an internal coding region. These elements are less abundant in mammals compared to other class I transposable elements. About 8 percent of human genomic DNA comprises LTR retrotransposons. Some of the common examples of LTR retrotransposons are Ty elements in yeast and Copia elements in Drosophila.
The internal coding region of LTR retrotransposons and their mechanism of transposition closely resembles a...
17.4K
DNA-only Transposons02:57

DNA-only Transposons

14.4K
DNA-only transposons are called autonomous transposons since they code for the enzyme transposase that is required for the transposition mechanism. Insertion of transposons can alter gene functions in multiple ways. They can mutate the gene, alter gene expression by introducing a novel promoter or insulator sequence, introduce new splice sites, and change the mRNA transcripts produced, or remodel chromatin structure.
The donor site from where the transposon is excised is either degraded or...
14.4K
piRNA - Piwi-interacting RNAs02:57

piRNA - Piwi-interacting RNAs

6.8K
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...
6.8K
Inheritance of Chromatin Structures03:17

Inheritance of Chromatin Structures

6.2K
Epigenetics is the study of inherited changes in a cell's phenotype without changing the DNA sequences. It provides a form of memory for the differential gene expression pattern to maintain cell lineage, position-effect variegation, dosage compensation, and maintenance of chromatin structures such as telomeres and centromeres. For example, the structure and location of the centromere on chromosomes are epigenetically inherited. Its functionality is not dictated or ensured by the underlying...
6.2K
Gene Conversion02:08

Gene Conversion

9.7K
Other than maintaining genome stability via DNA repair, homologous recombination plays an important role in diversifying the genome. In fact, the recombination of sequences forms the molecular basis of genomic evolution. Random and non-random permutations of genomic sequences create a library of new amalgamated sequences. These newly formed genomes can determine the fitness and survival of cells. In bacteria, homologous and non-homologous types of recombination lead to the evolution of new...
9.7K

You might also read

Related Articles

Articles linked to this work by shared authors, journal, and citation graph.

Sort by
Same author

Extrachromosomal circular DNA.

Current biology : CB·2026
Same author

Circular DNA in eukaryotes (ecDNA and eccDNA included): Fusion Conference provides interdisciplinary insights into an emerging field.

Trends in genetics : TIG·2026
Same author

BRCA1-A and LIG4 complexes mediate ecDNA biogenesis and cancer drug resistance.

Proceedings of the National Academy of Sciences of the United States of America·2026
Same author

Retrotransposon activation during spermatogenesis achieves massive ecDNA biogenesis but rare integration.

Genes & development·2026
Same author

National trends in the utilization of office-based transnasal esophagoscopy.

American journal of otolaryngology·2025
Same author

Extrachromosomal Circular DNA: A Mobile Genetic Element Shaping Host Biology.

Annual review of cell and developmental biology·2025

Related Experiment Video

Updated: Jun 16, 2025

Screening Sperm for the Rapid Isolation of Germline Edits in Zebrafish
05:55

Screening Sperm for the Rapid Isolation of Germline Edits in Zebrafish

Published on: February 10, 2023

1.2K

Safeguarding spermatogenesis from retrotransposon insertions by forming ecDNA.

Lauren Tracy1, Zz Zhao Zhang1

  • 1Department of Pharmacology & Cancer Biology, Duke University School of Medicine, Durham, USA.

Biorxiv : the Preprint Server for Biology
|June 4, 2025
PubMed
Summary

Retrotransposons drive genome innovation but can cause instability. In Drosophila, the nomad retrotransposon efficiently makes DNA but forms extrachromosomal DNA (ecDNA) to protect the genome during spermatogenesis.

More Related Videos

Isolation of Murine Spermatogenic Cells using a Violet-Excited Cell-Permeable DNA Binding Dye
08:21

Isolation of Murine Spermatogenic Cells using a Violet-Excited Cell-Permeable DNA Binding Dye

Published on: January 14, 2021

5.8K
Slide Preparation Method to Preserve Three-dimensional Chromatin Architecture of Testicular Germ Cells
07:34

Slide Preparation Method to Preserve Three-dimensional Chromatin Architecture of Testicular Germ Cells

Published on: January 10, 2014

7.4K

Related Experiment Videos

Last Updated: Jun 16, 2025

Screening Sperm for the Rapid Isolation of Germline Edits in Zebrafish
05:55

Screening Sperm for the Rapid Isolation of Germline Edits in Zebrafish

Published on: February 10, 2023

1.2K
Isolation of Murine Spermatogenic Cells using a Violet-Excited Cell-Permeable DNA Binding Dye
08:21

Isolation of Murine Spermatogenic Cells using a Violet-Excited Cell-Permeable DNA Binding Dye

Published on: January 14, 2021

5.8K
Slide Preparation Method to Preserve Three-dimensional Chromatin Architecture of Testicular Germ Cells
07:34

Slide Preparation Method to Preserve Three-dimensional Chromatin Architecture of Testicular Germ Cells

Published on: January 10, 2014

7.4K

Area of Science:

  • Genetics
  • Molecular Biology
  • Evolutionary Biology

Background:

  • Retrotransposons are mobile genetic elements crucial for genome innovation and evolution.
  • Uncontrolled retrotransposon activity in germ cells can lead to DNA damage, genome instability, and sterility.
  • The mechanisms balancing retrotransposon-driven innovation with germline genome integrity are not fully understood.

Purpose of the Study:

  • To investigate retrotransposon mobilization dynamics in Drosophila spermatogenesis.
  • To understand how germ cells manage retrotransposon activity to maintain genomic stability.

Main Methods:

  • Utilized Drosophila spermatogenesis as a model system.
  • Analyzed retrotransposon mobilization pathways, focusing on LTR-retrotransposon nomad.
  • Quantified DNA synthesis and integration events.

Main Results:

  • The LTR-retrotransposon nomad efficiently completed its mobilization cascade, producing double-stranded DNA (dsDNA).
  • Despite efficient dsDNA production, nomad rarely integrated into the genome.
  • Newly synthesized nomad DNA predominantly formed extrachromosomal circular DNA (ecDNA) during spermatogenesis.

Conclusions:

  • Extrachromosomal DNA (ecDNA) formation serves as a mechanism to sequester retrotransposon-derived DNA in Drosophila germ cells.
  • This sequestration prevents widespread genomic integration, preserving genome stability.
  • The study reveals a strategy for maintaining genome integrity while permitting limited retrotransposon activity.