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Updated: Jun 6, 2026
Catheterization of Intestinal Loops in Ruminants
Published on: June 11, 2009
The hidden architects of the genome: a comprehensive review of R-loops
Chetna Yadav1, Ritu Yadav2, Smiti Nanda3
1Department of Genetics, Maharshi Dayanand University, Rohtak, Haryana, 124001, India.
Abstract:
Three-stranded DNA: RNA hybrids known as R-loops form when the non-template DNA strand is displaced and the mRNA transcript anneals to its template strand. Although R-loop formation controls DNA damage response, mitochondrial and genomic transcription, and physiological R-loop formation, imbalanced formation of R-loop can jeopardize a cell's genomic integrity. Transcription regulation and immunoglobulin class switch recombination are two further specialized functions of genomic R-loops. R-loop formation has a dual role in the development of cancer and disturbed R-loop homeostasis as observed in several malignancies. R-loops transcribe at the telomeric and pericentromeric regions, develop in the space between long non-coding RNAs and telomeric repeats, and shield telomeres. In bacteria and archaea, R-loop development is a natural defence mechanism against viruses which also causes DNA degradation. Their emergence in the mammalian genome is controlled, suggesting that they were formed as an inevitable byproduct of RNA transcription but also co-opted for regulatory functions. R-loops may be engaged in cell physiology by regulating gene expression. R-loop biology is probably going to remain a fascinating field of study for a very long time as it offers many avenues for R-loop research.
Insights
R-loops, or three-stranded DNA:RNA hybrids, play critical roles in cellular processes. Imbalanced R-loop formation can disrupt genomic integrity and contribute to diseases like cancer.
Area of Science:
- Molecular Biology
- Genetics
- Biochemistry
Background:
- R-loops are three-stranded DNA:RNA hybrids formed during transcription.
- Their formation is crucial for DNA damage response, transcription, and immune functions.
- Dysregulated R-loop homeostasis is linked to genomic instability and various cancers.
Purpose of the Study:
- To explore the multifaceted roles of R-loops in cellular physiology and disease.
- To understand the regulatory functions and implications of R-loop formation.
- To highlight R-loop biology as a significant area for future research.
Main Methods:
- This study is a review of existing literature on R-loop biology.
- It synthesizes findings from various research areas including molecular biology, genetics, and oncology.
- No new experimental data was generated.
Main Results:
- R-loops are involved in essential cellular processes like transcription regulation and DNA repair.
- They have a dual role in cancer, potentially promoting or protecting against tumorigenesis.
- R-loops are implicated in telomere maintenance and serve as a defense mechanism in prokaryotes.
Conclusions:
- R-loop formation is a tightly regulated process with significant implications for genomic integrity.
- Understanding R-loop biology offers potential therapeutic targets for cancer and other diseases.
- Further research into R-loop dynamics and functions is warranted.
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