Related Experiment Video
Updated: Dec 3, 2025
09:23
Understanding the Impact of Temperate Bacteriophages on Their Lysogens Through Transcriptomics
Published on: January 5, 2024
2.3K
Prevalence of phase variable epigenetic invertons among host-associated bacteria
Xueting Huang1,2, Juanjuan Wang1, Jing Li1
1Department of Basic Medical Science, School of Medicine, Tsinghua University, Beijing 100084, China.
Nucleic Acids Research
|October 29, 2020
Summary
Invertase enzymes drive DNA inversions in bacterial epigenetic invertons, altering gene expression and impacting host adaptation. This epigenetic switching mechanism is widespread in host-associated bacteria.
Area of Science:
- Microbiology
- Genetics
- Molecular Biology
Background:
- Type I restriction-modification (R-M) systems utilize DNA endonuclease and methyltransferase subunits.
- Specific hsdS sequences within R-M systems, termed epigenetic invertons, can undergo DNA inversions catalyzed by invertase enzymes.
- Previous research in *Streptococcus pneumoniae* demonstrated that hsdS inversions lead to significant variations in methylome, physiology, and virulence within bacterial populations.
Purpose of the Study:
- To bioinformatically identify and characterize invertase homologs involved in hsdS inversions across diverse bacterial phyla.
- To investigate the prevalence and function of epigenetic invertons in host-associated bacteria.
- To elucidate the impact of hsdS allelic variations on gene expression and bacterial adaptation.
Main Methods:
- Bioinformatic analysis to identify invertase homologs and their distribution.
- Experimental verification of hsdS inversions in Type I R-M systems of host-associated bacteria.
- Transcriptome analysis to assess gene expression changes due to hsdS allelic variations.
Main Results:
- Six major clades of tyrosine and serine family invertase homologs were identified, suggesting broad potential for hsdS inversions.
- Epigenetic invertons are significantly enriched in bacteria associated with hosts.
- Verified hsdS inversions in four host-associated bacteria, with each allelic variant controlling unique DNA methylation.
- Transcriptome analysis in *Enterococcus faecalis* revealed that hsdS variations substantially affect gene expression.
Conclusions:
- Invertase-driven epigenetic switches within epigenetic invertons are prevalent in host-associated bacteria.
- These epigenetic mechanisms contribute to bacterial host adaptation and virulence, extending beyond their role in R-M systems against phages.
Related Concept Videos
01:16Viral Replication: Lysogenic Cycle
950
The lysogenic cycle is a crucial viral replication strategy that allows bacteriophages to persist within host cells without immediately destroying them. This process is primarily observed in temperate phages, such as bacteriophage lambda (λ), which infects Escherichia coli. The cycle allows the viral genome to persist across bacterial generations while keeping host cells viable.Integration of the Viral GenomeUpon infection, bacteriophage lambda attaches to the bacterial surface and injects...
950
00:46Genomic DNA in Prokaryotes
47.5K
The genome of most prokaryotic organisms consists of double-stranded DNA organized into one circular chromosome in a region of cytoplasm called the nucleoid. The chromosome is tightly wound, or supercoiled, for efficient storage. Prokaryotes also contain other circular pieces of DNA called plasmids. These plasmids are smaller than the chromosome and often carry genes that confer adaptive functions, such as antibiotic resistance.
Genomic Diversity in Bacteria
Although bacterial genomes are much...
Genomic Diversity in Bacteria
Although bacterial genomes are much...
47.5K
02:53Conservative Site-specific Recombination and Phase Variation
6.5K
Because the DNA segments are cut and reorganized in a direction-specific manner, site-specific recombination has emerged as an efficient genetic engineering technique. Flippase and Cyclization recombinases or Flp and Cre, respectively, are two members of the tyrosine recombinase family derived from bacteriophages, that are used to mediate site-specific DNA insertions, deletions, and targeted expression of proteins in mammalian cell lines.
The recognition sites for Cre recombinase called LoxP...
The recognition sites for Cre recombinase called LoxP...
6.5K
01:15Diversity of Protists I
668
Excavata is a diverse group of protists that includes both chemoorganotrophic and phototrophic species, with some thriving in anaerobic environments. Among the key groups within Excavata are diplomonads and parabasalids, which are flagellated protists that lack mitochondria and chloroplasts. These microorganisms typically inhabit anoxic environments, such as the intestines of animals, where they exist either symbiotically or as parasites, relying on fermentation for energy production. Some...
668
00:43Lysogenic Cycle of Bacteriophages
66.3K
In contrast to the lytic cycle, phages infecting bacteria via the lysogenic cycle do not immediately kill their host cell. Instead, they combine their genome with the host genome, allowing the bacteria to replicate the phage DNA along with the bacterial genome. The incorporated copy of the phage genome is called the prophage. Some prophages can re-activate and enter the lytic cycle. This often occurs in response to a perturbation, such as DNA damage, but can also transpire in the absence of...
66.3K
01:26DNA Bacteriophages
500
Bacteriophages, or phages, are viruses that specifically infect bacteria, utilizing their genetic material to hijack host cellular machinery for replication. DNA bacteriophages employ single-stranded DNA (ssDNA) or double-stranded DNA (dsDNA) genomes. These phages exhibit diverse replication strategies and host interactions, influencing their ecological roles and applications in biotechnology and medicine.ssDNA BacteriophagesssDNA phages, with their small genomes, utilize unique strategies to...
500