Related Experiment Video
Updated: Nov 7, 2025
04:56
Author Spotlight: Advancements in Understanding and Combatting Shigella Infections
Published on: February 9, 2024
1.2K
High Rates of Genome Rearrangements and Pathogenicity of Shigella spp
Zaira Seferbekova1,2, Alexey Zabelkin3,4,5, Yulia Yakovleva5,6
1Faculty of Bioengineering and Bioinformatics, Lomonosov Moscow State University, Moscow, Russia.
Frontiers in Microbiology
|April 29, 2021
Summary
Shigella bacteria exhibit high genomic rearrangement rates, driven by insertion sequences, distinguishing them from E. coli. This genomic plasticity is key to their evolution as intracellular pathogens.
Area of Science:
- Microbiology
- Genomics
- Evolutionary Biology
Background:
- Shigella, a pathogen within the Escherichia lineage, is often classified separately due to distinct genomic features.
- Insertion sequences (ISs) in Shigella genomes contribute to gene pseudogenization and increased non-homologous recombination.
Purpose of the Study:
- To investigate the role of genomic rearrangements in Shigella evolution.
- To compare rearrangement rates between Shigella and Escherichia coli strains.
- To identify genetic elements contributing to Shigella's pathogenic evolution.
Main Methods:
- Comparative genomics analysis of 414 E. coli and Shigella genomes.
- Assessment of intragenomic rearrangement rates and homologous recombination.
- Identification and analysis of specific gene families, including E3 ubiquitin-protein ligases.
Main Results:
- Shigella strains show significantly higher rates of genomic rearrangement compared to pathogenic and non-pathogenic E. coli.
- Homologous recombination rates are decreased in Shigella.
- Two conserved E3 ubiquitin-protein ligases were identified in all Shigella strains, absent in enteroinvasive E. coli (EIEC).
Conclusions:
- Genomic rearrangements, influenced by IS accumulation, are crucial for Shigella's evolution as intracellular pathogens.
- Non-coding regions and specific gene acquisitions play a significant role in the evolution of pathogenic genomic islands.
- Comparative genomics reveals distinct evolutionary trajectories shaped by genomic instability.
Related Concept Videos
00:57Viral Recombination
24.2K
Cells are sometimes infected by more than one virus at once. When two viruses disassemble to expose their genomes for replication in the same cell, similar regions of their genomes can pair together and exchange sequences in a process called recombination. Alternatively, viruses with segmented genomes can swap segments in a process called reassortment.
24.2K
01:15Diversity of Protists I
595
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...
595
01:20Mismatch Repair
5.6K
Organisms are capable of detecting and fixing nucleotide mismatches that occur during DNA replication. This sophisticated process requires identifying the new strand and replacing the erroneous bases with correct nucleotides. Mismatch repair is coordinated by many proteins in both prokaryotes and eukaryotes.
The Mutator Protein Family Plays a Key Role in DNA Mismatch Repair
The human genome has more than 3 billion base pairs of DNA per cell. Prior to cell division, that vast amount of genetic...
The Mutator Protein Family Plays a Key Role in DNA Mismatch Repair
The human genome has more than 3 billion base pairs of DNA per cell. Prior to cell division, that vast amount of genetic...
5.6K
02:32Exon Recombination
3.8K
The evolution of new genes is critical for speciation. Exon recombination, also known as exon shuffling or domain shuffling, is an important means of new gene formation. It is observed across vertebrates, invertebrates, and in some plants such as potatoes and sunflowers. During exon recombination, exons from the same or different genes recombine and produce new exon-intron combinations, which might evolve into new genes.
Exon shuffling follows “splice frame rules.” Each exon...
Exon shuffling follows “splice frame rules.” Each exon...
3.8K
01:18Mutations in Microorganisms
228
Mutations are heritable changes in an organism’s genome involving alterations in the base sequence of DNA or RNA. These changes can influence cellular processes and phenotypic traits, potentially transforming the unaltered wild type into a mutant form. Such changes, termed forward mutations, are pivotal in shaping the genetic diversity of organisms.RNA viruses exhibit the highest mutation rates due to the absence of robust proofreading mechanisms during genome replication. In contrast,...
228