Related Experiment Video
Updated: Jun 22, 2026
06:09
Generation of Monoclonal Cultures from Wolbachia-infected Drosophila melanogaster JW18 Cell Line
Published on: June 27, 2025
Conservation of the Type IV secretion system throughout Wolbachia evolution
Samuel Pichon1, Didier Bouchon, Richard Cordaux
1Université de Poitiers, UMR CNRS 6556 Ecologie, Evolution, Symbiose, 40 avenue du Recteur Pineau, F-86022 Poitiers, France.
Biochemical and Biophysical Research Communications
|June 3, 2009
Summary
The Type IV Secretion System (T4SS) genes are highly conserved across Wolbachia strains, indicating their crucial role in bacterial survival. Variations in flanking regions suggest flexible genomic integration of the T4SS.
Area of Science:
- Microbiology
- Genetics
- Molecular Biology
Background:
- The Type IV Secretion System (T4SS) facilitates bacterial DNA and protein transfer to eukaryotic cells.
- Wolbachia pipientis, an endosymbiont, utilizes T4SS for interaction with host cells.
- Previous studies identified two vir gene operons encoding T4SS in Wolbachia.
Purpose of the Study:
- To investigate the conservation and genomic organization of T4SS vir genes in Wolbachia.
- To correlate T4SS gene structure with diverse Wolbachia-induced host phenotypes.
Main Methods:
- Comparative genomic analysis of T4SS vir genes across 37 Wolbachia strains.
- Examination of genomic sequences flanking the virB8-D4 operon.
Main Results:
- Strict conservation of virB3-B6 and virB8-D4 operon sequence and organization was observed across all studied Wolbachia strains.
- Extensive variation in genomic regions adjacent to the virB8-D4 operon was identified, indicating diverse integration sites.
- T4SS gene conservation was consistent across strains exhibiting phenotypes like cytoplasmic incompatibility and feminization.
Conclusions:
- The T4SS is a long-term conserved system in Wolbachia, essential for its biology and host cell survival.
- The flexible genomic location of the virB8-D4 operon suggests adaptive mechanisms for T4SS integration.
- Functional effector translocation via T4SS is likely critical for Wolbachia's endosymbiotic lifestyle.
Related Concept Videos
01:16Transduction
Among the three main modes of HGT—transformation, conjugation, and transduction—transduction is unique in that it is mediated by bacteriophages, or bacterial viruses.Transduction occurs in two ways. Generalized transduction occurs during the lytic cycle of a bacteriophage infection. In this process, bacteriophages infect bacterial cells, replicate within them, and ultimately cause cell lysis, releasing newly assembled virions. Occasionally, random fragments of the bacterial genome are...
01:17Gram-negative Bacterial Protein Secretion Systems
Gram-negative bacteria utilize sophisticated protein secretion systems to transport proteins across their double-membrane envelope into the extracellular environment or host cells. Based on their mechanism of action, these systems are classified into one-step and two-step pathways.One-Step Secretion Systems (Types I, III, IV, and VI)One-step secretion systems bypass the periplasm entirely, forming a continuous channel that spans both the inner and outer membranes:Type I Secretion System (T1SS):...
01:24Evolution of New Traits in Microbes
Microorganisms evolve rapidly due to their large population sizes and short generation times, often exhibiting measurable changes within days under laboratory conditions. Natural selection acts on standing genetic variation, enabling the retention and amplification of beneficial traits that confer fitness advantages in changing environments.Adaptive Pigment Regulation in RhodobacterIn Rhodobacter, a genus of purple non-sulfur bacteria, light-harvesting pigments such as bacteriochlorophyll and...
01:28Regulation of Bacterial Virulence
Pathogenic bacteria employ a range of regulatory mechanisms to modulate the expression of virulence genes in response to environmental and host-derived signals. These mechanisms ensure that virulence factors are expressed only under favorable conditions, thereby optimizing infection and survival strategies.Mechanisms of Virulence RegulationKey regulatory strategies include:Two-Component Systems: These consist of a membrane-bound sensor kinase and a cytoplasmic response regulator. Environmental...
01:16Viral Replication: Lysogenic Cycle
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 its...
02:18Types of Genetic Transfer Between Organisms
Genetic transfer occurs when genetic information is passed from one organism to another. It occurs via two mechanisms: vertical gene transfer and horizontal gene transfer. Vertical gene transfer occurs when genetic information is transferred from one generation to the next, which happens much more frequently than horizontal gene transfer. Both sexual and asexual reproduction are forms of vertical gene transfer, where one or more organisms pass some or all of their genome onto their progeny.