Related Experiment Video
Updated: Aug 26, 2025
06:56
Detection of Horizontal Gene Transfer Mediated by Natural Conjugative Plasmids in E. coli
Published on: March 24, 2023
5.7K
The Role of the Environment in Horizontal Gene Transfer
Hande Acar Kirit1,2,3, Jonathan P Bollback1, Mato Lagator4
1Veterinary and Ecological Sciences, Institute of Infection, University of Liverpool, Liverpool, Merseyside, United Kingdom.
Molecular Biology and Evolution
|October 13, 2022
Summary
Environmental conditions unpredictably impact gene fitness effects during horizontal gene transfer. However, the distribution of these fitness effects across genes remains consistent, revealing generalizable patterns in gene transfer.
Area of Science:
- Microbiology
- Evolutionary Biology
- Genetics
Background:
- Gene-by-environment interactions are critical for horizontal gene transfer (HGT), influencing how transferred genes affect host fitness.
- Previous research has not systematically investigated how environmental factors modulate the fitness consequences of HGT.
- Understanding these interactions is key to predicting the evolutionary trajectory of microbial communities.
Purpose of the Study:
- To experimentally quantify the fitness effects of transferred genes across diverse environmental conditions.
- To determine if the distribution of fitness effects varies significantly between environments.
- To explore the relationship between a gene's average fitness effect and its environmental variability.
Main Methods:
- Utilized a high-throughput technique for precise bacterial fitness estimation.
- Measured the fitness effects of 44 orthologous genes transferred from Salmonella Typhimurium to Escherichia coli.
- Tested these effects across six distinct, physiologically relevant environments.
Main Results:
- Individual gene fitness effects were highly environment-dependent.
- The overall distribution of fitness effects across all tested genes was consistent across environments.
- Genes with extreme average fitness effects (nearly neutral or lethal) showed more consistent effects across environments than deleterious genes.
Conclusions:
- Environmental conditions introduce unpredictability in the fitness impact of individual transferred genes.
- Despite individual variability, the distribution of fitness effects across genes exhibits consistent patterns, suggesting generalizable principles in HGT.
- These findings highlight the complex interplay between genes, environment, and bacterial evolution.
Related Concept Videos
01:27Horizontal Gene Transfer
78
Horizontal gene transfer (HGT) is a process where genetic material moves between organisms within the same generation, unlike vertical gene transfer, which occurs from parent to offspring. HGT plays a crucial role in microbial evolution, adaptation, and survival, particularly in shared environments like the human gut.Mobile genetic elements such as plasmids, prophages, integrons, insertion sequences, and transposons facilitate this process. HGT occurs through three primary mechanisms:...
78
02:18Types of Genetic Transfer Between Organisms
29.1K
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.
29.1K
01:16Transduction
79
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...
79
01:19Conjugation
59
Conjugation is a form of horizontal gene transfer that primarily occurs in bacteria and some archaea, promoting genetic diversity and adaptation. Bacteria can acquire resistance genes through conjugative plasmids, allowing them to survive antibiotic treatments that would otherwise be lethal. This process involves direct contact between cells through specialized structures such as the sex pilus and is mediated by conjugative plasmids, including the F (fertility) factor.Conjugation requires...
59
03:21Genome Size and the Evolution of New Genes
8.1K
While every living organism has a genome of some kind (be it RNA, or DNA), there is considerable variation in the sizes of these blueprints. One major factor that impacts genome size is whether the organism is prokaryotic or eukaryotic. In prokaryotes, the genome contains little to no non-coding sequence, such that genes are tightly clustered in groups or operons sequentially along the chromosome. Conversely, the genes in eukaryotes are punctuated by long stretches of non-coding sequence.
8.1K
01:19Mechanism of Conjugation
95
Bacterial conjugation is a mechanism of horizontal gene transfer that enables the exchange of genetic material between bacterial cells through direct contact. This process is facilitated by a donor cell carrying a conjugative plasmid, which encodes genes necessary for pilus formation, DNA replication, and transfer. The conjugative plasmid plays a central role in initiating and executing the transfer of genetic material.The tra region of the conjugative plasmid encodes proteins responsible for...
95