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Updated: Jul 13, 2026
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Detection of Horizontal Gene Transfer Mediated by Natural Conjugative Plasmids in E. coli
Published on: March 24, 2023
Complexity, connectivity, and duplicability as barriers to lateral gene transfer
Alon Wellner1, Mor N Lurie, Uri Gophna
1Department of Molecular Microbiology and Biotechnology, George S Wise Faculty of Life Sciences, Tel Aviv University, Tel Aviv, Israel, 69978. alonwell@post.tau.ac.il
Genome Biology
|August 7, 2007
Summary
Lateral gene transfer in prokaryotes is not hindered by protein complexity. Essential genes with high connectivity and low duplicability are typically inherited vertically, not transferred horizontally.
Area of Science:
- Microbial Evolution
- Genetics
- Bioinformatics
Background:
- Lateral gene transfer (LGT) drives microbial evolution and genetic innovation in prokaryotes.
- Protein complexity was hypothesized to impede LGT due to selection pressures against integrating new protein subunits or disrupting existing complexes.
Purpose of the Study:
- To investigate the relationship between protein complex membership, gene connectivity, and gene transfer in prokaryotes.
- To test the hypothesis that protein complexity acts as a barrier to horizontal gene transfer (HGT).
Main Methods:
- Analysis of gene transfer patterns in the model prokaryote Escherichia coli.
- Examination of protein-protein interaction networks and gene duplicability.
- Phylogenetic analysis to assess gene descent patterns.
Main Results:
- Contrary to the complexity hypothesis, membership in protein complexes did not show an inverse correlation with gene transfer.
- Genes with lower involvement in protein-protein interactions outside stable complexes were more frequently transferred.
- Genes with low duplicability demonstrated a reduced likelihood of horizontal transfer.
- Essential genes in E. coli with high connectivity and low duplicability predominantly showed vertical inheritance.
Conclusions:
- Protein complexity and connectivity do not generally impede lateral gene transfer.
- Essential genes with specific characteristics (low duplicability, high connectivity) are preferentially maintained through vertical descent.
Related Concept Videos
01:27Horizontal Gene Transfer
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:...
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.
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.
03:21Genome Size and the Evolution of New Genes
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.
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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.
02:37Gene Duplication and Divergence
The seminal work of Ohno in 1970 popularized the idea of gene duplication and divergence. DNA sequence comparison studies reveal that a large portion of the genes in bacteria, archaebacteria, and eukaryotes was generated by gene duplication and divergence, indicating its critical role in evolution.
The duplicated copies of the gene are called Paralogs. Paralogs with similar sequences and functions form a gene family. Across several species, a large number of gene families are characterized.
The duplicated copies of the gene are called Paralogs. Paralogs with similar sequences and functions form a gene family. Across several species, a large number of gene families are characterized.