Skip to content
Change & defence

HHorizontal gene transfer

Sideways DNA traffic — conjugation, transduction, transformation as names and history, not protocols.

Also called: Lateral gene transfer ? Mobile DNA

Diagram of DNA moving between bacterial cells
Andrew Z. Colvin ? CC BY-SA 4.0

Quick facts

Fred Griffith showed that a 'transforming principle' from heat-killed smooth pneumococci could change live rough cells in mice — history, not a protocol.Griffith 1928
Avery, MacLeod and McCarty identified the transforming principle as DNA, a foundation of molecular biology.Avery 1944
Lederberg and Tatum showed E. coli can exchange genes by direct contact — conjugation in the textbook sense.Conjugation 1946
Zinder and Lederberg found phages can ferry bacterial genes between cells.Transduction 1952
Beta-lactamase and other cassettes ride plasmids and integrons across species — why stewardship is ecological.Resistance hitchhikers
Transformation, conjugation and transduction are the named routes. This page stays at names and history, not lab steps.Three textbook routes

Horizontal gene transfer is sideways inheritance: DNA moves between contemporaries instead of only from parent to offspring.

That is why resistance genes can jump species in hospitals and farms. The public story is traffic, not a construction kit.

Transformation, conjugation and transduction are names for different vehicles. None of them is written here as a protocol.

The profile

455525508240
  • Familiarity45
  • Medical weight55
  • Benefit25
  • Risk50
  • Research82
  • Live debate40

Risk

50 / 100

Sideways DNA traffic — conjugation, transduction, transformation as names and history, not protocols.

Seven ways into this topic

Frequently asked questions

Is HGT the same as sexual reproduction?
No. Bacteria do not do meiosis. They can still move DNA sideways between contemporaries.
Why does resistance spread so fast?
A successful plasmid can enter a new species without waiting for the same mutation to arise again.
Do humans do HGT?
Our species evolves mainly by vertical inheritance. Some viral inserts sit in genomes as ancient history, not a method.
What is a plasmid?
An optional extra DNA circle (or linear piece) that can carry extra jobs such as resistance or extra metabolism.
Is transformation something I can do in a kitchen?
This atlas will not provide methods. Griffith's mice are a 1928 story, not a hobby.
Do all bacteria take up DNA from the environment?
Competence is regulated and species-specific. Many never do it under ordinary conditions.
Is CRISPR a form of HGT?
CRISPR systems record past phage encounters. They are immune memory in bacteria, not a how-to for editing pathogens here.
Is this medical advice?
No. Educational only. Infection treatment stays with licensed clinicians.

Sources & research

  1. Horizontal gene transfer2026 · Wikipedia
  2. Griffith's experiment2026 · Wikipedia

Media credits

More in Change & defence