Transduction, Transfection, Transformation and Infection - (Oct/06/2005 )
We have a little discussion in the lab at the moment - the primary question is - what is the difference between transduction and infection of a target cell? Also if you retrovirally introduce a transgene into a target cell is this considered transduction or infection?
The difference between transformation and transfection we all know
transduction is a mechanism only regarding bacterias that alows them to directly transfer DNA from one to an other one.
Infection is mediated by a foreign agent : basically a virus. this process affects quite all reigns, i mean procaryotes and eucaryotes, no idea about archae... It differs major by the fact it needs at least two restrictions :first, it's an amplification. From one virus, it will be produced quickly millions of viruses. Second, the infection of a cell leads all time to death of the infected cell, which not occurs by transduction.
Hmmm I am not sure this is entirely correct - I think you refer to conjugation when talking about transduction. Transduction in bacteria is via phages, so essentially indirect transfer of genetic material, unlike conjugation, which is direct transfer of DNA via pili (bacterial sex.......)
i would add that infection by a virus (phage or otherwise) does not always result in death of the cell
i'm thinking lysogeny
the way I understand it, when you want to TRANSDUCE DNA into bacteria you can INFECT them with phage that has packaged your GOI
bacteria are frequently TRANSFECTED with phage in the lab, although not every INFECTION results in TRANSFECTION and therefore not all cells which are INFECTED get TRANSDUCED.
infection refers to virus entering cell
transfection refers to viral DNA swapping with chromosomal DNA
transduction refers to the creation of an altered genome using this process
is this right?? am I thinking of this correctly? it is confusing
Transduction refers to the transfer of genomic DNA (chromosomal or plasmid) from the host cell to another cell by virus particles that have erroneously packaged genomic DNA instead of their own.
Thus, RNA viruses can not transduce, because they can not package DNA.
Properly packaged viruses (i.e. carrying their own genetic material) are infectious particles, they cause infections; transducing particles (carrying bacterial genes) do not cause infections. Ester Lederberg (discoverer of this phenomenon) defined transduction to mean the process by which phages transfer bacterial genes.
Transfected originally arose as a term when it was found that DNA purified from phiX174 could be used to infect E. coli by competency transformation. The recipient cells are thus transformed and infected.
I am under the impression that replication-incompetent retroviral vectors that infect a cell and do not propogate a new infection have "transduced" these cells. While retroviruses are RNA viruses, in fact they behave more like DNA viruses. You can "infect" cells with retroviral vectors, but you are "transducing" your gene into these cells.
Okay so this is starting to make a bit more sense! If we are talking about eucaryotic cells, any penetration of the cell membrane by a virus would be considered an infection (i.e. the cell is being infected by the virus). The way you incorporate and the biological state of the virus, is then described by using transduction or (again) infection, meaning that a non-replicative virus is said to Transduce a cell, whereas a replicative virus is said to Infect a cell (or more correctly a host).
Is this more or less correct?
The terms definately seem to be used at random in most major journals (except for journal of virology I guess.....)
huh... sorry need to learn again these items.