Transposons

[Enzymes]

Got this redic question on Kaplan today.

TRANSPOSONS (remember those?) are what cause multi drug resistance in bacteria.

I always associated drug resistance with plasmid genes. Are the transpoons actually contributing to the plasmid? I guess theoretically transposons can jump from genome to plasmid, but I was not aware of that mechanism. Plasmids are not actually FORMED by transposons right? Anyone understand this?

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[Apoplexy__]

Like you said, transposons can serve as an middleman between chromosomal and plasmid DNA. So transposons in a drug-resistant organism can load the genes onto a plasmid that can disseminate to other microbes.

It sounds like it was the type of question where "transposons" was the best answer, but "plasmids" would have been the best overall answer if it were available (was it?).

 

[CherryRedDracul]

It's in FA 2014, p. 128 under "Transposition". Transposons can hop from bacterial chromosomal DNA and plasmid DNA and vice-versa.

 

[Enzymes]

Like you said, transposons can serve as an middleman between chromosomal and plasmid DNA. So transposons in a drug-resistant organism can load the genes onto a plasmid that can disseminate to other microbes.

It sounds like it was the type of question where "transposons" was the best answer, but "plasmids" would have been the best overall answer if it were available (was it?).

Yep, exactly. My main concern was that plasmids are not actually generated by transposons...at least I think. I thought plasmids just got pooped out of the genome by themselves. I realize that many questions are just "what is the best answer" and move on. Just kinda curious though.

 

[Enzymes]

It's in FA 2014, p. 128 under "Transposition". Transposons can hop from bacterial chromosomal DNA and plasmid DNA and vice-versa.

Well, there ya go. Guess it's important! Thanks.

 

[Shadowmoses]

At a basic level of definition, transponsons are jumping genes, while plasmids are small, circular double-stranded DNA molecules not actually a part of the bacterial genome. There are genes on both the bacterial genome and plasmid which can "jump" to the other structure.

I am guessing transponsons do not generate plasmids; rather transponsons are capable of altering the structure of plasmids by incorporating new genetic material into them. Plasmids are like "mobile" DNA which bacteria swap between each other so they can share antibiotic resistances, exotoxins, and other virulence factors. Its kind of like Student Doctor network, where we share our knowledge to help each other out. Bacteria help each other out by exchanging plasmids.

 

[Enzymes]

At a basic level of definition, transponsons are jumping genes, while plasmids are small, circular double-stranded DNA molecules not actually a part of the bacterial genome. There are genes on both the bacterial genome and plasmid which can "jump" to the other structure.

I am guessing transponsons do not generate plasmids; rather transponsons are capable of altering the structure of plasmids by incorporating new genetic material into them. Plasmids are like "mobile" DNA which bacteria swap between each other so they can share antibiotic resistances, exotoxins, and other virulence factors. Its kind of like Student Doctor network, where we share our knowledge to help each other out. Bacteria help each other out by exchanging plasmids.

TEAM PLAYER. You will be a greater doctor, Shadowmoses. I agree with you, thanks!

 

[dyspareunia]

There are also conjugative transposons, which are essentially exactly the same as plasmids.