SDN members see fewer ads and full resolution images. Join our non-profit community!


Discussion in 'Step I' started by Enzymes, May 17, 2014.

  1. Enzymes

    Enzymes 2+ Year Member

    Mar 13, 2012
    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?
  2. SDN Members don't see this ad. About the ads.
  3. Apoplexy__

    Apoplexy__ Blood-and-thunder appearance 5+ Year Member

    Oct 20, 2012
    Up on the Hydra's back
    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?).
    shigella123 likes this.
  4. CherryRedDracul

    CherryRedDracul Resident Sh!tposter Physician 5+ Year Member

    Oct 12, 2012
    North America
    It's in FA 2014, p. 128 under "Transposition". Transposons can hop from bacterial chromosomal DNA and plasmid DNA and vice-versa.
    Enzymes likes this.
  5. Enzymes

    Enzymes 2+ Year Member

    Mar 13, 2012
    Yep, exactly. My main concern was that plasmids are not actually generated by 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.
  6. Enzymes

    Enzymes 2+ Year Member

    Mar 13, 2012
    Well, there ya go. Guess it's important! Thanks.
  7. Shadowmoses

    Shadowmoses 5+ Year Member

    Mar 18, 2011
    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.
    DeeJay2728 likes this.
  8. Enzymes

    Enzymes 2+ Year Member

    Mar 13, 2012
    TEAM PLAYER. You will be a greater doctor, Shadowmoses. I agree with you, thanks!
    Shadowmoses likes this.
  9. dyspareunia


    Mar 6, 2014
    There are also conjugative transposons, which are essentially exactly the same as plasmids.

Share This Page