Expert: Florence M Rollwagen - 9/29/2008

Question
QUESTION: Hello sir..
        I want to ask you a question that is disturbing me alot..Recently we studied in our biology class that in bacteria, there is a mode of reproduction called transduction in which genetic material is transferred from one bacteria to another by virus, which destroys first bacterial cell but it doesn't harm second bacterial cell because in that cell its genetic material is not dominant.. but m confused that same should happen in human cells but it doesn't happen and it destroys all the cells in human body.. why is that so?
      I hope I m clear about my question because my teacher didn't understand my question..And thankew so so so so much i'll be realy grateful to you..Thanks alot..

ANSWER: Hi Pooja:  I don't understand exactly what you're asking, so let me try to clarify and you can get back to me on what the actual question is.

When you say "same should happen in human cells"  

1.  Do you mean that human cells can exchange genetic information?
2.  Do you mean that viruses can transfer genetic information between human cells?  
3.  Do you mean that viruses can transfer genetic information between bacteria and human cells?
4.  Do you mean that viruses can transfer their own (viral) genes into human cells?

Help me out here, what are you really asking?

FMR

---------- FOLLOW-UP ----------

QUESTION: Sir i mean to say that during transduction viral cell attacks one bacterium, replicate in it, then destroys it and after that, its replicated copies attack any other bacterium, but they don't destroy it and just transfer the genetic material of the destroyed bacterium and replicate in it... on the other hand in human cells they replicate in one cell, destroy it, then attack other cells but destroy it also in this way they attack all the cells of the body, like HIV...Sir I'm really very sorry that am not able to convey my question clearly and I really appreciate ur time and knowledge... Thankew so much..

Answer
Hi Pooja:  I think I know what you're asking.  You've confused "lytic cycle" with "lysogenic cycle" in transducting bacteria.  So look up those two terms and see if it helps your understanding.

Second, bacteriophages (viruses that attack bacteria) don't enter the bacterial cell.  They just inject their DNA, which then codes for the replication of the phage particle.

Animal viruses (like HIV) completely enter the cell.  There they use the host's cellular machinery to replicate more virus particles.

Look up this information and then ask a more coherent question.

FM Rollwagen, PhD