Plasmid Replication

[90210]

---

Members don't see this ad.

Hi guys,

Let's say we wanted to amplify a particular protein of interest. We take a piece of mRNA from a Eukaryotic Cell. Using Reverse Transcriptase, we transcribe cDNA (double stranded DNA) using the mRNA strand. This cDNA (and an isolated bacterial plasmid) get treated with a restriction endonuclease. Both the cDNA and plasmid get cut at a particular DNA sequence, they are annealed together using Ligase.

So now we have Recombinant DNA (cDNA inserted in the Plasmid). This recombinant plasmid is absorbed by a bacteria via transformation.

Now this is my question: Can this plasmid replicate on its own, producing 100s of plasmids within the same bacteria or does it replicate only when the Bacteria itself replicates. I was sort of confused because I know plasmids also have an origin of replication, so it would make sense to say that the plasmids could replicate within the same bacteria. However, I don't think I ever encountered a situation (or atleast heard of) a situation in which a bacteria had several hundred copies of the same plasmid within it's cell.

 

[90210]

Nevermind, I figured it out.

 

[vayntraubinator]

Nevermind, I figured it out.

Can the plasmid replicate on its own?

I thought it only replicates if it has the F+ plasmid and transfers it over to another bacteria...or if it got integrated into the hose chromosome somehow

 

[BilalL]

Can the plasmid replicate on its own?

I thought it only replicates if it has the F+ plasmid and transfers it over to another bacteria...or if it got integrated into the hose chromosome somehow

If the bacterial cell replicates the extra chromosomal plasmid will also replicate.

Now what the OP was looking at refers to High Copy Number Plasmids and Low Copy Number Plasmids. And this information suggests that certain plasmids based on their origin of replication can frequently replicate in the cell without the cell itself replicating. So one cell may have many copies of a plasmid.

 

[vayntraubinator]

If the bacterial cell replicates the extra chromosomal plasmid will also replicate.

Now what the OP was looking at refers to High Copy Number Plasmids and Low Copy Number Plasmids. And this information suggests that certain plasmids based on their origin of replication can frequently replicate in the cell with the cell itself replicating.

How does origin of replication matter in the copy number of plasmids?? The origin of replication is just one spot on that plasmid from which both directions begin to replicate I thought.


For future reference btw, whats OP?

 

[BilalL]

How does origin of replication matter in the copy number of plasmids?? The origin of replication is just one spot on that plasmid from which both directions begin to replicate I thought.


For future reference btw, whats OP?

Im not an expert on this so I ask you to read this journal article if you wish to understand it better.
http://www.nature.com/embor/journal/v7/n5/full/7400681.html

OP means "original poster" btw 🙂.