plasmids: are they always circular?

[SuperSaiyan3]

---

Members don't see this ad.

I tried to look this up on google, and most of them say that plasmids are circular. But my primal microbial instincts say otherwise. Can they also be linear???

 

[matth87]

I tried to look this up on google, and most of them say that plasmids are circular. But my primal microbial instincts say otherwise. Can they also be linear???

I have only heard of plasmids being circular. Since they are located within bacteria and bacteria have circular DNA I can't see why a linear plasmid would exist.

 

[Cunninglinguist]

I tried to look this up on google, and most of them say that plasmids are circular. But my primal microbial instincts say otherwise. Can they also be linear???

They can be linear during transduction and conjugation, but they are usually circular. If you look up gene data for say antibiotic resistance you'll see that you will be looking at genes from a circular plasmid.

I'm not sure if there are other extenuating circumstances where they are not circular, but I would say that 99% of the time they are circular.

 

[SuperSaiyan3]

I have only heard of plasmids being circular. Since they are located within bacteria and bacteria have circular DNA I can't see why a linear plasmid would exist.

bacteria ONLY have circular DNA?

I thought they also had linear DNA!

Apparently I was terribly misinformed.

 

[thebillsfan]

Let's just say that for the MCAT, bacteria have circular DNA

 

[Cunninglinguist]

bacteria ONLY have circular DNA?

I thought they also had linear DNA!

Apparently I was terribly misinformed.

Yeah, man. Bacteria have circular DNA. Even if there are exceptions, you will always want to think circular unless told otherwise, but even then it's probably a trick. Bacterial DNA = Circular.

 

[Hemichordate]

Do bacteria only use rolling circle replication for plasmid transfer?

 

[G1SG2]

Do bacteria only use rolling circle replication for plasmid transfer?

What's "rolling circle replication"? Haha, are you talking about conjugation or am I missing something.