Simple question that is hard to answer
(by pjie2 from cam.ac.uk)
Fri Feb 16 15:27:14 EST 2007
> Your input is always appreciated, just my question was different and I
> don't know how better to describe - can one have two alleles of the
> SAME Plasmid in the SAME cell, not different ori, not different
> antibiotic resistances, everything is the same, just point muataion
> that comes from cloning of heteroduplex DNA that has a mutation.
It would seem unlikely. Even assuming the heteroduplex molecule got cloned
in the first place, my suspicion is that the first time it gets replicated,
the mismatch would be "corrected" and you'd get two identical daughter
copies of one allele or the other.
Conversely, assuming you're transforming a mixed population of alleles in
the first place, it's very unlikely that you'll get both alleles in the same
bacterium - the whole *point* of the transformation is that you only get one
plasmid into any given bacterium.
You might end up with a heterogeneous population of plasmids inside the same
bacterium, but that'll only happen if it's (a) a high copy number plasmid
and (b) acquired the mutation within the bacterium.
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