[LMB] teratogenic vs genetic (was News from Lois)

Tora K. Smulders-Srinivasan tks1 at acpub.duke.edu
Wed, 13 Feb 2002 16:51:02 -0500


>At 18:02 02/13/2002 +0100, Bo Johansson wrote:
>>But as Miles often points out, the damage is not genetic, it
>>is teratogenic, i.e. his body was damaged but not his genes,
>>so a clone made from his cells would not inherit the damage.
>pgranzeau at cox.net:
>Those cells would still HAVE the damage, though, would they not?
>Regards, Pete

As a developmental genetics cell biology (or some such combo) grad student, 
let me answer Pete:

         A teratogen is an agent that disrupts the normal development of an 
embryo -- how the cells divide or migrate or differentiate.  (one example 
is retinoic acid -- it will bind to the RAR receptors and tell cells to do 
things at incorrect times compared to normal embryogenesis)

         This does not affect the DNA in the nucleus of the cell -- where 
all the genes reside.

         Thus if cloning happens to a teratogenically disrupted human, the 
genes/DNA/chromosomes will be used, but the agent of disruption is gone, so 
development would occur normally.  (going with previous example, there's no 
retinoic acid in the new environment, so no problem)

         If the chemical agent actually changed the DNA then it would be 
called mutagenic, not teratogenic.

-Tora