[jlgreco]

I suppose what I am suggesting is something along the lines of littering the DNA with lots more "stuff that does nothing" that has a very small edit distance from "encodes the creation of a protein that kills the cell."

So while you might normally have:

  ... ACGATTACGATACG ....
  ---|--------------|---
       |
       useful protein

You would now have:

  ... ACGATTACGATACG TACC TACC TACC TACC TACC TACC TACC TACC TACC ...
  ---|--------------|----|----|----|----|----|----|----|----|----|---
       |                |
       useful protein   pointless proteins

The trick with the TACC being that perhaps TAAC, AACC, and TAGC all, rather than encoding a pointless protein, each encode a protein that will kill the cell. Any random damage to TACC will have a high chance of producing a sequence that will be deadly to the cell.

So each time you get whacked by a gamma ray, you spin a die and see what it hits. Maybe it hits a naturally occurring sequence like 'ACGATTACGATACG' and maybe you get cancer. Or maybe it hits one of those artificially inserted TACC segments that is designed to usually break in such a way that the cell is killed. Add more and more TACC segments and you become less and less efficient, but the odds get stacked more in your favor the more you add.

It would kind of be the "electric fence" approach to arresting unintended behavior (http://en.wikipedia.org/wiki/Electric_Fence).

I suspect actually pulling this off isn't something that is doable in the foreseeable future, since it would require being able to make strong statements of the nature "This segment of DNA should have no effect", and similar, but it makes sense in my head at least ;)