A couple of articles I've read on ScienceAlert:
An article about the reintroduction of the wild Green Turtle being somewhat a success.
Summary
The green turtle's wild population in the Cayman Islands has been recovered as a result of the reintroduction process; although the wild turtles are presenting a high genetic diversity in the first generation of released turtles in comparison to their parents as a consequence of the captivity process, and they show no difficulties regarding breeding.
Forget ATCG, proteins have been found to use a 'lock and key' system in order to bind to DNA!
Summary
Traditionally, scientists have believed that proteins bind to the DNA by using it a specific combination of the DNA code (made out of ATCG) to lock into place. However it has been found that this is only one vital part of allowing proteins to bind to the DNA- another part is the DNA's 3D shape.