See synopsis:
Original publication:

Variations in the genetic code of life

Photobucket - Video and Image Hosting

The horseshoe crab uses the newly discovered genetic code
(Figure: horseshoe crab lithograph by George Endicott)

“One of the unifying features of life on Earth is that cells almost always use the same genetic language to turn the information in DNA into RNA, then proteins. In a bacterium, a pea or a whale, the same three letters of RNA stand for the same amino acid. UAC, for example, codes for tyrosine.

Some exceptions have been found in the mitochondria of a few organisms, such as nematodes, but now a new method of code-checking has revealed that variant codes also exist in the mitochondria of arthropods – insects and spiders. The finding means that the genetic code, once considered inviolate, might vary more frequently than was thought.”