Unfortunately the file was heavily damaged by the EMPs caused when the covenant glassed the ONI HQ on Reach. But you did give me something. Apparently, the gene was referred to as UI-GMDNA-34. There was also a brief mention of the covenant working on a biological weapon, but it wasn't very informative. Could be a clue as to what happened though. [spoiler]In other words, I'm completely out of ideas, but I'm definitely saving this for later. [/spoiler]