- "The lysine contingency is intended to prevent the spread of the animals in case they ever got off the island. Dr. Wu inserted a gene that creates a single faulty enzyme in protein metabolism. The animals can't manufacture the amino acid lysine. Unless they're continually supplied with lysine by us, they'll slip into a coma and die."
- —Ray Arnold(src)
The Lysine Contingency was a genetic alteration Henry Wu performed in the dinosaur genome. The modification knocked out the ability of the dinosaurs to produce the amino acid Lysine. This forced the dinosaurs to depend on lysine supplements provided by the park's veterinary staff. In this way, dinosaurs could never escape from the park because they would never survive long without the food supplements. The Lysine contingency was intended to prevent the dinosaurs from damaging the global ecosystem.
It was also explained that without the Lysine, the animals will collapse into a coma and eventually die. However, it is shown in The Lost World: Jurassic Park and Jurassic Park III that the dinosaurs can survive well without the crew giving them Lysine by eating Lysine rich food, like chickens or soya beans and the carnivores could acquire Lysine by eating herbivores.
In reality, this would be either impossible or useless. None of the vertebrates (or other animal phyla) can produce Lysine, making it an essential amino acid. All animals (including humans) can survive simply by having a lysine rich diet.
Because all known animals lack the ability to produce Lysine, it's unlikely that dinosaurs had. But if they had a pathway for lysine synthesis it would have been like the pathway in plants. Essential enzymes involved in this biosynthesis pathway are:
- β-aspartate semialdehyde dehydrogenase
- Dihydrodipicolinate synthase
- Δ1-piperidine-2,6-dicarboxylate dehydrogenase
- N-succinyl-2-amino-6ketopimelate synthase
- Succinyl diaminopimelate aminotransferase
- Succinyl diaminopimelate desuccinylase
- Diaminopimelate epimerase
- Diaminopimelate decarboxylase.
If Henry Wu wanted to make the dinosaurs Lysine deficient he could have mutated the gene or genes that coded for one of these enzymes.
Jurassic Park: The Game
While the Lysine contingency was barely mentioned in the movies, it plays a major role in Jurassic Park: The Game. Laura Sorkin, another InGen scientist, says that the Lysine Contingency was "cruel and unnecessary", and further calls it "a kill switch" to express her disgust towards Henry Wu's idea. The concept is introduced in the scenario Sorkin's Lab. Dr Sorkin won't leave the island unless she can add Lysine to the water supply of the Parasaurolophus herd. In Water Treatment Sorkin adds Lysine to the main water supply on the island. In this way, all animals will have access to Lysine for a long time. Sorkin and Gerry Harding have constant arguments in the following scenarios about whether this was a wise thing to do.
In Jurassic Park: Operation Genesis the player can add a genetic modification to the dinosaurs to kill them if they break out. But this is a lethal gene. When the player activates this gene the animal dies. This is a more realistic alternative to a Lysine knock-out.
- In Jurassic Park: The Game, in the Back on Track scenario, you can see a post-it note on Dr. Sorkin's monitor showing the formula of Lysine. The note beneath it says "Hammond re supplies late again". This could refer to Lysine supplies.
- The Lysine Contingency might have been inspired by the 1974 novel The Godwhale, where a genetically enhanced warrior is created without the means to synthesize certain amino acids. Instead of nine, like a regular human, he requires fifteen of them in his diet. However, like in the movies, the contingency ultimately fails due to the warrior being given special food with all amino acids present.