Coelenterazine chemiluminescence is now established as the most common chemistry responsible for bioluminescence in the sea, being found in seven phyla. However, the organisms which synthesize coelenterazine have yet to be identified. In order to deter-mine whether the luminous midwater shrimp Systellaspis debilis (A. Milne Edwards) (Arthropoda: Decapoda) is capable of luciferin biosynthesis, a developmental series of eggs was assayed for its luciferin, coelenterazine. The advantages of this system are that S. debilis eggs are autonomous and therefore have no external nutrient supply, the embryos can be ranked for developmental stage and the large egg size allows clutch numbers to be determined accurately. Recombinant apo-aequorin, which requires coelenterazine for luminescence, was used to quantify coelenterazine during the developmental sequence. An increase of almost two orders of magnitude was detected in coelenterazine content per egg between the first and final stage of development (mean values of 1 pmol and 71 pmol). This demonstrates de novo biosynthesis of coelenterazine for the first time.
Asymptotic behavior of a nonlinear necrotic tumor model with a periodic external nutrient supply