Spermine is major polyamine in sea urchins: studies of polyamines and their synthesis in developing sea urchins.

Polyamine synthesis and accumulation was studied in several species of developing sea urchins. Most striking is the presence in the gametes of a large amount of spermine, with low amounts of putrescine and spermidine. This contrasts with the pattern of polyamines present in both micro-organisms and mammals. Micro-organisms contain mainly putrescine and spermidine and adult mammalian tissues usually contain equimolar concentrations of spermidine and spermine. During development (i.e. to gastrulation) there is a large increase in the spermidine concentration with relatively little change in either putrescine or spermine levels. After gastrulation, both spermidine and spermine concentrations are elevated. These new accumulations parallel the new synthesis of rRNA that occurs after gastrulation. Enzyme activity patterns parallel the changes detected in the concentrations of the polyamines with the exception of ornithine decarboxylase activity. This exception may be due to the rapid turnover of putrescine, the precursor for the synthesis of spermidine and spermine.