Quantitative Evaluation of Erotactin Secretion in Eggs of Hormosira banksii (Fucales,Phaeophyceae)

The release of the C₁₁-hydrocarbon spermatozoid attractant hormosirene by eggs of the Australian fucoid Hormosira banksii has been determined quantitatively using a closed-loop extraction technique. The eggs secrete erotactin for more than 2 weeks with an exponentially decreasing rate. The initial secretion rate was estimated to be 75 fmol h^?1 egg^?1 and the total amount of hormosirene produced per egg to be 2.35 pmol (0.35 ng). The results were used to calculate the threshold range for spermatozoid chemotaxis in the pheromone gradient around eggs.