ABSTRACT

In some algae, dormant zygotes are formed as a result of sexual reproduction and show resistance to severe environmental conditions, such as drought. In the case of brown algae, sex pheromones are always involved in successful fertilization (Maier 1993, 1995; Sekimoto 2005). The sex pheromones secreted by immotile female gametes or freshly released eggs induce the chemoattraction or kinetic orientation of the motile male gametes toward female gametes. In some species, pheromones are also responsible for the release of male gametes from the male reproductive organs (antheridia). All of the currently identifi ed pheromones are volatile unsaturated C11 or C8 hydrocarbons. Although several possible mechanisms of action have been proposed, to date, none have been confi rmed (Maier and Müller 1986; Maier and Calenberg 1994). Recently, the 214 million base pair (Mbp) genome sequence for Ectocarpus siliculosus was reported, and the presence of a family of receptor kinases was indicated (Cock et al. 2010). This information has the potential to be useful for identifying a putative pheromone receptor.