Asymmetrical jelly secretion of zygotes of Pelvetia and Fucus: An early polarization event.

Five hours before germination the zygotes of Pelvetia fastigiata adhere to their substrate. A jelly layer covers the entire cell but most of the transparent jelly, artificially outlined by a layer of resin beads, is secreted at the prospective rhizoid pole. If the direction of the growth-orienting light is shifted after the asymmetrical secretion has already started, the direction of the secretion is also shifted. The polarization axis can be predicted by the site of the intensive jelly secretion. The germination of Fucus vesiculosus and F. spiralis is also preceded by an intensive asymmetrical jelly secretion. However, at the rhizoid pole of F. serratus the jelly secretion does not increase until the germinating zygote becomes pear-shaped. Fucoid zygotes do not adhere, neither do they have a jelly cover as long as they develop in sulfate-free sea water.