ULTRASTRUCTURE OF MALE GAMETOGENESIS IN FUCUS-SERRATUS (PHAEOPHYCEAE)

The main structural features of male gametogenesis in Fucus serratus L. are described. The antheridial parent cells exhibit meristematic characteristics: large nucleus, dense cytoplasm, chloroplasts with few thylakoids. Synaptonemal complexes are frequently observed in the nuclei at the same time that microtubules are very abundant around the centrioles. Meiotic spindles are intranuclear, as are the mitotic spindles of the subsequent synchronous karyokineses. A nuclear membrane is present in all stages observed. Antheridial maturation is accompanied by multiplication of mitochondria and plastids as well as development of two major kinds of “vacuoles.” Cytokinesis proceeds with the progressive fusion of one of these types of vacuoles: this mode of cytoplasmic cleavage is unique among algae. Formation and differentiation of characteristic spermatozoid organelles (flagella, eyespot, proboscis) are also described. Copyright © 1979, Wiley Blackwell. All rights reserved