Synaptonemal Complexes in Brown Algae

THE small size of the nuclei of many brown algae makes it difficult to observe the chromosomes and their configurations in nuclear divisions, although life history studies and investigations of nuclei with the light microscope suggest that meiosis in these forms takes place in the unilocular sporangia. One means of testing the validity of this concept is to search for the presence of synaptonemal complexes because the relationship of meiotic chromosomes to these complexes has been well documented1,2and their presence has served as an indicator of meiosis in several members of the Myxomycetes3,4and for several species of red algae5. Our search for such complexes has been successful, and we describe here their occurrence in two species, Chorda tomentosa (Laminariales) and Pylaiella littoralis (Ectocarpales).