Structural analyses of the brown algae Ectocarpus

Abstract text (incl. figure legends and references)

Brown algae belong to the stramenopiles and as such are phylogenetically distant from plants, animals and fungi. They have been evolving independently from plants and animals more than one billion years ago. Brown algae are one of only five eukaryotic lineages that have evolved independently to develop into complex multicellular organisms.

To contribute to the understanding of developmental processes that lead to the observed complex multicellularity in brown algae we have analysed Ectocarpus siliculosus on the ultrastructural level both by scanning and transmission electron microscopy. Several sample preparation techniques were tested to find optimal conditions for structure preservation for this organism. In order to characterise the morphology and ultrastructure of Ectocarpus we have compared the wild-type and a mutant that shows defects in the first cell divisions of the developing organism. Potential differences in Golgi morphology were analysed in datasets obtained by focused-ion beam scanning electron microscopy of plastic embedded samples of both the wild-type and the mutant.