The newly sequenced genome of the brown seaweed Ectocarpus siliculosus sheds light on how this complex photosynthetic organism has adapted to life on rocky shores. A study by international consortium of scientists led by the Station Biologique de Roscoff in Brittany, France appears in the most recent issue of Nature. The paper is titled 'The Ectocarpus genome and the independent evolution of multicellularity in the brown algae.'
Genomic analysis of the brown algae reveals an extended set of light-harvesting and pigment biosynthesis genes, and novel metabolic processes such as halide metabolism - features that may help to explain how the seaweed copes with the highly variable tidal environment.
The brown algae, which are only distantly related to green plants, are one of only a small number of eukaryotic lineages to have evolved complex multicellularity.
Analysis of the Ectocarpus genome indicated that the emergence of a family of membrane-localised receptor kinases may have played an important role in the transition to a multicellular lifestyle. This is a remarkable observation because related membrane-localised receptor kinase families evolved independently in both animals and green plants and in both cases have been linked with the emergence of multicellularity in these groups.
The Ectocarpus genome project is just the first step of a program aimed at understanding seaweed developmental biology, work that will not only improve our understanding of coastal ecosystems such as the beautiful undersea kelp forests but may also provide insights into our own origins on this planet.