ABSTRACT
In this chapter, we compare the development of two brown algae, the tiny filamentous brown alga Ectocarpus sp. and the large parenchymatous brown alga Saccharina latissima. Owing to their major morphological and life cycle differences, broadly described in this chapter, these algae are now two useful models for comparative studies on embryogenesis, juvenile development and reproduction in marine, cell-walled, photosynthetic organisms phylogenetically distant from plants and other multicellular algae. There is abundant literature describing their morphology and histology, and the multitude of available cell biology techniques has recently been supplemented with genomic and tissue- or stage-specific transcriptomic data. The current development of functional approaches involving genetic transformation will further expand this toolbox and make these two species key candidates for addressing fundamental questions on the evolution of embryogenesis, tissue formation and size and shape acquisition during their life cycle. These brown algal models can help shed light on convergent developmental mechanisms shared by other terrestrial and marine multicellular organisms and, more interestingly, on completely novel developmental strategies.
