Ectocarpus: A Model Organism for the Brown Algae

Abstract

The brown algae are an interesting group of organisms from several points of view. They are the dominant organisms in many coastal ecosystems, where they often form large, underwater forests. They also have an unusual evolutionary history, being members of the stramenopiles, which are very distantly related to well-studied animal and green plant models. As a consequence of this history, brown algae have evolved many novel features, for example in terms of their cell biology and metabolic pathways. They are also one of only a small number of eukaryotic groups to have independently evolved complex multicellularity. Despite these interesting features, the brown algae have remained a relatively poorly studied group. This situation has started to change over the last few years, however, with the emergence of the filamentous brown alga Ectocarpus as a model system that is amenable to the genomic and genetic approaches that have proved to be so powerful in more classical model organisms such as Drosophila and Arabidopsis.

DISTAG/TBCCd1 Is Required for Basal Cell Fate Determination in Ectocarpus

“…After rotating gently to mix, the Petri dish was incubated overnight at 13°C. The following day, 10 mL of culture medium was added (Coelho et al, 2012c) and incubation continued at 13°C. RNAi-induced phenotypes were observed under a light microscope and the number of individuals that resembled the dis mutant were scored in at least 400 individuals for three experimental replicates.…”

“…Duplicate synchronous cultures (with more than 100 individuals each) were prepared for each sample under standard conditions (Coelho et al, 2012c). Upright filaments of adult (4 weeks old) wild-type partheno-sporophytes were dissected from prostrate, basal filaments using the sharp end of a Pasteur pipette under a binocular microscope.…”

“…Recently, the filamentous alga Ectocarpus sp has emerged as a genetic model for the brown algae (Coelho et al, 2012c;Cock et al, 2014). A high-quality genome sequence is available for this species Cormier et al, 2017), together with extensive transcriptomic data Luthringer et al, 2015) and genetic tools including a dense genetic map (Heesch et al, 2010;Avia et al, 2017).…”

“…Ectocarpus has a complex life cycle involving alternation between multicellular sporophyte and gametophyte generations (Coelho et al, 2012c;Peters et al, 2008) (Supplemental Figure 1). Unlike land plants, both the sporophyte and the gametophyte are derived from single cells, which are released into the seawater medium (gametes and meiospores, respectively) greatly facilitating the analysis of early events during development.…”

The Ectocarpus IMMEDIATE UPRIGHT gene encodes a member of a novel family of cysteine-rich proteins with an unusual distribution across the eukaryotes

“…However, the recent emergence of the filamentous alga Ectocarpus sp. as a model organism for this group (Cock et al, 2014;Cock et al, 2015;Coelho et al, 2012a) has created a context in which this type of question can be addressed.…”