Brown Algae



Brown Algae



Introduction to the module


Welcome to the module on brown algae. My name is Bénédicte Charrier, I am a permanent CNRS researcher with an initial background in plant biology, and I have been working on brown algae for the past 15 years. I am based at the Marine Biological Station in Roscoff, a town in a region called Brittany in the West of France, which is full of diverse species of algae. My aim is to diversify your knowledge in biology, especially by drawing your attention to brown algae that will hopefully pique your curiosity.

brown algae phylogeny

So, what are brown algae? Brown algae are fascinating organisms: they are eukaryotic and multicellular, like animals and plants, but they evolved completely independently from metazoa and land plants, and even from the other algae, green or red. Because of this distinct evolutionary history, their biology differs.


brown algae size










Secondly, kelp are among the biggest organisms on earth, far taller than land trees (except sequoia trees that are several centuries old!!), and we know virtually nothing about how they grow and develop, compared to what is known in animals and plants.


During this module, we will first study some brown algae basics:  their general cellular and molecular features will lead us to their potential in industry and how they are grown in aquaculture.



brown algae sea

brown algae natural

Then we will focus on these two models:

Ectocarpus, which is a tiny alga as you can see in the Petri dish, and that is currently the model for genomicsand genetic studies...




 ...and Saccharina, 



which in turn is this big seaweed. Despite this obvious difference in size, these two are cousins! So, a very nice lesson given by these brown algae with societal impact is: don’t think that organisms looking different are not closed to each other!

Finally, this module will present you with current research topics on these organisms, which will have you convinced that brown algae are exciting candidates for knowledge breakthroughs!  At the end of my course, you should be able to integrate these brown algae in every question that you will ask yourself about any type of biological process, from evolution to developmental biology, physiology, metabolism, etc. Let’s get started!



Introduction to Seaweed Basics



More knowledge on brown algae biology helps improve the conditions of their cultivation. Some key figures and information about application can be found in the next chapter.




Chapter 1: Applications



 Click here to watch the video


Knowing the evolutionary history of any organism can give perspectives as to how unique they are. The next chapter presents the main milestones of brown algae evolution.





Chapter 2: Evolution




Let’s focus now on two brown algae, current models in academic and applied research. First, I’ll share a few words about some of their general features.





Chapter 3: Meet Ectocarpus and Saccharina



Now that you’ve met the stars of this module, it’s time to dive into lab work!




Chapter 4: How do we study them?

Brown algae in the lab



Now that you’ve seen how we cultivate brown algae, I will present the main downstream resources and techniques that can be used today, in Ectocarpus and Saccharina.


Technical tools to study brown algae



Now that you have seen a palette of technical tools that can be used with these organisms, let’s see what the current hot research topics are for these two brown algae.


Chapter 5: What are the hot topics in research?


Much more remains to be learnt and known about these organisms. You can find additional information in the following references. Hopefully, when you’ll go to the beach, you will now consider these organisms differently.
more informations to see:


Charrier B, Boscq S, Nelson B J, Läubli N F. Growth and immunolocalisation of the brown alga Ectocarpus in a microfluidic environment, BioRXiv




Interactions with the microbiome: the Ectocarpus holobiont


Teacher: Bénédicte Charrier