We will present you with four different chapters in order to give you an overview of what amphioxus are, why they are interesting animals to answer questions related to the evolution of chordates, and how we manage to use these animals in the lab. First, let’s talk about how scientists discovered amphioxus.




19th century zoologists interested in animal evolution were long fascinated by amphioxus, and there are many old paintings of them, as well as some songs and poems. Amphioxus was later “rediscovered” during the 20th century, and in this chapter we will describe their body plan and how it is achieved through embryonic development and metamorphosis.





Now you know what amphioxus adults and embryos look like, we will talk about other characteristics like its genome and its evolutionary position relative to the other chordate groups, tunicates and vertebrates.





Now you know everything explaining why we are so fond of cephalochordates! Let’s see in this last chapter how we can work with them in the lab.







In this video you will see how we obtain amphioxus embryos of the species Branchiostoma lanceolatum from animals collected in the field.







Immunodetection and fluorescent labelling


In this animation you will see the different steps we will use during the practical course in order to fluorescently label some cellular components in whole amphioxus embryos: axons and cilia, nuclei, and actin filaments. These components are organized differently in different cell types and this labelling will therefore allow us to specifically detect neurons, epidermal cells and muscle cells.