In this short video, we will present the different parts of the module related to chondrichthyans or cartilaginous fish. Briefly, in this module you will learn why these models are important in experimental biology, which data are available and which experimental approaches are possible. You will also explore several research questions with scientists using chondrichthyan models.






Chapter 1: Chondrichthyans as biological models          


You will see now that chondrichthyans are more specifically at the heart of fields such as Evo-Devo, experimental biology, and molecular phylogeny. Research with these models can also be transdisciplinary. Additionally, in this chapter, you will learn i/ the main species used in research, ii/ the position of cartilaginous fish within the vertebrate phylogenetic tree, and iii/ genomic data available for different chondrichthyan species.








Chapter 2: The life cycle of the catshark



The small-spotted catshark (Scyliorhinus canicula) is one of the most common chondrichthyan model. In this chapter, you will discover it at different stages of its life cycle: embryonic stage, juvenile stage and adult stage.







Chapter 3 : First steps of catshark embryogenesis 


The following animation shows the progression through the first steps of embryogenesis in catsharks (from stage 11 to stage 17).






Sylvie Mazan is a pioneering scientist for using the catshark model in developmental biology. What was her PhD research topic? Why did she decide to switch to Evo-Devo during her career? In this interview, you will discover the profile of a researcher who is fascinated by evolutionary questions.



Interview with Sylvie Mazan (PDF)



Chapter 4: Virtual Lab 



This last chapter is dedicated to practical and functional approaches with catshark embryos and other chondrichthyan species. You will find examples of these approaches that we will have time to discuss during the in-person part of the Schmid Training Course.



Experimental approaches





How to dissect out a catshark embryo




Finally, in the course page on the STC Moodle, you will find a research paper using the catshark model in Evo-Devo studies. In order to help you understand its structure and construction, this paper is entirely annotated. Carefully reading this annotated paper will show you that conducting a research project does not only mean juxtaposing data and experiment results, but requires the authors to construct a complete story and use different experiments to demonstrate their initial hypothesis.




Teacher: Agnès Boutet