p1: So Lionel, what is your specialty or research area in Biological Sciences?
p1: So I'm a developmental biologist and I'm interested in the relationship between
p1: gene regulation and cell behaviour and development in embryos, and
p1: in my lab, we focus on the development of the lineage that will produce the heart
p1: and the head muscle which we call cardio-pharyngeal uh, for that purpose.
p1: And um, tunicates a great model for that.
p1: Why do you use tunicates as an experimental model and which advantages
p1: do you get by using them as a model?
p1: So we work primarily with Ciona, which is a solitary ascidian
p1: and the niche for using Ciona in my opinion is that on one hand it's a
p1: chordate so it shares features- anatomical developmental features with a vertebrate
p1: for example this cardio-pharyngeal mesoderm this progenitor that makes both heart
p1: and the equivalent of head muscles, which other invertebrates or model organisms
p1: do not have. But Ciona is also very simple, the lineages are fixed,
p1: the genome is simplified and uh extremely tractible.
p1: So it's the combination of the two, it's a simple chordate.
p1: So there's actually an advantage, which appeared to me more recently is that
p1: we work still with wild animals, so um these animals are endowed with all their
p1: robustness mechanisms, they are directly confronted to the environment and so on
p1: and so this may be important in the near future compared to model organisms,
p1: which have been kept in labs for hundreds of generations.
p1: And I think that we're going to see the advantage of this in the near future.
p1: Could you tell us how or why you started working on tunicates?
p1: Yeah absolutely, a so long time ago when I started my PhD in uh '99,
p1: I was really fascinated by this field of Evo Devo -evolutionary developmental biology-
p1: I wanted to track the developmental origin of phenotypic diversity, which fuels evolution
p1: and so I contacted my PhD advisor Jean-Stéphane Joly
p1: and he wanted to start a big evo-devo project, Micro Evo-Devo
p1: using Ciona and I got really excited by the project and that's how I started
p1: working with Ciona in the first place.
p1: Could you tell us a short story on a funny experiment with tunicates?
p1: Yeah, so I mean there are a few anecdotes I can- I could tell you
p1: so one of them, when I was a postdoc in California and we were going in the field
p1: to collect Ciona ourselves in the Half Moon Bay and so
p1: it was really rudimentary, we would just have to lay on the ground and scrape
p1: the bottom of ships and boats and so on.
p1: And uh so we could access only the animals that were close to the surface right?
p1: And one day, someone decided to feed the seagulls with Ciona, which had a really
p1: bad consequence to teach the seagulls that Ciona were edible
p1: and so from that point on the seagulls started scraping the boats clean
p1: and all the easily accessible Ciona were basically gone.
p1: Another anecdote if you will was so in my lab, we were trying to grow Ciona
p1: and so we had um a system of tanks
p1: built by Regis Lasbleiz, who is now in Villefranche-sur-mer
p1: and uh this was working well, we would feed the small juveniles
p1: and they would grow and everybody was happy, including the Ciona
p1: until one day we decided to try and add some adults that came from the wild
p1: and this brought with them uh little crustaceans, copepods,
p1: which then started feasting on the Ciona on the algae, infesting the old system
p1: and turning uh this heaven for tunicates into a literal hell.
p1: OK so the future of tunicate research is necessarily influenced by my own work
p1: in developmental and cell biology and genomics
p1: and uh so one innovation we've been pushing really hard on is um to implement
p1: the development of clean genetic tools because the questions we're having
p1: are more and more precise and we have now tools to measure
p1: phenomena like gene expression, like cell behaviour with a high precision
p1: be it by microscopy, by uh high throughput sequencing,
p1: um but we are still doing rather crude perturbations by transfection of um
p1: wild-type eggs and so on, and so I believe that if we want to be able to ask questions
p1: that will be more and more precise, we need
p1: -and we have the tools to make these measurements!
p1: We need the corresponding clean genetic tools to go along
p1: such as knock-in lines and so on.
p1: And another angle is really harnessing the strength of the tunicates as being
p1: on one hand model organisms that are tractible with which we can do experiments
p1: and on the other they are still wild animals so they live in the ocean and are exposed
p1: to environmental pressures such as um global climate change and so there's really
p1: a unique opportunity to study tunicates and understand um the impact of the real world
p1: on organisms using all the toolkit available for modern biological research.
p1: So that in my opinion is going to be- those two things are going to be a very important
p1: part of the future of tunicate developmental biology or tunicate biology at large.
p1: -And anything about teaching?
p1: Oh yeah for teaching, I mean tunicates are really good because no one knows them
p1: so everybody has something to learn about
p1: them, and they intrigue people in the first place, and so for example
p1: in a graduate course um I had a little lab section where I demoed an electroporation
p1: of Ciona and in the evaluations this was clearly their favorite part, way over
p1: lectures and paper discussions, and then in um undergraduate education they are
p1: very easy to um dissect, work with, make in-vitro fertilization, watch embryos develop
p1: and lava swim around so they're really good to engage people from- at all levels
p1: of education actually.
p1: So the last question is could you say a few words on the tunicate scientific community?
p1: Ah, this community! It's awesome. It's like family. This is where I grew up as
p1: a scientist, I have many friends, I would not miss a tunicate meeting for anything.
p1: Um, and it's been really fascinating to see it grow, to see it- to see new people coming
p1: to see older people stick around, to see young people getting old, including myself
p1: and also to see the progress, the scientific progress, the fact that you know
p1: tunicates are not always recognised outside of the tunicate community and yet
p1: people are pushing, people are improving and what were challenges a few years ago
p1: are now routine experiments and uh, and really rivalling with other models and
p1: I think uh, to people who are not working on tunicates, I would say watch out,
p1: we're coming for you.