7 minute read
IN CONVERSATION WITH JEHAN-HERVE LIGNOT
ALEX EVANS, IN CONVERSATION WITH... JEHAN-HERVÉ LIGNOT
You never know where a career in biology will take you, as Alex Evans finds out when chatting with JehanHervé Lignot, a professor at the University of Montpellier and convenor of the SEB’s Animal Osmoregulation Group, about his interest in coastal invaders and python intestines.
Below Jehan-Hervé holding a python Photo credit: Stephen M Secor
Hello Jehan-Hervé! Could you please tell me a bit about your career journey so far?
I was brought up in France with the French education system, but when I was a university student, I went to the UK to learn English, spending 2 years in the UK as an Erasmus student at the University of East Anglia (UEA) in Norwich and then as a master’s student at Southampton for 1 year. Then, I had to decide between a PhD in Southampton or a PhD in Montpellier – and I chose the latter mostly because I was more interested in the topic and it gave me the opportunity to work on shrimps in the south of France, but also in Tahiti!
Wow, yes – I can understand the appeal of that!
My first research experience was at UEA; I asked if I could be an intern and they said I could prepare sections for electron microscopy. I spent a month or two with a technician who was really skilled, and he showed me how to prepare the sections and work the microscope, so this was my original interest – looking at mitochondria and membranes in a lab. Then I realised that my colleagues were going on expeditions to incredible environments such as the Antarctic, so I suddenly wanted to get out of the lab! I was then a postdoc for about 4 years across different labs in the UK and the USA, before becoming an assistant professor at the University of Strasbourg in France for 10 years. I actually managed to get my current professorship position here in Montpellier because my former PhD supervisor retired, so I was able to take over from him. He is still an Emeritus professor so I’m still able to see him at the University.
So, you’ve really come full circle. How did you originally get interested in the topic of coastal ecophysiology?
That’s the thing – initially, I didn’t know what I wanted to do. I was interested in biology as an undergraduate and it was in Marseille that I discovered scuba diving. A lot of my teachers were teaching using actual scientific articles, which showed me a whole range of what scientists were publishing and I decided this was something I wanted to explore. My friends at the time said that there’s no jobs and no future in marine biology, so it sounded like I had made a big mistake, but then I learned that one of my teachers was looking for coelacanths, the ‘living fossil’ fish, in the Mozambique channel. I thought, ‘WOW, so that’s what you can do as a marine biologist – let’s go for it!’
And here you are! As I gather, some of your research has looked at how physiological factors like osmoregulation may vary due to environmental changes. What is the value of understanding these things?
My interest in the coast is that it is a fascinating interface between freshwater and seawater. For species to live at such a challenging interface is really interesting to me because they can deal with unpredictable events like salinity changes, major rainfalls or massive droughts. Populations require animals that can deal with rapid and unpredictable environmental changes like this. However, I realised that humans also like to live on the coast, which brings a lot of pollutants directly into water. I thought it would be interesting to see how animals dealt with such extreme environments with the added stress due to anthropogenic pressure – so during my PhD, I became an ecotoxicologist.
Brilliant! What other topics are you researching at the moment?
More recently I’ve been interested in the evolutionary aspect, because with climate change and anthropogenic pressure on the coastal environment, we can see there is a loss in biodiversity but some isolated populations are able to manage better than others. Right now, I’m especially interested in invasive species, because they can adapt very quickly to new environments and there are many species to be found along the coast. There are some aspects of animal behaviour here too, because there is a hypothesis in the literature that bold individuals tend to be the most invasive and are found at the frontlines of invasions.
With your research, do you spend much time working in the field?
It’s not very often now, and I wish it could be more often, but I try to go and sample our study animals myself when I can. Over the last 10 years, I have worked with some French colleagues on a small island called Mayotte in the Mozambique Channel, studying mangrove crabs. They are really interesting because they deal with three interfaces: freshwater, seawater and they’re also able to breathe air so they’re terrestrial animals too. Just before the pandemic started, we were able to spend one month on Europa Island, also in the Mozambique Channel, and we had this fantastic opportunity to work on mangrove crabs there, in a pristine environment with almost no people. Completely isolated with no possible ways to communicate outside.
Just completely cut off – only you and the crabs!
Yes, it was fantastic and I hope that I can do it more often, but it’s good to have a combination now of doing both lab work and fieldwork.
As well as travelling to wonderful places, what have been some of the highlights of your career so far? There are a few scientific stories that I am proud of. For example, when I was working at the University of Strasbourg, I actually switched my research to terrestrial animals and I became interested in the digestive system. We discovered that snakes have a very different system for re-feeding after a prolonged fasting period than rats do.1 In rats, the cells are not able to recover quickly so when food is ready in the stomach for digestion, you get a lot of rapid cell proliferation in the intestine over just a few hours. In snakes, it is very different and this new cell growth occurs right at the end of the digestive process because snakes prepare so well in advance of a re-feed with a batch of new cells that will be ready for the next digested meal, so the two groups of animals have two very different strategies!
Are there any groups of animals that you’ve developed an affinity for working with?
Well, the main problem with aquatic species is that we have a physical barrier between scientists and the animals so they are hard to handle. With terrestrial animals like snakes, you can handle them much more easily without stressing them. I’d never worked with snakes before, so it was really cool to find out they almost treat you like a branch of a tree. The snakes don’t necessarily see us as a threat so you can be close to them without stressing them, which can be much more difficult with fish or birds. And it’s fascinating to see that these animals have so many personalities, some are shy and others are bold, while some are clever and others aren’t.
I was similarly fascinated by this variability in personality in birds during my PhD! What has been your relationship with the SEB so far?
I’ve been a member of the SEB for 26 years, joining when I was a PhD student. They used to run the conferences in the Easter holidays so we could stay in student accommodation! It’s a very good society and I enjoy it very much. I’ve been a longtime member and now I’m a session convenor.
You hosted a session at the SEB conference in Montpellier on coastal adaptation this year.
Yes, and the idea is not just to convene these for myself but also to help promote the work of my younger colleagues. It’s a great way to introduce new members to the society and I hope that it will continue this way. The SEB is a dynamic society and provides a lot of opportunities for people. I think there is only a small community of environmental physiologists, but it’s very diverse. There are not a lot of people working on crustaceans, but I don’t feel isolated because most of the time the research is about major functions such as energetics and mitochondria, so a lot of my career is actually represented.
It’s been a pleasure to talk with you, thank you!
References:
1. Lignot JH. Changes in form and function of the gastrointestinal tract during starvation: from pythons to rats.
In: MD McCue (ed),
Comparative Physiology of Fasting, Starvation, and Food Limitation.
Berlin, Springer, 2012, p. 217–236.
