Julia L. DESPRAT Home page

Ph.D. in Physiological and Ecology
Working on Eco-toxico-physiology

Personal information
Date of birth: 28 / 06 / 1988
Nationalty: French


Temporary adress
Laboratoire d'éco-physiologie évolutive
Bat D room 311,
Université de Neuchâtel - Institut de biologie
rue Emile-Argand 11
2000 Neuchâtel


2017 Qualification for Lecturer position in Physiology (66), Biology of Populations and Ecology (67) and Biology of Organisms (68) French CNU sections
2012–2015 Ph.D. in physiological ecology, University of Lyon 1
2013 Animal experimentation Degree level 1 necessary to manipulate vertebrate animal species in France, University of Lyon 1
2012 Master of Science Degree in Integrative biology in extreme conditions, University of Lyon 1
2011 Maîtrise of Science in functional, behavioural and evolutionary ecology, University of Rennes 1
2007–2010 Bachelor of Science Degree in physiology and cellular biology, University of Strasbourg
2006 High-school Degree, in sciences with ecology as speciality, agricultural high school of La Côte Saint André.


Research experiences

Current position Post doctorate Researcher (14 months). University of Neuchâtel, Switzerland
Advisor: Dr Fabrice HELFENSTEIN.
Neonicotinoid toxicity on birds behaviour and physiology (Passer domesticus)
2015–2016 Post doctorate Researcher ATER (1 year). LEHNA laboratory, University of Lyon 1, France
Advisor: Dr Nathalie MONDY.
Visual sexual signals as a clue of the health status of Hyla arborea males.
2012–2015 Ph.D. (3 years) LEHNA laboratory, University of Lyon 1, France
Advisor: Dr Nathalie MONDY.
Are steroids mediators of the honesty of male sexual signals in Hyla arborea?
2012 Second MSc Internship (7 months). ECOBIO laboratory, University of Rennes 1, France
Advisor: Dr Emilie LANCE.
Acclimation strategies of exposed gastropods to a biotic or man induced stress.
2011 First MSc Internship (2 months) LEHNA laboratory, University of Lyon 1, France
Advisors: Dr Thierry LENGAGNE and Dr Loïc BREPSON.
Relationships between quality of visual sexual signals and quantity of carotenoids in the food of Hyla arborea males.
2010 Voluntary BSc Internship (2 months). DEPE laboratory, University of Strasbourg, France
Advisors: Dr Yan ROPERT-COUDERT.
Processing of computing data obtained on penguin movements and correlated with reproduction cycle (SPHENOTRON).
And Implementation of a database of Antarctic publications.
2010 Voluntary BSc Internship (2 months). DEPE laboratory, University of Strasbourg, France
Advisors: Dr Jean-Patrice ROBIN.
Lipid dosages and identification as part of a study on digestive physiology in rats.
And Protein dosages on chick penguins muscles.

Current Post-doctoral Position Information

Does pesticide insecticid neonicotinoid affect the behavior and physiology of Passer domesticus?

Laboratoire d'éco-physiologie évolutive
Dommain research: Ecotoxicology, Animal behaviour, Oxidative Stress.

Keywords: bird, cognitive capacity, ecotoxicology, hormone, neonicotinoid

collaborations: Dr Fabrice HELFENSTEIN at the University of Neuchâtel, Switzerland,
Dr Susi JENNI, Ornothological station of Switzerland, Switzerland.

Thesis information

Are steroids mediators of the honesty of male sexual signals in Hyla arborea? PDF [FR]

Laboratory LENHA-UMR 5023 "Ecology of natural and man-impacted hydrosystems"
Physiological ecology, behaviour and conservation team.

Ph.D. defended on the 18th of December 2015 at University of Lyon 1, FRANCE

Supervisors and major collaborators

Jury composition

  • Pr Dominique ALLAINE (President)
  • Pr Michael GREENFIELD (Reviewer)
  • Dr Olivier CHASTEL (Reviewer)
  • Dr Yannick MORET (Examiner)
  • Pr Yann VOITURON (Examiner)
  • Dr Nathalie MONDY (Director)

Scholarships and prizes obtained

2017 - 2018 Post-doctoral funding from the Ornithological station of Switzerland (6201 CHF/months, 14 months)
feb - 2014 Mobility funding from French Research Federation BioEnviSciences (300€)
2012 - 2015 Ph.D. grants from the French Ministry of Higher Education and Research (1646 €/months, 36 months)
2012 Project funding from French Research Federation BioEnviSciences (5000€)

Reviewing activity ( publons.com/a/1544402/ )

2018 Animal Biology
2018 Animal Behaviour
2017 Animal Biology
2017 African journal of herpetology
2016 African journal of herpetology

Research skills

  • Theoretical skills
    • Sexual selection,
    • Signalisation: Acoustic and Visual,
    • Animal behavior,
    • Hormones (steroids),
    • Immunity,
    • Oxydative Stress,
    • Cellular metabolism (mitochondria),
    • Muscular activity.
  • Technical skills
    • Amphibian housing approved (EcoAquatron, University of Lyon 1),
    • Phenotypic engineering (hormonal manipulation),
    • Biochemical dosages: methods of EIA, TBARS, TROLOX, spectrometry, OROBOROS (mitochondrial respiratory metabolism),
    • Electrophysiology on frog muscle,
    • Behavioural study: video traking and acoustic broadcast, spectrometry on integuments,
    • Chromatography HPLC-MSMS: extraction and identification of carotenoids.
  • Field skills
    • Nocturnal capture of amphibians (Hyla arborea and Bufo Bufo)
    • Field acoustic broadcast
    • Natural behavioural observations

Work in progress

  • in prep : Testosterone and bioavailability of carotenoids in the vocal sac of Hyla arborea.
    Desprat J.L., Bellvert F., Lengagne T., Mondy N.


Publications in journals with peer evaluations

Doping for sex: bad for mitochondrial performances? Case of testosterone supplemented Hyla arborea during courtship period.

Desprat J.L., Teulier L., Puijalon S., Romestaing C., Dumet A., Lengagne T., Mondy N.

Comparative Biochemistry and Physiology - Part A: Molecular & Integrative Physiology, 2017, IF= 2.039

Sexual selection has been widely explored from numerous perspectives, including behavior, ecology, and to a lesser extent, energetics. Hormones, and specifically androgens such as testosterone, are known to trigger sexual behaviors. Their effects are therefore of interest during the breeding period. Our work investigates the effect of testosterone on the relationship between cellular bioenergetics and contractile properties of two skeletal muscles involved in sexual selection in tree frogs. Calling and locomotor abilities are considered evidence of good condition in Hyla males, and thus server as proxies for male quality and attractiveness. Therefore, how these behaviors are powered efficiently remains of both physiological and behavioral interest. Most previous research, however, has focused primarily on biomechanics, contractile properties or mitochondrial enzyme activities. Some have tried to establish a relationship between those parameters but to our knowledge, there is no study examining muscle fiber bioenergetics in Hyla arborea. Using chronic testosterone supplementation and through an integrative study combining fiber bioenergetics and contractile properties, we compared sexually dimorphic trunk muscles directly linked to chronic sound production to a hindlimb muscle (i.e. gastrocnemius) that is particularly adapted for explosive movement. As expected, trunk muscle bioenergetics were more affected by testosterone than gastrocnemius muscle. Our study also underlines contrasted energetic capacities between muscles, in line with contractile properties of these two different muscle phenotypes. The discrepancy of both substrate utilization and contractile properties is consistent with the specific role of each muscle and our results are elucidating another integrative example of a muscle force-endurance trade-off.

Immune challenges and visual signaling in tree frogs

Desprat J.L., Lengagne T., Mondy N.

The Science of nature (Naturwissenschaften), 2017, IF= 1.773

In animals, mate-choice is often based on sexual signals that carry information and help the receiver make the best choice to improve the receiver’s fitness. Orange visual sexual signals have been hypothesised to carry immune information because they are often due to carotenoid pigments which are also involved in immunity response. Although many studies have focused on the direct relationships between coloration and immunocompetence, few studies have simultaneously studied immunocompetence response and coloration variation after an immune challenge. We tested this hypothesis on starved and ad libitum fed males of the European tree frog Hyla arborea. Our results show that male coloration is not a reliable indicator of its immune response capacity in this species. However, after an immune challenge induced by a PHA (Phaseolus vulgaris phytohaemagglutinin) injection, starved males presented a significant coloration loss and this alteration was related to the immune response intensity. Taken together, these results suggest that the brighter (lighter) coloration may be used as a cue by female to exclude males with a recent immune challenge, due to diseases or parasites for example.

Does testosterone affect foraging behavior in male frogs?

Desprat J.L., Mondy N., Lengagne T.

Hormones and Behavior, 90: 25-30, 2017, IF= 3.340

During the breeding season, males often produce costly and extravagant displays or physical ornaments to attract females. Numerous studies have established that testosterone could directly influence the expression of certain sexual signals. However, few of these studies have focused on the indirect role that testosterone could play in modulating vigilance and visual performance to improve the foraging ability of males and hence their acquisition of nutritional resource. In the present study, we experimentally modified the testosterone levels of European tree frog males (Hyla arborea), staying in the natural range previously measured in the field, and we investigated the effect of testosterone on the foraging ability of individuals. Foraging capacities were measured on males placed in an arena with a virtual cricket moving on a computer screen. Our results demonstrated a significant effect of testosterone on the hunting behavior of H. arborea. We observed that testosterone reduced the detection latency of virtual prey for supplemented males compared to controls. In addition, testosterone significantly reduced the attack duration of male frogs. Finally, our experiment did not demonstrate any impact of testosterone on male attack success.

Accumulation and detoxication responses of the gastropod Lymnaea stagnalis to single and combined exposures to natural (cyanobacteria) and anthropogenic (the herbicide RoundUp® Flash) stressors.

Lance E., Desprat J.L., Holbech B.F., Gérard C., Bormans M., Lawton L.A., Edwards C., Wiegand C.

Aquatic Toxicology, 177: 116–124, 2016, IF= 3.451

Freshwater gastropods are increasingly exposed to multiple stressors in the field such as the herbicide glyphosate in Roundup formulations and cyanobacterial blooms either producing or not producing microcystins (MCs), potentially leading to interacting effects. Here, the responses of Lymnaea stagnalis to a 21-day exposure to non-MC or MC-producing (33 μg L−1) Planktothrix agardhii alone or in combination with the commercial formulation RoundUp® Flash at a concentration of 1 μg L−1 glyphosate, followed by 14 days of depuration, were studied via i) accumulation of free and bound MCs in tissues, and ii) activities of anti-oxidant (catalase CAT) and biotransformation (glutathione-S-transferase GST) enzymes. During the intoxication, the cyanobacterial exposure induced an early increase of CAT activity, independently of the MC content, probably related to the production of secondary cyanobacterial metabolites. The GST activity was induced by RoundUp® Flash alone or in combination with non MC-producing cyanobacteria, but was inhibited by MC-producing cyanobacteria with or without RoundUp® Flash. Moreover, MC accumulation in L. stagnalis was 3.2 times increased when snails were concomitantly exposed to MC-producing cyanobacteria with RoundUp®, suggesting interacting effects of MCs on biotransformation processes. The potent inhibition of detoxication systems by MCs and RoundUp® Flash was reversible during the depuration, during which CAT and GST activities were significantly higher in snails previously exposed to MC-producing cyanobacteria with or without RoundUp® Flash than in other conditions, probably related to the oxidative stress caused by accumulated MCs remaining in tissues.

Immunocompetence handicap hypothesis in tree frog: trade-off between sexual signals and immunity?

Desprat J.L., Lengagne T., Dumet A., Desouhant E., Mondy N.

Behavioural Ecology, 26 (4): 1138-1146, 2015, IF= 3.157

The immunocompetence handicap hypothesis (ICHH) assumes that testosterone plays a dual role in mediating both sexual signal expression and immunosuppression. Although there is good evidence of the ICHH in birds, it was primarily tested using only one sexual signal approach. By focusing on the European tree frog Hyla arborea, a species for which mate choice is based on both acoustic and visual signals, we test for the rst time the ICHH in a multimodal communication system. The ICHH may be viewed as a universal way to explain signal honesty no matter the sensory modality used by animals. After studying the effects of testosterone on the acoustic and visual sexual signals through a daily testosterone supplementation, the effects of androgen on the immune system response were measured through a phytohaemagglutinin injection. In H. arborea, we demonstrate that both the acoustic and visual sexual sig- nals were testosterone dependent. However, the phytohaemagglutinin injection did not provoke immunosuppression for testosterone-supplemented males. Surprisingly, the testosterone-supplemented males with a high body mass presented an immunoenhancement. Therefore, it seems that ICHH is not an integrating mechanism that is able to explain signal honesty in the multimodal signaling system used by H. arborea in mate choice. On the contrary, our results support the idea that multiple mechanisms (e.g., cost-added and index signals) operating simultaneously may explain signal honesty of both acoustic and visual signals.

A phytohaemaglutinin challenge test to assess immunocompetence of European tree frog Hyla arborea

Josserand R., Troïanowski M., Grolet O., Desprat J.L., Lengagne T., Mondy N.

Amphibia-Reptilia, 36 (2): 111-118, 2015, IF= 1.138

Immune responsiveness, one measure of individual quality, can be used as a sensitive, non-lethal variable that may be negatively affected in animals exposed to degraded, contaminated or otherwise disturbed areas. One frequently used technique to measure immune responsiveness is the phytohaemagglutinin (PHA) challenge test. Swelling occurring at the injection sites are measured before and 24 h after PHA injection. The immune response is considered to be the difference between the two measures. Although this method is easily performed with wild animals, it has been rarely used on small amphibians. Here, we test the possibility of using a PHA test with the European tree frog, Hyla arborea, and we identify the optimal procedure for measuring immune responsiveness in this species. The results allowed us to simplify the procedure in eliminating phosphate-buffered saline (PBS) injection and reducing the duration of the experiment. Injection of PHA into the leg of H. arborea triggered an immune response with a peak of swelling 14 h after injection. A second injection of PHA into the same animal induced more intense leg swelling. In addition, haematological responses showed that the total number of leucocytes increased after PHA injection. A link between the leg swelling and the total leucocytes count recorded in blood has been found. Consequently, this method may provide a useful tool for predicting the pro-inflammatory capacity of field populations of small amphibians.

Other publications

When Ecology and Behaviour meet: Introduction to the special section on the Ecology and Behaviour Meeting 2016

Desprat J.L.

Animal Biology, 66 : 401-402, 2016, IF= 0.617

The current special section of Animal Biology is composed of papers written by participants of the 12th Ecology and Behaviour meeting, held from 27 June until 1 July 2016, in Lyon, France. The Ecology and Behaviour meeting is an annual international congress focussed on ecology, evolutionary biology and behavioural ecology. One thing that is special about this international meeting is that it is fully organised by young researchers working in these fields of science. This year, PhDstudents and post-doctorates of two laboratories from Lyon, France (UMR CNRS 5558 Laboratoire de Biométrie et Biologie Évolutive and UMR CNRS 5023 Laboratoire d’Ecologie des Hydrosystèmes Naturels et Anthropisés) were in charge of the coordination. The second remarkable feature of the Ecology and Behaviour meeting is that it is totally free (participation fees, food and accommodations) for participants. This year, 77 participants from 14 countries have been welcomed to this four-day meeting. Oral presentations were organised around six themes, for each of which two internationally renowned specialists were invited. Hence, all participants benefited from the presence and experience of peers which guaranteed the high quality level of the meeting.

Oral communications and Posters

  • Nov. 2016: Invited seminary at the laboratory of evolutionary ecophysiology, University of Neuchâtel, Switzerland,

    Oral presentation [EN]. Relationships among hormones, coloration and immunity.
    Desprat J.L.

  • 2016: President of the organisation committee of the 12th edition of the international meeting Ecology and Behaviour.

  • Nov. 2015: 2nd French meeting of animal ecophysiology (CEPA), La Rochelle, France,

    Oral presentation [FR]. Testosterone effect on male trunk muscle in Hyla arborea: from acoustic performances to mitochondrial functioning.
    Desprat J.L. , Teulier L.,Puijalon S., Romestaing C., Dumet A., Couchet M., Lengagne T., Mondy N.

  • May 2015: 11th international meeting of Ecology and Behaviour, Toulouse, France,

    Poster [EN]. Testosterone enhances attractive sexual signals but no immunosuppression.
    Desprat J.L. , Lengagne T., Dumet A., Desouhant E., Mondy N.

  • April 2015: French society of animal behaviour (SFECA, French meeting), Strasbourg, France

    Poster [FR]. Sexual signals as a clue for the foraging ability of males in Hyla arborea
    Desprat J.L. , Mondy N., Cheynel L., Rubi G., Lengagne T.

  • Feb. 2014: FR41 BioEnviS, Lyon, France,

    Poster [FR]. Testosterone and carotenoids: are they mediators of the honesty of sexual visual signals?
    Desprat J.L. , Bellvert F. Lengagne T., Dumet A., Mondy N.

  • Nov. 2013: 1st French meeting of animal ecophysiology (CEPA), Lyon, France,

    Oral presentation [FR]. Testing the Immunocompetence handicap hypothesis in Hyla arborea.
    Desprat J.L. , Lengagne T., Dumet A., Rives A., Ducroix L., Mondy N.

    Poster [FR]. Muscular contraction and fatigability properties to explain quality of sexual acoustic signals in males Hyla arborea.
    Desprat J.L. , Teulier L., Dumet A., Couchet M., Puijalon S., Lengagne T., Mondy N.

  • May 2012 :Society of Environmental Toxicology and Chemistry (SETAC), Berlin, Germany

    Poster [EN]. Acclimatization strategies in gastropods to environmental pollutants: comparison of a strong invasive to a declining endogenous species.
    Lance E., Desprat J.L. , Wiegand C.

Teaching activities

ATER Contractual teacher at the University of Lyon 1

2015 – 2016: Teaching duty of 92 hours per year (without tutorial work equivalence)

  • 51h Practical work in Biology of organism; first year of bachelor of biology.
  • 15h Practical work + 6h Tutorial work in Biology of organism; second year of bachelor of biology.
  • 12h Practical work + 1.5h amphitheatre class (osmoregulation) in Physiological ecology; third year of bachelor of physiology and biology.

Teacher assistant at the University of Lyon 1

2012 – 2015: Teaching duty of 64 hours per year

  • 114h Practical work in Biology of organism; first year of bachelor of biology.
  • 12h Practical work in Biology of organism; second year of bachelor of biology.
  • 8h Practical work in Physiological ecology; third year of bachelor of physiology and biology.
  • 58h Tutorial work in Sustainable development; second year of bachelor (all cursus).

Students' supervision


  • Louise Cheynel, in first year of Master CAH, University of Rennes 1.
  • Guillaume Rubi, in first year of Master EcoSystemeS, University of Montpellier 3.


  • Morgane Couchet, in first year of Master CAH, University of Rennes 1.
  • Louise Ducroix, in first year of Master CAH, University of Rennes 1.
  • Albane Rives, in first year of Master EFCE, University of Rennes 1.


  • Learned societies
    • French society of animal behaviour studies (SFECA société française d’étude du comportement animal)
    • French society of ecology (SFE société française d’écologie)
  • Informatics
    • Bibliographic software: Zotero and EndNote
    • Statistical analysis: software R, package « lme4 » and « gglm », parametric and non-parametric tests, ACP, AFC, ANOVA…
  • Language
    • French: native language
    • English: fluent, both written and spoken
  • Sports and Culture
    • Horse riding
    • Hiking
    • Skiing
    • Volley ball
    • Yoga
    • Reading
  • Car and motorbike driving licence