EXPERIMENTAL INVESTIGATIONS

The model system consisting of Drosophila and parasitic wasps was chosen because it was well suited for studies on development of resistance in hosts and development of virulence (protection) of parasitoids at the molecular, genetical and populational levels. Here is the immune reaction of Drosophila larvae against parasitoid eggs :



The genetic mechanism of resistance of D. melanogaster is based on a monogenic dominant system. This resistant character is inherited autosomally, suggesting a single major segregating locus with two alleles (resistance and susceptibility). This system is highly specific and 2 genes of resistance are now localized (Rlb and Rat against L. boulardi and Asobara tabida, respectively) on the right arm of the second chromosome. We also demonstrated with the parasitic wasp Leptopilina boulardi that all the genetic components of virulence variation are comprised in a single segregating factor integrated to the wasp chromosome (as a "gene"). Two genetic systems of virulence have been detected (Ism and ISy), each against a host species, D. melanogaster and D. yakuba respectively. Encapsulation of wasp egg by its host appears to be governed by major genes in the host and in the parasitoid populations. The gene for resistance against L. boulardi in the host is counteracted by a gene for virulence against D. melanogaster immune system in the parasitoid population. Species specificity of these genes have been shown both for the host and the parasitoid, according to a "gene-for-species" model. From an evolutionnary point of view, local adaptations of the immune suppressive genes toward the host species present in the locality were detected.

These investigations of the biochemical and genetic aspects of the Drosophila-parasitoid relationships successfully developed in part from fruitful cooperations with Professor A. Nappi (Loyola University, Chicago) and Professor Marylene Poirié (Nice University, INRA, Sophia Antipolis).Since 2008 our collaborative efforts have produced 5 published reviews in various journals concerning co-evolutionary processes, specially "The Advances in Parasitology".




HISTORICAL ASPECTS of BIOLOGICAL SCIENCES
In addition, I have been also interested in the historical development of entomology and entomologists, especially of Reaumur (1683-1757) and Buffon (1707-1788), and various aspects of the scientific cooperation between French and American entomologists during the period 1830-1940.

Perhaps one of the most successful cooperations between these two groups was Professor Charles Valentine Riley (1843-1895), the famous American entomologist who saved French vineyards from attack by the louse Phylloxera by introducing American resistant Vitis species in France. It has been certainly a model scientific cooperation between the countries.

   

visit also these websites :
https://www.bordeaux-aquitaine.inra.fr/bordeauxaquitaine/toute_l_actu/conference_phylloxera_29_06_2010
http://www.paysud.com/Comment-un-entomologiste-americain-a-contribue-a-sauver-la-vigne-francaise_a817.html



More recently, I discovered in the Riley's archives (National Agricultural Library, Beltsville, MD, USA) the dedicated photograph of his French colleague friend, H. de Varigny (1855-1934) who had chosen to introduce the Darwinian theory to the French people. I recounted this relationship in my book published in 2009 dealing with the scientific life of H. de Varigny and his efforts to introduce these new evolutionary concepts in France despite the hostility of French biologists to Darwinian principals, an hostility that delayed by 8 years the election of Darwin to the French Academy of Sciences !



Press review:
http://www.editions-hermann.fr/voirRevue.php?revueid=2562&menu=6&prodid=657〈=fr

BIBLIOTHEQUE NATIONALE DE FRANCE, "Les rendez-vous du samedi", site François-Mitterrand, free access. The french national library organize each week (on saturday afternoon, 17h-18h pm) an appointment with some well-known persons such as authors, movie producers, scientists, artists, whom production has retained attention.
Saturday, 23 may 2009, 17h - 18h : Yves Carton "accueil et diffusion du darwinisme en France" Yves Carton is the guest of this new appointment for his book : " Henry de Varigny, darwinien convaincu, médecin, chercheur et journaliste (1855-1934) " published by Hermann editor. Hervé Colinmaire, director of the department "Sciences et techniques de la BnF", with hte collaboration of Jérôme Petit, responsible of the science history collections, will animate this meeting. Darwinian theory concerning species evolution has been more or less well understood in France, with a hostile reception by the french biologistes. Henry de Varigny, physician and PhD, researcher, will choose scientific journalism to better explain darwinism to the french poeple. this meeting will be follow by a dedication of hos book in the library.

I am now engaged on investigations to better understand the relationships between Charles Darwin and entomology, and specially the French entomologists.