Know more

Michèle Tixier-Boichard, Senior Research Scientist, began her research on quantitative genetics in the laying hen at Jouy-en-Josas, then on the molecular genetics of feather color before enlargening here studies to the characterization to animal genetic resources. After having launched the CRB-Anim infrastructure on animal genetic resources, she is currently coordinator of the RARe Infrastructure and leader of the core faciltiies team at the Animal Genetics and Integrative Biology Unit (INRAE Île-de-France-Jouy-en-Josas-Antony). She works on both national and international levels to collect, characterize, conserve and distribute biological resources useful for agricultural research and knowledge of biodiversity.

Genetic resources are a part of our heritage that are essential for advancing research and enabling us to meet the major challenges of tomorrow. Food, both in quantity and quality, energy, transport, climate change, health, biomaterials, ... The stakes are high. "In the future, we may need certain breeds of animals, strains of micro-organisms or varieties of plants, which is why genetic resources are essential. These allow, among other things to support the breeding and agriculture of today and tomorrow, but also to participate in the maintenance of biodiversity." The RARe (Agricultural Resources for Research) infrastructure is a national, distributed, multi-organism infrastructure that aims to preserve and characterize biological and genetic resources of animal, plant, microbial species, and the environment, to contribute to the evolution  of agricultural systems in response to global changes.

The Silver-Dufrenoy medal was awarded to Ronan Griot, for his PhD studies on "The development of tools and methods for genomic selection in European sea bass and gilthead seabream", defended on March 30th, 2021 at the University Paris-Saclay with a jury presided by Pr Etienne Verrier.

Ronan Griot's PhD abstract:
As any animal production, aquaculture must face many disease outbreaks leading to high mortality that can be controlled by selective breeding. With easy access to whole genome sequencing technologies and genomic tools, the use of genomic data in selective breeding has to be considered. The purpose of this thesis was to develop tools and methods to implement genomic selection to improve resistance to viral nervous necrosis and vibriosis in seabass and to pasteurellosis in seabream.

First, we developed a simple and efficient parentage assignment tool based on a method using Mendelian transmission probabilities, estimated from the population of offspring to assign. Then, we studied the genetic architecture of the traits by variance component estimation and QTL detection. We showed that the viral nervous necrosis resistance in seabass is an oligogenic trait with a moderate heritability and controlled by a strong QTL effect. We also showed that resistance to vibriosis in seabass and to pasteurellosis in seabream are two polygenic traits with moderate. Finally, we evaluated the accuracy of genomic selection with different marker densities and different training population sizes, using or not the information on the viral nervous necrosis resistance QTL in seabass. We showed that genomic selection increased selection accuracy by 8.9% to 24.5% in the species and traits we studied. Then, we showed that accounting for the viral nervous necrosis resistance QTL information in seabass increased selection accuracy by 10.5% to 26.3%.

This thesis evaluated the efficiency of the genomic selection in seabass and seabream, and develop tools making the use of genomic data in breeding schemes easier. Thus, we now have a framework to implement and optimize the genomic selection in seabass and seabream.