1 - Maternal effect via the egg
Maternal effects occur when a mother's phenotype or her environment influence her offspring's phenotype. They represent an important processes (beside genetics) by which the phenotype is shaped. Maternal effects can act at three different stages
- prezygotic stage
- postzygotic-prenatal stage
- postzygotic-postnatal stage
In particular, maternal effects encountered during the development of the embryo could have a great importance in shaping life-history evolution. In birds, as in oviparous species, the egg (prezygotic-prenatal stage) constitutes the unique environment where the embryo develops and therefore represents an important source by which mother can modulate the phenotype of her offspring. A major aim of my studies is to investigate the importance of the different egg components (shell, white and yolk) in shaping individual phenotype in birds.
2 - Role of maternal effect in host-parasite interactions
Despite the ecological importance of maternal effects in host-parasite interactions, their role has been relatively neglected to date. In collaboration with Dr. Thierry Boulinier, Dr Karen McCoy, Vincent Staszewski and Dr. Torkild Tveraa, we are examining how mothers influence the immune defence of their young in an environment that varies in space and time. Using kittiwakes (Rissa tridactyla) as a model organism, we are looking for mechanisms and ecological consequences of maternal transfer of passive immunity against the tick Ixodes uriae and associated microparasites such as Borrelia burgdorferi.
The immune system is a major component of parasite resistance in vertebrates. The study of immunology in an ecological context, referred to as 'immuno-ecology', has proved fruitful to understand host-parasite interaction. To investigate which factors determine the ecological causes and consequences of immune responses in the face of a pathogen, I am studying aspects of immunity in growing individuals. For this purpose, I am using the kittiwake (in collaboration with Dr. Thierry Boulinier, Dr. Verena Gill and Dr. Scott Hatch) and tawny owls (in collaboration with Prof. Alexandre Roulin and Dr. Pierre Bize) as model organisms. I am particularly interested in the long-term consequences of mounting an immune response as a nestling.
Adaptive function of colour polymorphisms
The display of alternative heritable colour morphs within a population is frequently found in animals and plants. Even though colour polymorphism is often not neutral with respect to fitness components, their function and maintenance remains a largely unsolved problem. Using the tawny owl as a model organism, and in collaboration with Dr. Pierre Bize, Romain Piault, Dr. Anne-Lyse Roulin and Prof. Alexandre Roulin, we are examining why different morphs differ in many respects including physiology and behaviour. This is an important aspect to understand how genetic colour polymorphisms are maintained in natural population.