Description du projet
Aperçu des mécanismes évolutifs du comportement social
La théorie prédit que les comportements altruistes ne devraient se produire qu’entre individus apparentés. De manière surprenante, l’effet dit «Barbe verte» conduit des individus génétiquement non apparentés à coopérer pour autant qu’ils partagent le même locus de coopération. L’objectif principal du projet GreenAnt, financé par l’UE, est d’étudier un élément génétique de l’effet Barbe Verte: le supergène Social b, chez la fourmi de feu, où les porteurs tuent les reines non porteuses. Les chercheurs souhaitent comprendre les fondements génétiques de l’effet Barbe Verte chez cette espèce, ainsi que son maintien et sa propagation. Les résultats fourniront des informations fondamentales sur les mécanismes évolutifs du comportement social.
Objectif
Greenbeard genes are selfish genetic elements (SGEs) that favor their own transmission by increasing the fitness of other carrying individuals. Such a phenotype, can only occur if a gene or a group of tightly linked genes produce (1) a conspicuous phenotype, (2) the ability to recognize this phenotype, allowing the bearer individual to discriminate carriers from non-carriers and (3) a nepotistic behavior in favor of carriers. These extraordinary SGEs can have profound evolutionary consequences on genomes and social behavior. The first identified Greenbeard haplotype was in the fire ant Solenopsis invicta. In this species, the Social b (Sb) supergene, an 11 Mb non-recombining region is associated with a Greenbeard effect. Discriminating on cuticular chemical profiles, carrier ant workers spread the Sb supergene by killing non-bearer queens. In this project I aim to identify the genetic basis of the queen-discrimination ability of Greenbeard-carrier ant workers. I will first compare the molecular evolution of the Sb supergene with the non-driving homologous haplotype over multiple bearer and outgroup species. Then I will compare patterns of expression of Sb supergene genes in antennae and brains between workers. Lastly, I will functionally validate candidate genes by genetically altering their sequence in workers. I will assay the impact of the knock out on the Greenbeard effect by testing the queen-discrimination ability of transformed workers. Using this combination of techniques and analyses, the GreenAnt project will tackle the molecular basis and evolution of Greenbeard genes in metazoan organisms.
Champ scientifique
Programme(s)
Régime de financement
MSCA-IF-EF-ST - Standard EFCoordinateur
1015 LAUSANNE
Suisse