GENETIC SYSTEMS AND SOCIAL EVOLUTION
Sexual reproduction is a ubiquitous trait of eukaryotes. Yet, alternative reproductive systems, such as female clonality, male clonality, and hemi-clonal reproduction, have repeatedly evolved in diverse taxa. Our research aims to understand the proximate and ultimate mechanisms underlying transitions between genetic systems in the highly diverse and ecologically successful ant family.
Ant societies are characterized by a reproductive division of labor between queen and worker females and a haplo-diploid sex-determination system. In most species, females are produced by sexual reproduction and develop into queens or workers depending on environmental factors, while males develop from unfertilized, haploid eggs. Deviations from this canonical reproduction schema have however been documented in several ant genera. In some taxa, the genetic makeup of an egg determines its developmental fate: workers arise from hybridization between divergent sympatric lineages, whereas queens are always purebred individuals (social hybridogenesis). In some of these species, queens are clones of their mother, while males are clones of their father (double-clonality). We also recently discovered an extraordinary reproductive system in the yellow crazy ant, resulting in males carrying maternal and paternal genomes in different cells of their body (chimerism). We employ population genetic, genomic, and cytological approaches to understand how division of labor and haplo-diploidy fostered the repeated evolution of such unusual genetic systems.
Our group currently works on the longhorn crazy ant (Paratrechina longicornis), the yellow crazy ant (Anoplolepis gracilipes), the argentine ant (Linepithema humile), and desert ants of the genus Cataglyphis.