Centrophilic Retrotransposons in Eukaryotic Genomes

Centromeres are critical for cell division, loading CENH3/CENPA histone variant nucleosomes, directing kinetochore formation, and allowing chromosome segregation. Despite their conserved function, centromere size and structure are diverse across species, termed the ‘centromere paradox’. However, the mechanisms of centromeric sequence change, and the evolutionary drivers are unclear. We have assembled the Arabidopsis thaliana pancentromere, which has revealed extreme intraspecies diversity, where the satellite repeats have undergone extensive recombination and concerted evolution. Additionally, the satellite repeat arrays have been invaded by centrophilic ATHILA retrotransposons. In this talk I will examine the structure and evolution of ATHILA retrotransposons, and compare this to other centrophilic repeat elements we have identified across eukaryotes. I will discuss models for centromere evolution, including the roles of female meiotic drive, and the possible roles of centrophilic transposons in these dynamics.