Summary

The advent of comparative genomics has revolutionized the study of the origin and evolution of eukaryotes and their organelles. Genomic analysis has revealed that the endosymbiosis that gave rise to plastids – the light-harvesting apparatus of photosynthetic eukaryotes – had a profound impact on the genetic composition of the host, far beyond the contribution of cyanobacterial genes for plastid-specific functions. Here I discuss recent advances in our appreciation of the mosaic nature of the eukaryotic nuclear genome, and the ongoing role endosymbiosis plays in shaping its content