CROSSING THE SPECIES BARRIER. “The origin of bacterial genes in eukaryotes. In addition to gene duplication, HGT events have played a major role in the emergence of the eukaryotic cell, as is evident by the significant amount of genes that clearly are of bacterial origin that reside on eukaryotic genomes.” (HGT = Horizontal Gene Transfer).
http://www.biochemsoctrans.org/content/41/1/451.full