Data from: The genomes of polyextremophilic Cyanidiales contain 1% horizontally transferred genes with diverse adaptive functions

The role and extent of horizontal gene transfer (HGT) in eukaryotes are
hotly disputed topics that impact our understanding of the origin of
metabolic processes and the role of organelles in cellular evolution. We
addressed this issue by analyzing 10 novel Cyanidiales genomes and
determined that 1% of their gene inventory is HGT-derived. Numerous HGT
candidates share a close phylogenetic relationship with prokaryotes that
live in similar habitats as the Cyanidiales and encode functions related
to polyextremophily. HGT candidates differ from native genes in
GC-content, number of splice sites, and gene expression. HGT candidates
are more prone to loss, which may explain the absence of a eukaryotic
pan-genome. Therefore, the lack of a pan-genome and cumulative effects
fail to provide substantive arguments against our hypothesis of recurring
HGT followed by differential loss in eukaryotes. The maintenance of 1%
HGTs, even under selection for genome reduction, underlines the importance
of non-endosymbiosis related foreign gene acquisition.