Lineage-specific fragmentation and nuclear relocation of the mitochondrial cox2 gene in chlorophycean green algae (Chlorophyta)

► We report the distribution and localization of intact and split cox2 genes in the Chlorophyta. ► All Chlorophycean algae exhibited split cox2 genes. ► Cox2 split gene distribution divides Chlorophyceae into two distinct groups: Scenedesmus-like and Chlamydomonas-like. ► We present a scenario describing how cox2 gene splitting and migration to the nucleus took place. ► Cox2 gene organization and localization gives important insights into algal phylogenetic relationships.