| Abstrakt: |
Abstract:Euglena proximais a common, globally dispersed, and easily identified photosynthetic euglenoid. Previous phylogenetic analyses using nuclear-encoded small subunit (SSU) and large subunit (LSU) rRNA genes revealed that this taxon was paraphyletic with other Euglenaspecies and was positioned as sister to all Euglenaceae. Despite this, authors were reluctant to remove this taxon from Euglenauntil additional data, or taxa pairing with E. proxima,were obtained because it created a monotypic genus. To clarify the taxonomy, the chloroplast genome of E. proximawas sequenced and compared with those of other photosynthetic euglenoids. Phylogenomic analyses were performed comparing 79 chloroplast-encoded genes from E. proximawith those found in seven photosynthetic euglenoids and three prasinophytes, the group from which the euglenoid chloroplast was probably derived. These analyses resulted in highly supported phylogenomic trees with topologies that were consistent with all previous phylogenetic analyses, i.e. they positioned E. proximaas sister to all of the Euglenaceae. In addition, a syntenic comparison was conducted between E. proximaand the chloroplast genomes of two Euglenataxa in order to determine their similarities. This analysis showed that the construction of the E. proximachloroplast genome was very different from that of the two Euglenachloroplast genomes, which were extremely similar to each other. Based on these data, E. proximawas removed from Euglena, and a new genus, Euglenaformis, was erected to clarify the true relationship of this taxon to the rest of the photosynthetic euglenoids. |
