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The Chloroplast Genome of Euglena mutabilis —Cluster Arrangement, Intron Analysis, and Intrageneric Trends
Author(s) -
Dabbagh Nadja,
Preisfeld Angelika
Publication year - 2016
Publication title -
journal of eukaryotic microbiology
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.067
H-Index - 77
eISSN - 1550-7408
pISSN - 1066-5234
DOI - 10.1111/jeu.12334
Subject(s) - biology , euglena , intron , euglena gracilis , genome , evolutionary biology , group i catalytic intron , phylogenetic tree , flagellate , botany , chloroplast , genetics , gene , rna splicing , rna
A comparative analysis of the chloroplast genome of Euglena mutabilis underlined a high diversity in the evolution of plastids in euglenids. Gene clusters in more derived Euglenales increased in complexity with only a few, but remarkable changes in the genus Euglena . Euglena mutabilis differed from other Euglena species in a mirror‐inverted arrangement of 12 from 15 identified clusters, making it very likely that the emergence at the base of the genus Euglena , which has been considered a long branch artifact, is truly a probable position. This was corroborated by many similarities in gene arrangement and orientation with Strombomonas and Monomorphina , rendering the genome organization of E. mutabilis in certain clusters as plesiomorphic feature. By RNA analysis exact exon–intron boundaries and the type of the 77 introns identified were mostly determined unambiguously. A detailed intron study of psb C pointed at two important issues: First, the number of introns varied even between species, and no trend from few to many introns could be observed. Second, mat 1 was localized in Eutreptiales exclusively in intron 1, and mat 2 was not identified. With the emergence of Euglenaceae in most species, a new intron containing mat 2 inserted in front of the previous intron 1 and thereby became intron 2 with mat 1.