Phylogenetic evidence for the acquisition of ribosomal RNA introns subsequent to the divergence of some of the major Tetrahymena groups

TY - JOUR

T1 - Phylogenetic evidence for the acquisition of ribosomal RNA introns subsequent to the divergence of some of the major Tetrahymena groups

AU - Sogin, M L

AU - Ingold, A

AU - Karlok, M

AU - Nielsen, Henrik

AU - Engberg, J

N1 - Keywords: Animals; Base Sequence; Evolution; Introns; Macromolecular Substances; Phylogeny; RNA, Ribosomal; Species Specificity; Tetrahymena

PY - 1986

Y1 - 1986

N2 - Previous work has demonstrated the presence of a self-splicing intron in the large subunit ribosomal RNA coding region in some strains of the ciliate protozoan Tetrahymena. Sequence comparisons of the intron regions from six Tetrahymena species showed these to fall into three homology groups. In an attempt to evaluate the evolutionary origins of the intervening sequences, we have now determined complete small subunit ribosomal RNA gene sequences from 13 species of Tetrahymena and the absolute number of nucleotide differences between the sequences was used to construct a phylogenetic tree. This phylogeny was consistent with the groupings suggested by comparisons of other biochemical characters including cytoskeletal proteins, isozyme analyses, and restriction maps of complete rRNA transcription units. The homology groupings that were based upon the intron sequence data do not agree with the relationships inferred from the small subunit rRNA sequence data. These observations are taken to indicate that the intron character has been acquired independently in different species at a stage later than the branching out of the species.

AB - Previous work has demonstrated the presence of a self-splicing intron in the large subunit ribosomal RNA coding region in some strains of the ciliate protozoan Tetrahymena. Sequence comparisons of the intron regions from six Tetrahymena species showed these to fall into three homology groups. In an attempt to evaluate the evolutionary origins of the intervening sequences, we have now determined complete small subunit ribosomal RNA gene sequences from 13 species of Tetrahymena and the absolute number of nucleotide differences between the sequences was used to construct a phylogenetic tree. This phylogeny was consistent with the groupings suggested by comparisons of other biochemical characters including cytoskeletal proteins, isozyme analyses, and restriction maps of complete rRNA transcription units. The homology groupings that were based upon the intron sequence data do not agree with the relationships inferred from the small subunit rRNA sequence data. These observations are taken to indicate that the intron character has been acquired independently in different species at a stage later than the branching out of the species.

M3 - Journal article

C2 - 3830129

SN - 0261-4189

VL - 5

SP - 3625

EP - 3630

JO - E M B O Journal

JF - E M B O Journal

IS - 13

ER -