Dataset Information

Evolution of IESs and scrambling in the actin I gene in hypotrichous ciliates.

ABSTRACT: Germ-line (micronuclear) genes in hypotrichous ciliates are interrupted by numerous, short, noncoding, AT-rich segments called internal eliminated segments, or IESs. IESs divide a gene into macronuclear destined segments, or MDSs. IESs are excised from micronuclear genes, and the MDSs are spliced when a micronuclear genome is processed into a macronuclear genome after cell mating. In the micronuclear version of the actin I gene intramolecular recombination between IESs during evolution has put MDSs into a scrambled disorder in some but not all hypotrichs. Studies using rDNA sequences to define phylogenetic relationships among eight hypotrichs suggests that evolution of the micronuclear actin I gene proceeds by successive addition of IESs in earlier diverging species, without MDS scrambling. Continued addition of IESs and recombination among IESs in later diverging species produced actin I genes with scrambled MDSs. Subsequent to MDS scrambling, additional IESs were inserted into the more recently evolved species. Thus, IES insertions and gene scrambling occur in a progressive manner during species evolution to produce micronuclear actin I genes of increasing structural complexity.

SUBMITTER: Hogan DJ

PROVIDER: S-EPMC64990 | biostudies-literature | 2001 Dec

REPOSITORIES: biostudies-literature

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Evolution of IESs and scrambling in the actin I gene in hypotrichous ciliates.

Hogan D J DJ Hewitt E A EA Orr K E KE Prescott D M DM Müller K M KM

Proceedings of the National Academy of Sciences of the United States of America 20011211 26

Germ-line (micronuclear) genes in hypotrichous ciliates are interrupted by numerous, short, noncoding, AT-rich segments called internal eliminated segments, or IESs. IESs divide a gene into macronuclear destined segments, or MDSs. IESs are excised from micronuclear genes, and the MDSs are spliced when a micronuclear genome is processed into a macronuclear genome after cell mating. In the micronuclear version of the actin I gene intramolecular recombination between IESs during evolution has put M ...[more]

PMID: 11742064

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Dataset Information

Evolution of IESs and scrambling in the actin I gene in hypotrichous ciliates.

Publications

Evolution of IESs and scrambling in the actin I gene in hypotrichous ciliates.

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