6533b837fe1ef96bd12a348c

RESEARCH PRODUCT

Subrepeats result from regional DNA sequence conservation in tandem repeats in Chironomus telomeres

Erwin R. SchmidtJan-erik EdströmLena Nielsen

subject

GeneticsGenomic LibraryUnequal crossing overBase SequencebiologyMolecular Sequence DataGene AmplificationDNAbiology.organism_classificationBiological EvolutionGenomeLinker DNAChironomidaeDNA sequencingSpecies SpecificityTandem repeatStructural BiologyMolecular evolutionSequence Homology Nucleic AcidAnimalsChironomusMolecular BiologyRepetitive Sequences Nucleic AcidRepeat unit

description

Repeat units, widespread in eukaryotic genomes, are often partially or entirely built up of subrepeats. Homogenization between whole repeat units arranged in tandem usually can best be understood as a result of unequal crossing over. Such a mechanism is less plausible for maintaining similarities between subrepeats within a repeat unit when present in a regular array. In Chironomus telomeres, large blocks of tandemly repeated approximately 350 base-pair units contain two or three pairs of subrepeats with high mutual identities, embedded in linker DNA, non-repetitive within the repeat unit. Measurements of evolutionary base changes in two closely related species, Chironomus tentans and Chironomus pallidivittatus, permit us to conclude that the subrepeat arrangement is best explained as a consequence of regional sequence conservation after an earlier duplication of an ancestral half-unit.

yearjournalcountryeditionlanguage
1990-12-01Journal of Molecular Biology
https://doi.org/10.1016/0022-2836(90)90385-y