Statements in which the resource exists as a subject.
PredicateObject
rdf:type
lifeskim:mentions
pubmed:issue
22
pubmed:dateCreated
2002-5-28
pubmed:abstractText
The hexamer repeat sequence (TTAGGG)(n), found at the ends of all vertebrate chromosomes, was previously identified as the main building element of one member of a HindIII satellite DNA family characterized in the genome of the bivalve mollusc Donax trunculus. It was also found in 22 perfect tandem repeats in a cloned junction region juxtaposed to the proper satellite sequence, from which the DNA tract encompassing the clustered tandem copies was excised and subcloned. Here, the chromosomal distribution of (TTAGGG)(n) sequences in the Donax was studied by the sensitivity to Bal31 exonuclease digestion, fluorescence in situ hybridization (FISH) on metaphase chromosomes and rotating-field gel electrophoresis. To verify the occurrence of the hexamer repeat in the genomes of taxonomically related molluscs and other marine invertebrates, genomic DNA from the mussel Mytilus galloprovincialis and the echinoderm Holothuria tubulosa was also analyzed. The kinetics of Bal31 hydrolysis of high molecular mass DNA from the three marine invertebrates revealed a marked decrease over time of the hybridization with the cloned (TTAGGG)(22) sequence, concomitantly with a progressive shortening of the positively reacting DNA fragments. This revealed a marked susceptibility to exonuclease consistent with terminal positioning on the respective chromosomal DNAs. In full agreement, FISH results with the (TTAGGG)(22) probe showed that the repeat appears located in telomeric regions in all chromosomes of both bivalve molluscs. The presence of (TTAGGG)(n) repeat tracts in marine invertebrate telomeres points to its wider distribution among eukaryotic organisms and suggests an ancestry older than originally presumed from its vertebrate distinctiveness.
pubmed:language
eng
pubmed:journal
pubmed:citationSubset
IM
pubmed:chemical
pubmed:status
MEDLINE
pubmed:month
May
pubmed:issn
0021-9258
pubmed:author
pubmed:issnType
Print
pubmed:day
31
pubmed:volume
277
pubmed:owner
NLM
pubmed:authorsComplete
Y
pubmed:pagination
19839-46
pubmed:dateRevised
2006-11-15
pubmed:meshHeading
pubmed-meshheading:11907038-Animals, pubmed-meshheading:11907038-Base Sequence, pubmed-meshheading:11907038-Blotting, Southern, pubmed-meshheading:11907038-Chromosomes, pubmed-meshheading:11907038-Cloning, Molecular, pubmed-meshheading:11907038-DNA, pubmed-meshheading:11907038-Dose-Response Relationship, Drug, pubmed-meshheading:11907038-Endodeoxyribonucleases, pubmed-meshheading:11907038-Genome, pubmed-meshheading:11907038-In Situ Hybridization, Fluorescence, pubmed-meshheading:11907038-Kinetics, pubmed-meshheading:11907038-Microscopy, Fluorescence, pubmed-meshheading:11907038-Models, Genetic, pubmed-meshheading:11907038-Molecular Sequence Data, pubmed-meshheading:11907038-Mollusca, pubmed-meshheading:11907038-Sea Cucumbers, pubmed-meshheading:11907038-Telomere, pubmed-meshheading:11907038-Time Factors
pubmed:year
2002
pubmed:articleTitle
Telomeric localization of the vertebrate-type hexamer repeat, (TTAGGG)n, in the wedgeshell clam Donax trunculus and other marine invertebrate genomes.
pubmed:affiliation
Department of Molecular and Cell Biology, Institut de Biologia Molecular de Barcelona, CSIC, E-08034 Barcelona, Spain.
pubmed:publicationType
Journal Article, Research Support, Non-U.S. Gov't