Linked Life Data

2591963

Source:http://linkedlifedata.com/resource/pubmed/id/2591963

Statements in which the resource exists as a subject.
PredicateObject
rdf:type
lifeskim:mentions
pubmed:issue
4
pubmed:dateCreated
1990-1-25
pubmed:abstractText
Human ribosomal DNA has been inferred to be organized in tandem repeat units of 44 kb, of which only 13 kb is transcribed into preribosomal RNA. Unfortunately, it has remained difficult to examine the intact repeat structure directly, because even a single repeat unit is too large to be accommodated in conventional cloning systems. Here we report the isolation of intact repeat units using yeast artificial chromosomes as a cloning tool. With a spacer sequence specific to human ribosomal DNA used as a probe, 27 clones were identified among 17,000 YACs (about 0.7 genomic equivalent of total human DNA). Fourteen clones contained only a small portion of rDNA; the other 13 contained most or all of the rDNA repeat unit, and 8 of those were studied in further detail. They contained 1 to 1.5 repeat units of rDNA with all of the expected EcoRI and HindIII fragments. These clones provide possible starting material for the analysis of expression of a single unit of rDNA. Unexpectedly, however, only the four smaller clones (70 to 90 kb) were completely composed of standard rDNA sequences; four larger clones (up to 950 kb in length) contained additional "non-rDNA" sequences, at either one or both ends of the repeat unit. Analysis of these atypical rDNA clones suggests that their inserts either are scattered in the genome or are localized in a nucleolar organizer region that is more complex than previously recognized.
pubmed:language
eng
pubmed:journal
pubmed:citationSubset
IM
pubmed:chemical
pubmed:status
MEDLINE
pubmed:month
Nov
pubmed:issn
0888-7543
pubmed:author
pubmed:issnType
Print
pubmed:volume
5
pubmed:owner
NLM
pubmed:authorsComplete
Y
pubmed:pagination
752-60
pubmed:dateRevised
2006-11-15
pubmed:meshHeading
pubmed:year
1989
pubmed:articleTitle
Complete human rDNA repeat units isolated in yeast artificial chromosomes.
pubmed:affiliation
Department of Molecular Microbiology, Washington University School of Medicine, St. Louis, Missouri 63110.
pubmed:publicationType
Journal Article, Research Support, U.S. Gov't, P.H.S.