Linked Life Data

6305508

Source:http://linkedlifedata.com/resource/pubmed/id/6305508

Statements in which the resource exists as a subject.
PredicateObject
rdf:type
lifeskim:mentions
pubmed:issue
2
pubmed:dateCreated
1983-8-26
pubmed:abstractText
Gamma rays have been used to induce Chinese hamster ovary cell mutants in which the entire locus for dihydrofolate reductase (DHFR) has been eliminated. These mutants were isolated in two steps from a methotrexate-resistant clone (Flintoff, Davidson, and Siminovitch (1976). Somat. Cell Genet. 2, 245-262). The resistant cells contain amplified copies of a mutant dhfr gene that codes for a drug-resistant form of the enzyme. In the first step, methotrexate-sensitive mutants of the amplified line were selected. These mutants exhibit a reduced level of DHFR activity and contain a reduced number of dhfr genes. The remaining DHFR activity is methotrexate-sensitive. These mutants appear to be hemizygotes that have lost all copies of the amplified altered dhfr genes and retain one wild-type allele. In a second mutagenic step, mutants completely deficient in DHFR activity were isolated. Three of four of these mutants were the result of double deletions: they lack all traces of dhfr DNA sequences. The fourth mutant contains a deletion that extends through the 5' half of the dhfr gene. The hemizygotes for dhfr should be useful for the study of mutation at an autosomal mammalian locus without the complications of diploidy.
pubmed:grant
pubmed:language
eng
pubmed:journal
pubmed:citationSubset
IM
pubmed:chemical
pubmed:status
MEDLINE
pubmed:month
Jun
pubmed:issn
0092-8674
pubmed:author
pubmed:issnType
Print
pubmed:volume
33
pubmed:owner
NLM
pubmed:authorsComplete
Y
pubmed:pagination
405-12
pubmed:dateRevised
2007-11-14
pubmed:meshHeading
pubmed:year
1983
pubmed:articleTitle
Deletion of the diploid dihydrofolate reductase locus from cultured mammalian cells.
pubmed:publicationType
Journal Article, Research Support, U.S. Gov't, P.H.S., Research Support, Non-U.S. Gov't