BIOMAT Database Logo BIOMAT Database Logo

High-frequency deletion event at aprt locus of CHO cells: detection and characterization of endpoints. 1989

P Dewyse, and W E Bradley
Institut du Cancer de Montréal, Québec, Canada.

Two mechanisms are implicated in generating recessive drug resistance mutants at the adenine phosphoribosyltransferase (aprt) locus of Chinese hamster ovary (CHO) cells, one of which is a spontaneous high-frequency deletion of the entire gene. We have isolated and mapped a 19-kb fragment carrying aprt and its flanking sequences. A Southern blot study of 198 independent deletion mutants revealed that two different mutants have one of their breakpoints within the 19-kb region analyzed. One of these has an upstream breakpoint which could be narrowed down to a 4-kb fragment containing repetitive sequences. The other mutant has a breakpoint within a 410-bp sequence located 8.5 kb downstream of the aprt gene and which carries several elements similar to those signaling V-(D)-J joining in immunoglobulin and T-cell receptor gene rearrangements. In each case the other breakpoint lay outside of the analyzed region. These results support the previous indications that the deletions created by this spontaneous event are large.

UI MeSH Term Description Entries
D008969 Molecular Sequence Data Descriptions of specific amino acid, carbohydrate, or nucleotide sequences which have appeared in the published literature and/or are deposited in and maintained by databanks such as GENBANK, European Molecular Biology Laboratory (EMBL), National Biomedical Research Foundation (NBRF), or other sequence repositories. Sequence Data, Molecular,Molecular Sequencing Data,Data, Molecular Sequence,Data, Molecular Sequencing,Sequencing Data, Molecular
D009154 Mutation Any detectable and heritable change in the genetic material that causes a change in the GENOTYPE and which is transmitted to daughter cells and to succeeding generations. Mutations
D010430 Pentosyltransferases Enzymes of the transferase class that catalyze the transfer of a pentose group from one compound to another.
D002460 Cell Line Established cell cultures that have the potential to propagate indefinitely. Cell Lines,Line, Cell,Lines, Cell
D003001 Cloning, Molecular The insertion of recombinant DNA molecules from prokaryotic and/or eukaryotic sources into a replicating vehicle, such as a plasmid or virus vector, and the introduction of the resultant hybrid molecules into recipient cells without altering the viability of those cells. Molecular Cloning
D004247 DNA A deoxyribonucleotide polymer that is the primary genetic material of all cells. Eukaryotic and prokaryotic organisms normally contain DNA in a double-stranded state, yet several important biological processes transiently involve single-stranded regions. DNA, which consists of a polysugar-phosphate backbone possessing projections of purines (adenine and guanine) and pyrimidines (thymine and cytosine), forms a double helix that is held together by hydrogen bonds between these purines and pyrimidines (adenine to thymine and guanine to cytosine). DNA, Double-Stranded,Deoxyribonucleic Acid,ds-DNA,DNA, Double Stranded,Double-Stranded DNA,ds DNA
D004252 DNA Mutational Analysis Biochemical identification of mutational changes in a nucleotide sequence. Mutational Analysis, DNA,Analysis, DNA Mutational,Analyses, DNA Mutational,DNA Mutational Analyses,Mutational Analyses, DNA
D005796 Genes A category of nucleic acid sequences that function as units of heredity and which code for the basic instructions for the development, reproduction, and maintenance of organisms. Cistron,Gene,Genetic Materials,Cistrons,Genetic Material,Material, Genetic,Materials, Genetic
D000228 Adenine Phosphoribosyltransferase An enzyme catalyzing the formation of AMP from adenine and phosphoribosylpyrophosphate. It can act as a salvage enzyme for recycling of adenine into nucleic acids. EC 2.4.2.7. AMP Pyrophosphorylase,Transphosphoribosidase,APRTase,Phosphoribosyltransferase, Adenine,Pyrophosphorylase, AMP
D000818 Animals Unicellular or multicellular, heterotrophic organisms, that have sensation and the power of voluntary movement. Under the older five kingdom paradigm, Animalia was one of the kingdoms. Under the modern three domain model, Animalia represents one of the many groups in the domain EUKARYOTA. Animal,Metazoa,Animalia

Related Publications

P Dewyse, and W E Bradley
High-frequency nonrandom mutational event at the adenine phosphoribosyltransferase (aprt) locus of sib-selected CHO variants heterozygous for aprt.
January 1982, Somatic cell genetics,
P Dewyse, and W E Bradley
Spontaneous CHO APRT heterozygotes reflect high-frequency, allele-specific deletion of the chromosome Z4 APRT gene.
November 1989, Somatic cell and molecular genetics,
P Dewyse, and W E Bradley
Targeted gene replacement at the endogenous APRT locus in CHO cells.
September 1990, Somatic cell and molecular genetics,
P Dewyse, and W E Bradley
Effect of vector topology on homologous recombination at the CHO aprt locus.
May 1993, Somatic cell and molecular genetics,
P Dewyse, and W E Bradley
Evidence for high-frequency allele loss at the aprt locus in TK6 human lymphoblasts.
October 1993, Mutation research,
P Dewyse, and W E Bradley
Spontaneous deletion formation at the aprt locus of hamster cells: the presence of short sequence homologies and dyad symmetries at deletion termini.
June 1986, The EMBO journal,
P Dewyse, and W E Bradley
Targeted base substitutions and small deletions induced by neocarzinostatin at the APRT locus in plateau-phase CHO cells.
January 1997, Mutation research,
P Dewyse, and W E Bradley
Loss of heterozygosity in mammalian cell mutagenesis: molecular analysis of spontaneous mutations at the aprt locus in CHO cells.
September 1990, Carcinogenesis,
P Dewyse, and W E Bradley
Long CTG tracts from the myotonic dystrophy gene induce deletions and rearrangements during recombination at the APRT locus in CHO cells.
May 2003, Molecular and cellular biology,
P Dewyse, and W E Bradley
DNA sequence analysis of mutations induced by melphalan in the CHO aprt locus.
November 1992, Cancer genetics and cytogenetics,
Copied contents to your clipboard!