dCTP misincorporation in a Chinese hamster mutator phenotype: the role of GGA genetic context.
Clone CSA7 is a CHEF18 hamster cell line that shows an increased intracellular accumulation of dCTP. To localize the mutations that accumulate spontaneously in a functional gene of such a mutator phenotype, independent CSA7 mutants of the hypoxanthine-guanine phosphoribosyl transferase (hprt) gene were isolated and screened by a polymerase chain reaction-single strand conformation polymorphism technique. Sixty-two percent of mutants produced detectable changes of the strand migration profile and the mutations were preferentially localized in the exons 3 (31%) and 6 (62%). The sequencing of such exons revealed that the rate of C base incorporation was the major mutation pathway and that the A base of a GGA sequence was the preferential site of misincorporation.
Rainaldi
G
G
Genetica e Biochimica Tossicologica, Istituto di Mutagenesi e Differenziamento, CNR, Via Svezia 10, Pisa, Italy.
Meneveri
R
R
Mariani
L
L
Ginelli
E
E
Moretti
A
A
Vatteroni
L
L
D000818:Animals; D001483:Base Sequence; D002460:Cell Line; D006224:Cricetinae; D003412:Cricetulus; D004247:DNA / Q000235:genetics / Q000378:metabolism; D003845:Deoxycytosine Nucleotides / Q000378:metabolism*; D005091:Exons; D007041:Hypoxanthine Phosphoribosyltransferase / Q000235:genetics; D008969:Molecular Sequence Data; D009154:Mutation; D010641:Phenotype; D016133:Polymerase Chain Reaction; D018807:Polymorphism, Single-Stranded Conformational
D003845:Deoxycytosine Nucleotides; C024107:2'-deoxycytidine 5'-triphosphate; D004247:DNA; D007041:Hypoxanthine Phosphoribosyltransferase