ISSN:
1572-9931
Source:
Springer Online Journal Archives 1860-2000
Topics:
Biology
,
Medicine
Notes:
Abstract We describe a novel approach for the isolation of null mutations in a vital Chinese hamster ovary (CHO) cell housekeeping gene. Our experimental strategy required introduction of an expressible DNA clone encoding a recessive emetine-resistance allele of ribosomal protein S14 into wild-type CHO cells. Transgene heterozygote (TGH) cell lines, which harbor multiple emetine-resistance S14 transgenes, survive mutations that inactivate the CHO RPS14 locus by virtue of the transgenes' biological function. Null mutations inRPS14 yield TGH clones that display the transgene's drug-resistance phenotype. A large collection of emetine-resistant clones was isolated from one TGH cell line and shown to consist of three types of S14 mutations: (1) nonsense null mutations in theRPS14 protein coding sequence; (2) missense null mutations that affect S14 amino acid residues that have been conserved stringently during eukaryotic evolution, and (3) a recurrent missense mutation that results in a new, functionalRPS14 emetine-resistance allele.
Type of Medium:
Electronic Resource
URL:
http://dx.doi.org/10.1007/BF01233092
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