title: Restoration of Mitochondrial Gene Expression Using a Cloned Human Gene in Chinese Hamster Lung Cell Mutant.
abstract: BACKGROUND
  Gal-32 is a Chinese hamster lung cell nuclear mutant that is unable to grow in galactose due to a defect in mitochondrial protein synthesis. Since the product of the Gal-32 gene was unknown, it was imperative to use phenotypic complementation to clone a human gene that corrected the Gal-32 mutation.
  
  
  RESULTS
  Recessive Gal-32 cells were co-transformed with pSV2-neoplasmid DNA and recombinant DNA from a human genomic library containing the dominant human Gal+gene and a chloramphenicol-resistance (camr) gene present in the pSV13 vector. Primary transformants were selected by growth in galactose and the neomycin analog G418. In order to rescue the human Gal+gene, a genomic library was constructed with primary transformant DNA and the pCV108 cosmid vector. Thecamrgene was used to identify clones with the nearby human sequences. DNA from twocamr,Alu-hybridizing clones was able to transform the recessive Gal-32 cells to the Gal+phenotype and to restore mitochondrial protein synthesis.
  
  
  CONCLUSIONS
  These data demonstrate the isolation of two pCV108-transformant recombinant clones containing a human gene that complements the Chinese hamster Gal-32 mutation and restores galactose metabolism.
authors.affiliation: Department of Biochemistry and Molecular Biology, Howard University, USA.
authors.forename: Zaki A
authors.initials: ZA
authors.lastname: Sherif
authors.affiliation: Howard University Cancer Center, USA.
authors.forename: Carolyn W
authors.initials: CW
authors.lastname: Broome
keywords: Chinese hamster; Cosmid vector; Gal 32; HeLa cell