Macronuclear transformation with specific DNA fragments controls the content of the new macronuclear genome in Paramecium tetraurelia. Academic Article uri icon


  • A previously isolated mutant cell line called d48 contains a complete copy of the A surface antigen gene in the micronuclear genome, but the gene is not incorporated into the macronucleus. Previous experiments have shown that a cytoplasmic factor made in the wild-type macronucleus can rescue the mutant. Recently, S. Koizumi and S. Kobayashi (Mol. Cell. Biol. 9:4398-4401, 1989) observed that injection of a plasmid containing the A gene into the d48 macronucleus rescued the cell line after autogamy. It is shown here that an 8.8-kb EcoRI fragment containing only a portion of the A gene coding region is sufficient for the rescue of d48. The inability of other A gene fragments to rescue the mutant shows that this effect is dependent upon specific Paramecium DNA sequences. Rescue results in restoration of the wild-type DNA restriction pattern in the macronucleus. These results are consistent with a model in which the macronuclear A locus normally makes an additional gene product that is required for correct processing of the micronuclear copy of the A gene.

published proceedings

  • Mol Cell Biol

author list (cited authors)

  • You, Y., Aufderheide, K., Morand, J., Rodkey, K., & Forney, J.

citation count

  • 1

complete list of authors

  • You, Y||Aufderheide, K||Morand, J||Rodkey, K||Forney, J

publication date

  • February 1991