Genetics, Vol 136, 1319-1324, Copyright © 1994


INVESTIGATIONS

The Role of Macronuclear DNA Sequences in the Permanent Rescue of a Non-Mendelian Mutation in Paramecium tetraurelia

Y. You, J. Scott and J. Forney
Department of Biochemistry, Purdue University, West Lafayette, Indiana 47907-1153

The Paramecium tetraurelia mutant called d48 has a complete copy of the A surface protein gene in its micronuclei, but lacks the A gene in the macronucleus. Previous experiments have shown that microinjection of a plasmid containing the entire A gene or a large portion of the gene into the macronucleus of d48 rescued the cell line after formation of a new macronucleus (autogamy). Here we show that several different regions of the A gene can rescue d48, but 100% of the activity cannot be localized to a single, defined region. Inversion of a sequence contained within an A gene plasmid had no measurable effect on rescue efficiency and co-injection of two different plasmids results in enhancement of rescue activity despite the non-contiguous form of the DNA sequences. Both these results suggest that no specific product (RNA or protein) with defined end points is made from the rescuing fragment. A unique restriction site was created in the A gene and used to demonstrate that the injected DNA does not serve as a direct template for the synthesis of the new macronuclear DNA. Models to explain the action of the injected DNA are discussed.


This article has been cited by other articles:


Home page
Eukaryot CellHome page
L. Amar and K. Dubrana
Epigenetic Control of Chromosome Breakage at the 5' End of Paramecium tetraurelia Gene A
Eukaryot. Cell, October 1, 2004; 3(5): 1136 - 1146.
[Abstract] [Full Text] [PDF]


Home page
Mol. Cell. Biol.Home page
O. Garnier, V. Serrano, S. Duharcourt, and E. Meyer
RNA-Mediated Programming of Developmental Genome Rearrangements in Paramecium tetraurelia
Mol. Cell. Biol., September 1, 2004; 24(17): 7370 - 7379.
[Abstract] [Full Text] [PDF]


Home page
Genes Dev.Home page
S Duharcourt, A Butler, and E Meyer
Epigenetic self-regulation of developmental excision of an internal eliminated sequence on Paramecium tetraurelia.
Genes & Dev., August 15, 1995; 9(16): 2065 - 2077.
[Abstract] [PDF]