Transformation of tetrahymena thermophila with hypermethylated rRNA genes

Journal Article · Fri Apr 01 04:00:00 EST 1988 · Mol. Cell. Biol.; (United States)

DOI:https://doi.org/10.1128/MCB.8.4.1664· OSTI ID:7143997

Karrer, K M; Yao, M C

The extrachromosomal rRNA genes (rDNA) of Tetrahymena thermophila contain 0.4% N/sup 6/-methyladenine. C3 strain rDNA was isolated, hypermethylated in vitro, and microinjected into B strain host cells. Clonal cell lines were established, and transformants were selected on the basis of resistance to paromomycin, conferred by the injected rDNA. The effects of methylation by three enzymes which methylate the sequence 5'-NAT-3'', the dam, EcoRI, and ClaI methylases, were tested. Hypermethylation of the injected rDNA had no effect on transformation efficiency relative to mock-methylated controls. The injected C3 strain rDNA efficiently replaced host rDNA as the major constituent of the population of rDNA molecules. Hypermethylation of the injected DNA was not maintained through 20 to 25 cell generations.

• Research Organization: Dept. of Biology, Brandeis Univ., Waltham, MA (US)
• OSTI ID: 7143997
• Journal Information: Mol. Cell. Biol.; (United States), Journal Name: Mol. Cell. Biol.; (United States) Vol. 8:4; ISSN MCEBD
• Country of Publication: United States
• Language: English

Related Subjects

550200* -- Biochemistry
550400 -- Genetics
59 BASIC BIOLOGICAL SCIENCES
ANIMALS
CELL CULTURES
CHEMICAL REACTIONS
CILIATA
CLONE CELLS
DRUGS
ENZYME ACTIVITY
GENES
GENETIC ENGINEERING
IN VITRO
INVERTEBRATES
METHYLATION
MICROORGANISMS
MUTANTS
NUCLEIC ACIDS
ORGANIC COMPOUNDS
PROTOZOA
RIBOSOMAL RNA
RNA
SENSITIVITY
TETRAHYMENA