Document Type
Article
Language
eng
Publication Date
6-1989
Publisher
American Society for Microbiology
Source Publication
Molecular and Cellular Biology
Source ISSN
0270-7306
Original Item ID
doi: 10.1128/MCB.9.6.2598
Abstract
We have cloned two DNA fragments containing 5'-GATC-3' sites at which the adenine is methylated in the macronucleus of the ciliate Tetrahymena thermophila. Using these cloned fragments as molecular probes, we analyzed the maintenance of methylation patterns at two partially and two uniformly methylated sites. Our results suggest that a semiconservative copying model for maintenance of methylation is not sufficient to account for the methylation patterns we found during somatic growth of Tetrahymena. Although we detected hemimethylated molecules in macronuclear DNA, they were present in both replicating and nonreplicating DNA. In addition, we observed that a complex methylation pattern including partially methylated sites was maintained during vegetative growth. This required the activity of a methylase capable of recognizing and modifying sites specified by something other than hemimethylation. We suggest that a eucaryotic maintenance methylase may be capable of discriminating between potential methylation sites to ensure the inheritance of methylation patterns.
Recommended Citation
Capowski, Elizabeth E.; Wells, John M.; Harrison, Gail Singer; and Karrer, Kathleen M., "Molecular Analysis of N6-Methyladenine Patterns in Tetrahymena thermophila Nuclear DNA" (1989). Biological Sciences Faculty Research and Publications. 229.
https://epublications.marquette.edu/bio_fac/229
Comments
Published version. Molecular and Cellular Biology, Vol. 9, No. 6 (June 1989): 2598-2605. DOI. © 1989 American Society for Microbiology. Used with permission.
Kathleen Karrer was affiliated with Brandeis University at the time of publication.