- THIS ARTICLE
- Full Text (PDF)
- Alert me when this article is cited
- Alert me if a correction is posted
- SERVICES
- Similar articles in this journal
- Similar articles in PubMed
- Alert me to new issues of the journal
- Download to citation manager
- Reprints & Permissions
- CITING ARTICLES
- Citing Articles via HighWire
- Citing Articles via Google Scholar
- GOOGLE SCHOLAR
- Articles by Yang, D.
- Articles by Waldman, A. S.
- Search for Related Content
- PUBMED
- PubMed Citation
- Articles by Yang, D.
- Articles by Waldman, A. S.
Genetics, Vol 132, 1081-1093, Copyright © 1992
INVESTIGATIONS |
An Examination of the Effects of Double-Strand Breaks on Extrachromosomal Recombination in Mammalian Cells
D. Yang and A. S. Waldman
Walther Oncology Center and the Department of Biochemistry and Molecular Biology, Indiana University School of Medicine, Indianapolis, Indiana 46202
We studied the effects of double-strand breaks on intramolecular extrachromosomal homologous recombination in mammalian cells. Pairs of defective herpes thymidine kinase (tk) sequences were introduced into mouse Ltk(-) cells on a DNA molecule that also contained a neo gene under control of the SV40 early promoter/enhancer. With the majority of the constructs used, gene conversions or double crossovers, but not single crossovers, were recoverable. DNA was linearized with various restriction enzymes prior to transfection. Recombination events producing a functional tk gene were monitored by selecting for tk-positive colonies. For double-strand breaks placed outside of the region of homology, maximal recombination frequencies were measured when a break placed the two tk sequences downstream from the SV40 early promoter/enhancer. We observed no relationship between recombination frequency and either the distance between a break and the tk sequences or the distance between the tk sequences. The quantitative effects of the breaks appeared to depend on the degree of homology between the tk sequences. We also observed that inverted repeats recombined as efficiently as direct repeats. The data indicated that the breaks influenced recombination indirectly, perhaps by affecting the binding of a factor(s) to the SV40 promoter region which in turn stimulated or inhibited recombination of the tk sequences. Taken together, we believe that our results provide strong evidence for the existence of a pathway for extrachromosomal homologous recombination in mammalian cells that is distinct from single-strand annealing. We discuss the possibility that intrachromosomal and extrachromosomal recombination have mechanisms in common.
This article has been cited by other articles:
 |
|
 |
|
  C. A. Bill, W. A. Duran, N. R. Miselis, and J. A. Nickoloff Efficient Repair of All Types of Single-Base Mismatches in Recombination Intermediates in Chinese Hamster Ovary Cells: Competition Between Long-Patch and G-T Glycosylase-Mediated Repair of G-T Mismatches Genetics, August 1, 1998; 149(4): 1935 - 1943. [Abstract] [Full Text] [PDF]
|
|