Fusions near telomeres occur very early in the amplification of CAD genes in Syrian hamster cells.

Spontaneous differentiated squamous cell carcinoma of cheek pouch in a Syrian hamster

A 2-year-old male hamster was presented because of left facial swelling and salivation. Necropsy wasperformed and affected cheek pouch with tissue samples of regional and internal organs were submitted forhistopathological study. In histopathological examination it was found that the tumor consisted of cords andislands of tumoric epithelial cells which were diffused in the dermis. Vacoulation o...

Rap1 prevents telomere fusions by nonhomologous end joining.

Telomeres protect chromosomes from end-to-end fusions. In yeast Saccharomyces cerevisiae, the protein Rap1 directly binds telomeric DNA. Here, we use a new conditional allele of RAP1 and show that Rap1 loss results in frequent fusions between telomeres. Analysis of the fusion point with restriction enzymes indicates that fusions occur between telomeres of near wild-type length. Telomere fusions...

Distribution of the serum proteins of Syrian hamster as revealed by Starch gel electrophoresis

A qualitative and quantitative assay for cells lacking postconfluence inhibition of cell division: characterization of this phenotype in carcinogen-treated Syrian hamster embryo cells in culture.

We have developed a qualitative and quantitative assay system for detecting cells lacking postconfluence inhibition of cell division (contact insensitivity, CS-) in golden Syrian hamster embryo cells in culture by measuring the number of cells able to form colonies on a lethally irradiated, confluent monolayer of a contact-sensitive established cell line. A subpopulation in normal low-passage c...

Five dysfunctional telomeres predict onset of senescence in human cells

Replicative senescence is accompanied by a telomere-specific DNA damage response (DDR). We found that DDR+ telomeres occur spontaneously in early-passage normal human cells and increase in number with increasing cumulative cell divisions. DDR+ telomeres at replicative senescence retain TRF2 and RAP1 proteins, are not associated with end-to-end fusions and mostly result from strand-independent, ...