In all eukaryotes, the ribosomal RNA genes are stably inherited redundant elements. In Drosophila melanogaster, the presence of a Ybb(-) chromosome in males, or the maternal presence of the Ribosomal exchange (Rex) element, induces magnification: a heritable increase of rDNA copy number. To date, several alternative classes of mechanisms have been proposed for magnification: in situ replication...

Toluene is widely used as an industrial solvent and is usually produced in the processes of making gasoline. Inhaled toluene may cause genotoxicity and other adverse health effects. This study aimed to ascertain the relation between blood toluene exposure and genotoxicity, as measured by sister chromatid exchange (SCE), by comparing gasoline station workers to controls. Mean blood toluene and S...

The sister chromatid exchange (SCE) frequencies of six freshly established and two old cell lines derived from patients with lymphatic tumors or leukemia were compared to the SCE rates of lymphoblastoid cell lines of normal controls. All cell lines from malignant tumors displayed significantly higher SCE values than the control lines. In general, the SCE rates seem to be correlated to the numbe...

The potential for genotoxic and cytotoxic effects of tolylfluanid-based fungicide (50% active agent) was evaluated using sister chromatid exchange (SCE) and proliferation indices (PI) in cultured bovine peripheral lymphocytes. For the detection of possible genetic damage, DNA fragmentation assay was also applied. Bovine lymphocytes cultured for 72 h were treated with the fungicide at the final ...

Telomeres are a hotspot for sister chromatid exchange (T-SCE). Any biological consequence of this form of instability remained obscure until quantitative modeling revealed a link between elevated T-SCE rates and accelerated cellular replicative senescence. This work strongly suggests that progressive telomere erosion is not the only determinant of replicative capacity; instead, T-SCE need to be...

ABSTRACT In this paper, I examine Louise Erdrich’s short story “Saint Marie (1934)” excerpted from her novel Love Medicine. The narrative, told from the perspective of Marie Lazarre, a young woman of mixed Chippewa Native American and “white” Anglo-American heritage, details the events of her time at the Sacred Heart Convent under the strict tutelage of Sister Leopolda where Marie undergoes sev...

Sister chromatid cohesion and chromosome condensation are both essential to the successful completion of mitosis. The recent identification and characterization of the yeast Mcd1p/Scc1p protein reveals a previously unsuspected mechanistic link between these processes.

The method of Matsumoto and Ohta [Matsumoto, K. & Ohta, T. (1992) Chromosoma 102, 60-65; Matsumoto, K. & Ohta, T. (1995) Mutat. Res. 326, 93-98] to induce large numbers of endoreduplicated Chinese hamster ovary cells has now been coupled with the fluorescence-plusGiemsa method of Perry and Wolff [Perry, P. & Wolff, S. (1974) Nature (London) 251, 156-158] to produce harlequin endoreduplicated ch...