Increased sister chromatid exchanges in human cell lines characterized by monosomy X or structural abnormalities of the X chromosome.
In the present investigation we test the hypothesis that deficiencies of the X chromosome affect sister chromatid exchange (SCE) frequencies in human fibroblast cell lines. Our results show increased mean SCE frequencies in cell lines with abnormalities of the X chromosome: 45,X; 46,X,del(X) (q13), 46,X,del(X)(p11), and 46,X,i(Xq); control cell lines were 46,XX. In only one abnormal line [46,X,del(X)(p11)] was the increase not significant after correcting for multiple comparisons. If SCE formation is replication-dependent, the increased SCE frequencies might merely reflect the prolonged cell cycle we reported previously in cell lines with X chromosome abnormalities (Simpson and LeBeau 1981). Other explanations for differences between cell lines are possible, e.g., that deleted loci on the X chromosome affect cellular uptake of bromodeoxyuridine (BrDU). However, specific mechanisms were not explored directly.
D000328:Adult; D002460:Cell Line; D005260:Female; D006801:Humans; D009006:Monosomy; D012729:Sex Chromosome Aberrations / Q000235:genetics*; D012854:Sister Chromatid Exchange; D012867:Skin / Q000166:cytology; D014960:X Chromosome / Q000502:physiology*