Centromere spreading and out-of-phase chromatid separation in Burkitt's lymphoma and nasopharyngeal carcinoma.

Chromosomes with various degrees of centromere spreading and completely separated chromatids, as well as metaphasic chromosomes, were observed simultaneously in the same Burkitt's lymphoma cell. In another study, a pair of prematurely and completely separated chromatids was found in a metaphase of nasopharyngeal carcinoma cell. Based on these and other observations, the possible significance of centromere spreading and out-of-phase sister chromatid separation in the origin of chromosome nondisjunction in tumor cells is suggested and discussed.