Imperfect Assortment

摘要

Cancer cells use multiple mechanisms to evade the normally stringent control on cell behaviors such as growth and differentiation. These mechanisms can involve chromosomal instability, a common occurrence in solid tumors whereby cells lose or gain whole chromosomes or parts thereof.rnUsing microarray-based methods to analyze with high resolution the chromosomal changes in individual cells, Vanneste et al. have observed that chromosomal instability occurs at a remarkably high frequency in human cleavage-stage embryos. In 2 of 23 3- to 4-day-old embryos from young healthy couples, all of the cells isolated contained normal chromosomes. The remainder contained various numbers of cells with extra whole chromosomes or chromosomal fragments. Although this study analyzed embryos generated by in vitro fertilization, there may be in vivo implications, given that half of spontaneous abortions display chromosomal imbalances.