COMPUTER-GRAPHICS OF SEM IMAGES FACILITATE RECOGNITION OF CHROMOSOME POSITION IN ISOLATED HUMAN METAPHASE PLATES

There is general agreement that at the time of mitosis chromosomes occ upy precise positions and that these positions likely affect subsequen t nuclear function in interphase. However, before such ideas can be in vestigated in human cells, it is necessary to determine first the prec ise position of each chromosome with regard to its neighbors. It has o ccurred to us that stereo images, produced by scanning electron micros copy, of isolated metaphase plates could form the basis whereby these positions could be ascertained. In this paper we describe a computer g raphic technique that permits us to keep track of individual chromosom es in a metaphase plate and to compare chromosome positions in differe nt metaphase plates. Moreover, the computer graphics provide permanent , easily manipulated, rapid recall of stored chromosome profiles. Thes e advantages are demonstrated by a comparison of the relative position of group A-specific and groups D- and G-specific chromosomes to the f ull complement of chromosomes in metaphase plates isolated from a near ly triploid human-derived cell (HeLa S-3) to a hypo-diploid human feta l lung cell. (C) 1995 Wiley-Liss, Inc.