Comparison of chromosome associations in human lymphocytes arrested by colcemid, nocodazole, or cycloheximide

The method of "generalized distances" was applied to compare the effects on homologous interchromosomal distances of colcemid, the routinely used tubulin inhibitor with the effects of two other metaphase arrestants: nocodazole, also a tubulin inhibitor and cycloheximide, an inhibitor of protein synthesis which preserves somatic association. More homologous pairs were associated in the cycloheximide treatment than in the other two procedures; however, while several chromosomes which tend to lie toward the center of the metaphase plate showed somatic association in the various treatments, we found no evidence for somatic association of the larger, more peripherally located chromosomes in human cells in any of our treatments (chromosome pair 7 excepted in the colcemid sample).