45S rDNA Regions Are Chromosome Fragile Sites Expressed as Gaps In Vitro on Metaphase Chromosomes of Root-Tip Meristematic Cells in Lolium spp

摘要

BackgroundIn humans, chromosome fragile sites are regions that are especially prone to forming non-staining gaps, constrictions or breaks in one or both of the chromatids on metaphase chromosomes either spontaneously or following partial inhibition of DNA synthesis and have been well identified. So far, no plant chromosome fragile sites similar to those in human chromosomes have been reported.