HALF-CHROMATID ABERRATIONS AND CHROMOSOME STRANDEDNESS

Abstract

If cells are irradiated during prophase, at anaphase they may show a side-arm bridge type of configuration. These have usually been interpreted as half-chromatid aberrations and they have been used as evidence that chromosomes are multistranded. It is the purpose of this paper to emphasize that such a configuration may just as easily arise on the basis of a single-stranded chromosome, and that the data on the type of aberrations found at the next mitosis (M2) suggest that chromosomes are single-stranded.