Abstract

In the present experiments it has been possible to study large numbers of X-ray induced chromatid deletions, or breaks, in Chinese hamster chromosomes and to discern whether or not a sister chromatid exchange also occurs at the point of breakage. Chromatid deletions are only infrequently associated with a sister chromatid exchange. This is contrary to the expectations derived from the exchange hypothesis of Revell. On the basis of this hypothesis, in which chromatid deletions are considered to be incomplete exchanges that occur in the necks of little loops in the chromosomes, 40% of the chromatid breaks are expected to be associated with sister chromatid exchanges. The present data are in accord with the conclusions drawn from the earlier autoradiographic experiments of Heddle and Bodycote, and show that chromatid breaks can be accounted for on the basis of the breakage-and-reunion hypothesis, with the majority being simple breaks and some being incomplete exchanges between two such breaks.

Talk to us

Join us for a 30 min session where you can share your feedback and ask us any queries you have

Schedule a call

Disclaimer: All third-party content on this website/platform is and will remain the property of their respective owners and is provided on "as is" basis without any warranties, express or implied. Use of third-party content does not indicate any affiliation, sponsorship with or endorsement by them. Any references to third-party content is to identify the corresponding services and shall be considered fair use under The CopyrightLaw.