MECHANISMS OF CHROMATID BREAKAGE IN HUMAN LYMPHOCYTE-CULTURES

  • 1 January 1977
    • journal article
    • research article
    • Vol. 21  (4) , 555-558
Abstract
G2 banding of human peripheral blood cultures with actinomycin D [AMD] and tetracycline produced chromatid breakage in lightly stained Giemsa bands, and the number of such breaks tended to increase with fixation time. Chromatid breakage due to 3H-thymidine incorporation into DNA was also localized in light bands, but the number of these breaks did not increase with fixation time. Modification of chromosomal protein as a result of exposure to AMD or other chemicals following DNA synthesis can result in fixative-dependent chromatid breakage of susceptible chromosomal regions, unlike breakage due to 3H-thymidine which primarily affects DNA and is not affected by fixation. Thus, chromatid breakage observed in short-term lymphocyte cultures is not necessarily evidence of mutagenicity involving DNA, but rather may be due to toxic effects on synthesis or attachment of chromosomal proteins.

This publication has 2 references indexed in Scilit: