Biological effects of a bifunctional DNA crosslinker - I. Generation of triradial and quadriradial chromosomes

Interduplex crosslinks by a bifunctional anthramycin DNA crosslinker produc ed triradial and quadriradial chromosomes. The crosslinker alkylates guanin e at N-2, Bovine chromosomes contain GC-rich density satellite DNAs at the centromeric heterochromatin and is the basis for the formation of triradial and quadriradial chromosomes at the centromeres, The in situ crosslinking of interphase chromosomes indicates that the distance between centromeres i s 17.5 Angstrom. We conclude that the nuclear matrix associated DNA in the centromeric heterochromatin of interphase chromosomes are positioned close enough for crosslinking to occur. We propose a model for the generation of triradial and quadriradial chromosomes based upon the number of interduplex crosslinks between two chromosomes. (C) 1999 Elsevier Science B.V, All rig hts reserved.