dicentric chromosome

Dicentric chromosomes

    Physical breakage of the DNA molecule in two non-homologous chromosomes can produce "sticky ends" that recombine end-to-end (top right). The broken ends of the chromosomes lack centromeres, and are lost during cell division as acentric fragments. In a standard metaphase chromosome spread, the joined chromosomes are replicated and appear as a single chromosome with two centromeres. At mitosis or meiosis, the two centromeres may segregate together to the same pole so as to produce a product a more or less complete gene set. Alternatively, they may segregate to alternate poles, in which case the region between the two centromeres will be broken at random, and produce segmental aneuploidy in the daughter cells.

All text material ©2014 by Steven M. Carr