CHROMATIN DIMINUTION IN NEMATODES

The process of chromatin diminution in Parascaris and Ascaris is a dev elopmentally controlled genome rearrangement, which results in quantit ative and qualitative differences in DNA content between germ line and somatic cells. Chromatin diminution involves chromosomal breakage, ne w telomere formation and DNA degradation. The programmed elimination o f chromatin in presomatic cells might serve as an alternative way of g ene regulation. We put forward a new hypothesis of how an ancient part ial genome duplication and chromatin diminution may have served to mai ntain the genetic balance in somatic cells and simultaneously endowed the germ line cells with a selective advantage.