G.A. Wyngaard and T.R. Gregory
Journal of Experimental Zoology (Molecular and Developmental
Evolution)
291: 310-316.
Abstract
Chromatin diminution is a precisely controlled, highly repeatable,
genome-wide
deletion of non-coding heterochromatic segments from the presomatic
line.
The somatic line is reduced in size and reorganized; the germ line
remains
unaltered. Little is understood about its mechanistic underpinnings and
adaptive significance in the nematodes, copepods, and hagfish in which
it occurs. Here, we propose that microcrustacean copepods, whose
cytology, development, and evolutionary ecology are well understood
from
an adaptationist point of view, provide the vehicle to test how
chromatin
diminution might orchestrate certain cell cycle dynamics, with the
consequence
of influencing the evolution of nuclear DNA contents, organismal
development
rates, and body size.