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Replication bands and nucleoli in the macronucleus of Euplotes eurystomus : An ultrastructural and cytochemical study
Author(s) -
Olins Ada L.,
Olins Donald E.,
Derenzini Massimo,
HernandezVerdun Danièle,
Gou Pierre,
RobertNicoud Michel,
Jovin Thomas M.
Publication year - 1988
Publication title -
biology of the cell
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.543
H-Index - 85
eISSN - 1768-322X
pISSN - 0248-4900
DOI - 10.1111/j.1768-322x.1988.tb00708.x
Subject(s) - nucleolus , macronucleus , biology , osmium , chromatin , ultrastructure , dna , organelle , microbiology and biotechnology , biophysics , dna replication , biochemistry , cytoplasm , anatomy , ruthenium , catalysis
The principal structural compartments of the macronucleus of Euplotes eurystomus were examined by ultrastructural and cytochemical procedures. Interphase chromatin is condensed in highly compact granules that stain intensely with the DNA‐specific osmium‐amine procedure. Nucleoli react strongly with silver and with thiol‐specific reagents, but are almost completely unstained by osmium‐amine. The organelle of DNA synthesis, the replication band, is composed of 2 zones. The forward zone consists of highly ordered chromatin fibers, stains strongly with osmium‐amine, with silver, and with thiol‐specific reagents. The rear zone, which is the site of DNA synthesis, is impoverished in DNA, and is very sensitive to collapse induced by in vivo heat shock, or during nuclear isolation.