DNA REPLICATION PATTERNS AND CHROMOSOMAL PROTEIN SYNTHESIS IN OPOSSUM LYMPHOCYTES IN VITRO

DNA replication patterns were determined in the autosomes and sex chromosomes of phytohemagglutinin-stimulated lymphocytes from the opossum (Didelphis virginiana) by employing thymidine-3H labeling and high-resolution radioautography. Opossum chromosomes are desirable experimental material due to t...

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Main Authors:	Schneider, Lawrence K., Rieke, William O.
Format:	Online
Language:	English
Published:	The Rockefeller University Press 1967
Online Access:	https://www.ncbi.nlm.nih.gov/pmc/articles/PMC2107208/

id	pubmed-2107208
recordtype	oai_dc
spelling	pubmed-21072082008-05-01 DNA REPLICATION PATTERNS AND CHROMOSOMAL PROTEIN SYNTHESIS IN OPOSSUM LYMPHOCYTES IN VITRO Schneider, Lawrence K. Rieke, William O. Article DNA replication patterns were determined in the autosomes and sex chromosomes of phytohemagglutinin-stimulated lymphocytes from the opossum (Didelphis virginiana) by employing thymidine-3H labeling and high-resolution radioautography. Opossum chromosomes are desirable experimental material due to their large size, low number (2n = 22), and morphologically distinct sex chromosomes. The autosomes in both sexes began DNA synthesis synchronously and terminated replication asynchronously. One female X chromosome synthesized DNA throughout most of the S phase. Its homologue, however, began replication approximately 3.5 hr later. The two X's terminated DNA synthesis synchronously, slightly later than the autosomes. This form of late replication, in which one X chromosome begins DNA synthesis later than its homologue but completes replication at the same time as its homologue, is apparently unique in the opossum. The male X synthesized DNA throughout S while the Y chromosome exhibited late-replicating characteristics. The two sex chromosomes completed synthesis synchronously, slightly later than the autosomes. Grain counts were performed on all chromosomes to analyze trends in labeling intensity at hourly intervals of S. By analyzing the percent of labeled mitotic figures on radioautographs at various intervals after introduction of arginine-3H, chromosomal protein synthesis was found not to be restricted to any portion of interphase but to increase throughout S and into G2. The Rockefeller University Press 1967-06-01 /pmc/articles/PMC2107208/ /pubmed/6036519 Text en Copyright © 1967 by The Rockefeller University Press This article is distributed under the terms of an Attribution–Noncommercial–Share Alike–No Mirror Sites license for the first six months after the publication date (see http://www.rupress.org/terms). After six months it is available under a Creative Commons License (Attribution–Noncommercial–Share Alike 4.0 Unported license, as described at http://creativecommons.org/licenses/by-nc-sa/4.0/).
repository_type	Open Access Journal
institution_category	Foreign Institution
institution	US National Center for Biotechnology Information
building	NCBI PubMed
collection	Online Access
language	English
format	Online
author	Schneider, Lawrence K. Rieke, William O.
spellingShingle	Schneider, Lawrence K. Rieke, William O. DNA REPLICATION PATTERNS AND CHROMOSOMAL PROTEIN SYNTHESIS IN OPOSSUM LYMPHOCYTES IN VITRO
author_facet	Schneider, Lawrence K. Rieke, William O.
author_sort	Schneider, Lawrence K.
title	DNA REPLICATION PATTERNS AND CHROMOSOMAL PROTEIN SYNTHESIS IN OPOSSUM LYMPHOCYTES IN VITRO
title_short	DNA REPLICATION PATTERNS AND CHROMOSOMAL PROTEIN SYNTHESIS IN OPOSSUM LYMPHOCYTES IN VITRO
title_full	DNA REPLICATION PATTERNS AND CHROMOSOMAL PROTEIN SYNTHESIS IN OPOSSUM LYMPHOCYTES IN VITRO
title_fullStr	DNA REPLICATION PATTERNS AND CHROMOSOMAL PROTEIN SYNTHESIS IN OPOSSUM LYMPHOCYTES IN VITRO
title_full_unstemmed	DNA REPLICATION PATTERNS AND CHROMOSOMAL PROTEIN SYNTHESIS IN OPOSSUM LYMPHOCYTES IN VITRO
title_sort	dna replication patterns and chromosomal protein synthesis in opossum lymphocytes in vitro
description	DNA replication patterns were determined in the autosomes and sex chromosomes of phytohemagglutinin-stimulated lymphocytes from the opossum (Didelphis virginiana) by employing thymidine-3H labeling and high-resolution radioautography. Opossum chromosomes are desirable experimental material due to their large size, low number (2n = 22), and morphologically distinct sex chromosomes. The autosomes in both sexes began DNA synthesis synchronously and terminated replication asynchronously. One female X chromosome synthesized DNA throughout most of the S phase. Its homologue, however, began replication approximately 3.5 hr later. The two X's terminated DNA synthesis synchronously, slightly later than the autosomes. This form of late replication, in which one X chromosome begins DNA synthesis later than its homologue but completes replication at the same time as its homologue, is apparently unique in the opossum. The male X synthesized DNA throughout S while the Y chromosome exhibited late-replicating characteristics. The two sex chromosomes completed synthesis synchronously, slightly later than the autosomes. Grain counts were performed on all chromosomes to analyze trends in labeling intensity at hourly intervals of S. By analyzing the percent of labeled mitotic figures on radioautographs at various intervals after introduction of arginine-3H, chromosomal protein synthesis was found not to be restricted to any portion of interphase but to increase throughout S and into G2.
publisher	The Rockefeller University Press
publishDate	1967
url	https://www.ncbi.nlm.nih.gov/pmc/articles/PMC2107208/
_version_	1611409369517260800

DNA REPLICATION PATTERNS AND CHROMOSOMAL PROTEIN SYNTHESIS IN OPOSSUM LYMPHOCYTES IN VITRO

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