Identification of the elemental packing unit of DNA in mammalian sperm cells by atomic force microscopy.

TitleIdentification of the elemental packing unit of DNA in mammalian sperm cells by atomic force microscopy.
Publication TypeJournal Article
Year of Publication1993
AuthorsHud, NV, Allen, MJ, Downing, KH, Lee, J, Balhorn, R
JournalBiochem Biophys Res Commun
Volume193
Issue3
Pagination1347-54
Date Published1993 Jun 30
ISSN0006-291X
KeywordsAnimals, Cattle, Cell Nucleus, Chromatin, Chromatography, High Pressure Liquid, DNA, Male, Microscopy, Electron, Protamines, Spectrophotometry, Atomic, Spermatozoa
Abstract

DNA is packaged within the sperm cell nuclei of many vertebrates and all mammals in a highly condensed state by small basic proteins (protamines). Despite continuous investigation for nearly half a century, the actual packing arrangement of the DNA has remained unresolved. Atomic force and electron microscopy studies described in this report provide evidence that the fundamental packing unit for sperm DNA is a toroidal structure, 900A in outside diameter with a 150A diameter hole, which contains up to 60kb of DNA. Although the results presented here are based primarily upon investigations of mammalian sperm cells, they are expected to be valid for all sperm cells which utilize protamines to package DNA.

DOI10.1006/bbrc.1993.1773
Alternate JournalBiochem. Biophys. Res. Commun.
PubMed ID8323555