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DNAs with unusual properties revealed by field inversion gel electrophoresis of agarose‐encapsulated DNA from mammalian cells
Author(s) -
Sukhova Tatjana,
Popenko Vladimir,
Serdjuk Ol'ga,
Alekhina Raisa,
Botezatu Irina,
Shelepov Valery,
Lichtenstein Anatoly
Publication year - 1998
Publication title -
febs letters
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.593
H-Index - 257
eISSN - 1873-3468
pISSN - 0014-5793
DOI - 10.1016/s0014-5793(98)00854-0
Subject(s) - dna , microbiology and biotechnology , chromatin , agarose , gel electrophoresis , lysis , electrophoresis , agarose gel electrophoresis , biology , gel electrophoresis of nucleic acids , chemistry , biochemistry
Distinct DNA fractions (fr‐DNAs), moving separately from bulk DNA, were revealed by field inversion gel electrophoresis of DNA from intact cells lysed and deproteinized in agarose plugs. These fr‐DNAs (∼2% of the total DNA) were ubiquitously present in nuclei of all mammalian cells studied, including human normal and tumor tissues, and showed a typical electrophoretic pattern (three bands with constant mobilities termed a ‐, b ‐, and c ‐DNA). Characteristic mobility shifts induced by gamma irradiation of a ‐ and b ‐DNAs suggest their non‐linear conformation. In fact, electron microscopy of a ‐ and b ‐DNAs from Namalwa cells revealed rosette‐like structures stabilized by a central protease‐resistant knob. Comparative PCR analysis revealed qualitative differences between genomic fingerprints of a ‐ and b ‐DNAs on the one hand and chromosomal DNA on the other. The results obtained suggest that fr‐DNAs originate either from some specific chromatin regions due to non‐random cleavages or from an autonomous intranuclear structure, not identified as yet.