Zbornik - Društvo genetičara Srbije

44 ZBORNIK ABSTRAKATA III KONGRESA GENETIÈARA SRBIJE II-Uvo-1
Subotica, 30. novembar - 4. decembar 2004.
SINGLE CELL GEL ELECTROPHORESIS (SCGE) OR COMET ASSAY
AS A METHOD FOR ASSESSING THE ROLES OF LINKER HISTONE H1
IN CHROMATIN
M. Kirilova and G. Miloshev
Yeast Molecular Genetics Laboratory, Institute of Molecular Biology,
Bulgarian Academy of Sciences, Sofia
Chromatin is the basic structure in which DNA is organized in the cell nucleus. Activity
of the genes relays not only on the upstream/downstream regulating sequences and transcription
factors but also is deeply affected by the way in which DNA is packaged with
the chromatin proteins. Chromatin is composed predominantly of DNA and four core
histones H2, H2B, H3 and H4. All four histones through their post-translational modifications
play an important role in the regulation of genome function. The fifth histone, H1
is involved in the organizing the higher-order chromatin structures and presumably also
in the fine regulation of gene activity. However, how and where in the cell cycle this role
is accomplished remains mostly obscure.
Here we present our current results in application of the Comet assay, a method initially
developed for assessing DNA damages, for the revealing differences in chromatin structure.
We modified the classical Comet assay by applying it on yeast and developing the
Yeast Comet Assay (YCA). Application of YCA to chromatin research demonstrated
that histone H1 in yeast partially protects DNA in nucleus from digestion with nucleases
and may be involved in presumable contacts of the chromatin with nuclear matrix.