[Localization of satellite DNA and associated protein in respect to nucleolar precursor bodies in one- and two-cell mouse embryos].

Nucleolar precursor bodies (NPB) are characteristic structures in the nuclei of one- and two cell mouse embryos. The alignment of centromeric (CEN) and pericentromeric (periCEN) chromosome regions to the chromatin layer surrounding NPB is known. Mus musculus 4 satellite DNA (satDNA) types are known to be located in CEN region--mouse minor satellite (MiSat) and mouse satellite 3 (MS3); and periCEN region--mouse major satellite (MaSat) and mouse satellite (MS4).

[DNA of some regions of constitutive heterochromatin is demethylated and decondensed in MRC5 and A431 cells].

It is believed that satellite DNA is compact and transcriptionally inert during interphase. We determined localization, range of compactization and methylation state of the centromeric and pericentromeric satellite DNA using the method of fluorescence hybridization in situ (FISH) combined with the antibody immunostaining against the methylated DNA. We investigated the tissue cells (the cells of placenta and lymphocytes), primary (MRC5 fibroblasts) and malignant (A431) cell cultures.

[Multifunctional nuclear protein NAP57 specifically interacts with dead RNA-helicase p68].

NAP57 has been found as a component of nuclear matrix protein complex with ability to specifically bind alphoid DNA. Polyclonal antibodies against NAP57 were raised in order to investigate intranuclear localization and interactions of the protein. Two types of localization were observed: a) nucleoplasmic and b) nucleolar.

[Position of the satellite DNA relative to heterochromatin in the interphase nuclei in cultured cells].

It is considered that centromeric (CEN) regions play the leading role in the formation of chromocentres predominantly consisting of satellite DNA. Cloned mouse and human satellite DNA sequences from CEN and periGEN regions were used in order to trace their positions relative to chromocentres. Methods of fluorescent in situ hybridization (FISH) and immunoFISH with antibodies against CENP-B, known is a marker of prekinetochore, were employed.

[The mammalian centromere organization].

Routine and recently obtained data on the pattern and functions of the mammalian centromeres and kinetochores have been reviewed. Several problems of kinetochore formation (centromere recognition, anaphase checkpoint) are specially discussed, in addition to the role played by centromere DNA in the interphase nucleus consideration.