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

Autor: Gavrilova, E., Kuznetsova, I., Enukashvily, N., Noniashvili, E., Dyban, A., Podgornaya, O.
Zdroj: Cell & Tissue Biology; Jun2009, Vol. 3 Issue 3, p213-221, 9p
Abstrakt: Nucleolar precursor bodies (NPB) are discrete entities in zygotic pronuclei and in the nuclei of two-cell mouse embryos. Centromeric (CEN) and pericentromeric (periCEN) chromosome regions are associated with the chromatin layer surrounding NPB. Four types of satellite DNA (satDNA) are currently known in Mus musculus, including mouse minor satellite 4 (MiSat), mouse satellite 3 (MS3) in the CEN region, mouse major satellite (MaSat), and mouse satellite (MS4) in the periCEN region. We determined the localization of these four types of mouse satDNA and associated proteins (RNA-helicase p68, SMC3, Rad21 subunits of the cohesin complex and SYCP3 subunit of the synaptonemal complex) in respect to NPB. Partially flattened nuclei of the one- and two-cell intact embryos and embryos treated with okadaic acid (OA) were used. It was found that different satDNA are localized in different regions at the NPB surface: periCEN MaSat occupied almost the whole NPB surface; CEN MiSat, MS3 and periCEN MS4 were located more peripherally. All four satDNA did not cover the entire NPB area, which indicates the presence of other DNA sequences involved in the association with NPB periphery. Among the proteins probed, RNA-helicase p68 and components of multiprotein cohesin and synaptonemal complexes (SCs) showed the most prominent colocolization with NPB. Our results support the idea that NPB are chromocenter precursors. [ABSTRACT FROM AUTHOR]
Databáze: Complementary Index
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