ORGANIZATION OF CENTROMERE REGIONS OF CHROMOSOMES IN THE LAMPBRUSH PHASE
A. V. Krasikova, E. R. Gaginskaya 1
Laboratory of Chromosome Structure and Function, St. Petersburg State University;
1 e-mail: spbchromas@gmail.com
Centromeres have a pivotal role in the complex of structural elements that are required for precise segregation
of eukaryotic chromosomes during two types of cellular divisions — mitosis and meiosis. Data of ultrastructural
and cytomolecular analysis indicate significant changes in molecular composition and functional morphology
of centromeres during preparation for the first meiotic division. The review is devoted to modern concepts
of morpho-functional organization of chromosomal centromere regions in growing oocytes in birds and
amphibians. Structure, molecular composition as well as domain organization of centromeres in the lampbrush
phase are characterized; data of cytogenetic analysis are presented. Special attention is given to the significance
and regulation of satellite DNA transcription in the nuclei of developing oocytes. Possible functions of centromere
«protein bodies» formed at the primary constriction of meiotic bivalents are discussed.
Key words: centromere, centromere protein bodies, genome architecture, heterochromatin, lampbrush
chromosomes, non-coding RNA, oocyte, satellite DNA
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