Abstracts (poster) - Wissenschaft Online

Maciej Meglicki, Marta Teperek, Ewa Borsuk
Localization of heterochromatin protein 1α during mouse
oogenesis and early embryonic development
Proper organization of pericentric heterochromatin is vital for proper chromosome
segregation and for the maintenance of genome stability in eukaryotic cells. The
structure of pericentric heterochromatin depends mainly on presence of certain histone
variants, non-histone proteins and specific pattern of epigenetic modifications of core
histones. One of the non-histone proteins, which is thought to be indispensable for the
formation and maintenance of heterochromatin, is HP1 (heterochromatin protein 1). Two
isoforms of HP1, HP1α and HP1β, have been found at pericentric regions of somatic cells
at interphase. In these cells, HP1β and majority of HP1α dissociate into the cytoplasm
before prometaphase and re-associate with pericentric regions at the end of mitosis.
Localization of HP1α in mouse oocytes and early embryos was unknown.
Here we show localization of HP1α protein during oogenesis and in cleaving mouse
embryos. HP1α was not detected in primordial oocytes. It appeared in pericentric
heterochromatin at the beginning of the growth phase. Subsequently, it dissociated from
these regions in fully-grown oocytes during cessation of transcription and was absent in
maturing and ovulated oocytes. It was not observed in zygotes, but reappeared in 2-cell
embryos. At this stage and in 4- and 8-cell embryos, the association of HP1α with
pericentric heterochromatin was restricted to defined stages of the interphase (S/G2).
Literature
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122:1008-1022
contact:
M.Sc Maciej Meglicki
University of Warsaw
Zoology
mmeglicki@biol.uw.edu.pl
ul. Przy Agorze 28
01-930 Warsaw (Poland)