Loading…
Involvement of Histone H3 (Ser10) Phosphorylation in Chromosome Condensation Without Cdc2 Kinase and Mitogen-Activated Protein Kinase Activation in Pig Oocytes
When oocytes resume meiosis, chromosomes start to condense and Cdc2 kinase becomes activated. However, recent findings show that the chromosome condensation does not always correlate with the Cdc2 kinase activity in pig oocytes. The objectives of this study were to examine 1) the correlation between...
Saved in:
Published in: | Biology of reproduction 2004-06, Vol.70 (6), p.1843-1851 |
---|---|
Main Authors: | , , |
Format: | Article |
Language: | English |
Subjects: | |
Online Access: | Get full text |
Tags: |
Add Tag
No Tags, Be the first to tag this record!
|
Summary: | When oocytes resume meiosis, chromosomes start to condense and Cdc2 kinase becomes activated. However, recent findings show
that the chromosome condensation does not always correlate with the Cdc2 kinase activity in pig oocytes. The objectives of
this study were to examine 1) the correlation between chromosome condensation and histone H3 phosphorylation at serine 10
(Ser10) during the meiotic maturation of pig oocytes and 2) the effects of protein phosphatase 1/2A (PP1/ PP2A) inhibitors
on the chromosome condensation and the involvement of Cdc2 kinase, MAP kinase, and histone H3 kinase in this process. The
phosphorylation of histone H3 (Ser10) was first detected in the clump of condensed chromosomes at the diakinesis stage and
was maintained until metaphase II. The kinase assay showed that histone H3 kinase activity was low in oocytes at the germinal
vesicle stage (GV) and increased at the diakinesis stage and that high activity was maintained until metaphase II. Treatment
of GV-oocytes with okadaic acid (OA) or calyculin-A (CL-A), the PP1/PP2A inhibitors, induced rapid chromosome condensation
with histone H3 (Ser10) phosphorylation after 2 h. Both histone H3 kinase and MAP kinase were activated in the treated oocytes,
although Cdc2 kinase was not activated. In the oocytes treated with CL-A and the MEK inhibitor U0126, neither Cdc2 kinase
nor MAP kinase were activated and no oocytes underwent germinal vesicle breakdown (GVBD), although histone H3 kinase was still
activated and the chromosomes condensed with histone H3 (Ser10) phosphorylation. These results suggest that the phosphorylation
of histone H3 (Ser10) occurs in condensed chromosomes during maturation in pig oocytes. Furthermore, the chromosome condensation
is correlated with histone H3 kinase activity but not with Cdc2 kinase and MAP kinase activities. |
---|---|
ISSN: | 0006-3363 1529-7268 |
DOI: | 10.1095/biolreprod.103.026070 |