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Co-culture with pig membrana granulosa cells modulates the activity of cdc2 and MAP kinase in maturing cattle oocytes.
- Source :
-
Zygote (Cambridge, England) [Zygote] 1996 Aug; Vol. 4 (3), pp. 247-56. - Publication Year :
- 1996
-
Abstract
- Bovine cumulus-enclosed oocytes, initially cultured up to diakinesis (8 h of initial culture) or metaphase I (12 h of initial culture), were subsequently co-cultured for 6 h in contact with pig membrana granulosa (PMG) cells and then assayed for histone H1 and MAP kinase activities. In addition, the phosphorylation state of ERK 1,2 proteins was determined by Western blotting. The alterations in nuclear envelope breakdown, meiotic spindle formation and the patterns of chromosome condensation were analysed by immunofluorescence and transmission electron microscopy. The diakinesis-stage oocytes (initially cultured for 8 h) already possessed high histone H1 kinase and MAP kinase activities that were correlated with condensed and partially individualised chromosomes. The ERK 1 and most ERK 2 proteins were partly phosphorylated. Following the 6 h co-culture of these oocytes with PMG a rapid decrease in MAP kinase activity and a slower decrease in histone H1 kinase occurred, as well as ERK 1 and ERK 2 dephosphorylation. Both kinase activities and ERK 1,2 phosphorylation were fully restored following the release of the oocytes from co-culture and a subsequent culture in the absence of PMG. Moreover, the clumped bivalents were reindividualised and 56% of these oocytes reached metaphase II after 20 h of culture without PMG. The metaphase I oocytes, initially cultured for 12 h, displayed a fusiform meiotic spindle and a metaphase array of chromosomal bivalents, accompanied by high levels of both histone H1 and MAP kinase activity. Co-culture of MI oocytes with PMG abolished the activity of both kinases and caused the dephosphorylation of ERK 1 and ERK 2. Furthermore, the spindle microtubules were depolymerised and the chromosomal bivalents clumped into a single mass. Neither of the protein kinase activities nor the meiotic spindle were restored following subsequent culture in the absence of PMG for up to 20 h. These observations indicate that under in vitro conditions membrana granulosa cells can cause a prompt decrease in histone H1 and MAP kinase activities, and metaphase I oocytes. While these events are fully reversible in late diakinesis oocytes, metaphase I oocytes did not complete maturation after release from co-culture.
- Subjects :
- Animals
Cattle
Chromosomes
Coculture Techniques
Female
Metaphase physiology
Microtubules
Mitogen-Activated Protein Kinase 1
Mitogen-Activated Protein Kinase 3
Nuclear Envelope metabolism
Oocytes cytology
Oocytes physiology
Phosphorylation
Protamine Kinase metabolism
Swine
CDC2 Protein Kinase metabolism
Calcium-Calmodulin-Dependent Protein Kinases metabolism
Granulosa Cells physiology
Meiosis physiology
Mitogen-Activated Protein Kinases
Oocytes enzymology
Subjects
Details
- Language :
- English
- ISSN :
- 0967-1994
- Volume :
- 4
- Issue :
- 3
- Database :
- MEDLINE
- Journal :
- Zygote (Cambridge, England)
- Publication Type :
- Academic Journal
- Accession number :
- 9117285
- Full Text :
- https://doi.org/10.1017/s0967199400003166