Oocyte

1
Granulosa cell
Pre LH Surge
Oocyte
ZP
LH receptor
LGR8 receptor
cAMP
Cumulus Cell
PKA (active)
2
Granulosa cell
LH
LH Surge
Oocyte
ZP
LH receptor
LGR8 receptor
INSL3 from thecal cells
Gai
EGF-like Growth Factors
cAMP
Adenyl Cyclase
EGF receptor
Ca
Connexin 37
Ca
cAMP Ca
Smooth ER
cAMP
AMP
cAMP
Connexin 43
PDE 4D gene
Gap Junction
PDE 3A
cAMP
Cumulus Cell
cAMP
PDE 3A gene
3
Granulosa cell
Low cAMP
LH
ZP
Oocyte
LH receptor
MAPK
LGR8 receptor
INSL3 from thecal cells
cMos
Cyclin B mRNA
Gai
EGF-like Growth Factors
Adenyl Cyclase
EGF receptor
Ca
Connexin 37
cAMP
Ca
phosphatase
phosphatase
Smooth ER
Cdc25 homolog (active)
Cdc25 homolog (inactive)
PDE 3A
Connexin 43 (phosphorylated And Degraded)
MAPK
PKC
cAMP
Gap Junctions Breakdown
R
C
Cumulus Cell
R
C
PKA (inactive)
PKA (active)
4
Active Maturation Promoting Factor
RNA Pol II
MAPK
Nucleolin NO38
RNA Pol II phosphorylation Inhibits transcription
pp60c-src
NO38 is involved in nucleolus disassembly
Active MAPK has many downstream targets
H1
pp60c-src phosphorylation leads to cytoskeletal
rearrangements necessary for GVBD and
metaphase plate formation
Lamin B phosphorylation breaks down the structure
of the germinal vesicle
Histone H1 phosphorylation leads to
chromatin condensation
Germinal Vesicle
RNA Pol II
Lamin B