| Involvement
of MAPK in the Induction of Meiotic Maturation of Incompetent Oocytes
Lindsey
Heim
Luther
College
Decorah,
IA
Mentor:
Dr. Stephen Downs
At
birth, mouse oocytes are arrested in prophase I of meiosis. In fully grown
oocytes, the release of the oocyte from its surrounding follicular environment
results in the spontaneous resumption of meiosis, or meiotic maturation.
In contrast to these fully grown, competent oocytes, growing oocytes from
more immature stages of follicular development will not spontaneously resume
meiosis, and are designated as incompetent.
Although
incompetent oocytes do not resume meiosis spontaneously, they can be stimulated
to undergo maturation with various compounds. AICA riboside has been shown
in previous studies in this laboratory to stimulate meiotic maturation
in dbcAMP arrested compotent oocytes by the activation of AMPK, and it
is shown here that AICA riboside will also induce meiotic maturation in
incompetent oocytes. Additionally, it has been demonstrated that meiotic
maturation can be stimulated by activation of AMPK with rosiglitazone,
an anti-diabetic agent. Okadaic acid, a phosphatase inhibitor, stimulates
maturation in incompotent oocytes by the activation of mitogen-activated
protein kinase (MAPK). It is also shown here that by using the specific
inhibitors of MAPK, U0126 and PD98059, okadaic acid and AICA riboside induced
maturation can be partially inhibited. These results suggest a potential
role of MAPK activation in the meiotic maturation of incompetent oocytes. |
