TY - JOUR
T1 - Akt expression in mouse oocytes matured in vivo and in vitro
AU - Cecconi, Sandra
AU - Rossi, Gianna
AU - Santilli, Adriana
AU - Di Stefano, Leonardo
AU - Hoshino, Yumi
AU - Sato, Eimei
AU - Palmerini, Maria Grazia
AU - Macchiarelli, Guido
N1 - Funding Information:
The authors thank Professor Rita Canipari (University ‘La Sapienza’ Rome), for critical reading of the manuscript. This work was supported by MIUR (ex 60%, PRIN project) to S.C. This paper is dedicated to the victims of the earthquake of L’Aquila in April 2009.
PY - 2010/1
Y1 - 2010/1
N2 - To improve developmental competence of in vitro matured oocytes, culture medium can be supplemented with hypoxanthine (Hx) and FSH or epidermal growth factor (EGF) to trigger the activation of essential signalling pathways regulating meiotic resumption and progression. Since the serine/threonine kinase, Akt, contributes to the regulation of the meiotic cell cycle, this study analysed its expression level and localization at the meiotic spindle in oocytes matured in vivo or in vitro in the presence of Hx-FSH or Hx-EGF. Independently of culture conditions adopted, Akt mRNA concentration did not vary from germinal vesicle to metaphase I (MI), while at MII a significant decrease in Akt1 mRNA concentration was recorded in oocytes matured in vivo and in those stimulated by Hx-EGF (P<0.05). Phoshorylated Akt protein content was similar in the different groups of Ml oocytes, but it decreased at MII in oocytes matured either in vivo or in vitro with Hx-EGF. Ser-473-phosphorylated Akt was localized uniformly to the meiotic spindle in more than 90% of oocytes. These results indicate that, in mouse oocytes, Akt expression is differentially regulated during in vivo and in vitro maturation and suggest that EGF could be a positive modulator, even stronger than FSH, of oocyte meiotic maturation.
AB - To improve developmental competence of in vitro matured oocytes, culture medium can be supplemented with hypoxanthine (Hx) and FSH or epidermal growth factor (EGF) to trigger the activation of essential signalling pathways regulating meiotic resumption and progression. Since the serine/threonine kinase, Akt, contributes to the regulation of the meiotic cell cycle, this study analysed its expression level and localization at the meiotic spindle in oocytes matured in vivo or in vitro in the presence of Hx-FSH or Hx-EGF. Independently of culture conditions adopted, Akt mRNA concentration did not vary from germinal vesicle to metaphase I (MI), while at MII a significant decrease in Akt1 mRNA concentration was recorded in oocytes matured in vivo and in those stimulated by Hx-EGF (P<0.05). Phoshorylated Akt protein content was similar in the different groups of Ml oocytes, but it decreased at MII in oocytes matured either in vivo or in vitro with Hx-EGF. Ser-473-phosphorylated Akt was localized uniformly to the meiotic spindle in more than 90% of oocytes. These results indicate that, in mouse oocytes, Akt expression is differentially regulated during in vivo and in vitro maturation and suggest that EGF could be a positive modulator, even stronger than FSH, of oocyte meiotic maturation.
KW - Akt
KW - EGF
KW - FSH
KW - IVM
KW - Mouse
KW - Oocyte
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U2 - 10.1016/j.rbmo.2009.10.011
DO - 10.1016/j.rbmo.2009.10.011
M3 - Article
C2 - 20158985
AN - SCOPUS:77149154987
VL - 20
SP - 35
EP - 41
JO - Reproductive BioMedicine Online
JF - Reproductive BioMedicine Online
SN - 1472-6483
IS - 1
ER -