Improvement in in?vitro fertilization outcome following in?vivo synchronization of oocyte maturation in mice

Synchronization of oocyte maturation in vitro has been shown to produce higher in vitro fertilization (IVF) rates than those observed in oocytes matured in vitro without synchronization. However, the increased IVF rates never exceeded those observed in oocytes matured in vivo without synchronization. This study was therefore designed to define the effect of in vivo synchronization of oocyte maturation on IVF rates. Mice were superovulated and orally treated with 7.5 mg cilostazol (CLZ), a phosphodiesterase 3A (PDE3A) inhibitor, to induce ovulation of immature oocytes at different stages depending on frequency and time of administration of CLZ. Mice treated with CLZ ovulated germinal vesicle (GV) or metaphase I (MI) oocytes that underwent maturation in vitro or in vivo (i.e. in the oviduct) followed by IVF. Superovulated control mice ovulated mature oocytes that underwent IVF directly upon collection. Ovulated MI oocytes matured in vitro or in vivo had similar maturation rates but significantly higher IVF rates, 2–4 cell embryos, than those observed in control oocytes. Ovulated GV oocytes matured in vitro showed similar maturation rates but significantly higher IVF rates than those observed in control oocytes. However, ovulated GV oocytes matured in vivo had significantly lower IVF rates than those noted in control oocytes. It is concluded that CLZ is able to synchronize oocyte maturation and improve IVF rates in superovulated mice. CLZ may be capable of showing similar effects in humans, especially since temporal arrest of human oocyte maturation with other PDE3A inhibitors in vitro was found to improve oocyte competence level. The capability of a clinically approved PDE3A inhibitor to improve oocyte fertilization rates in mice at doses extrapolated from human therapeutic doses suggests the potential scenario of the inclusion of CLZ in superovulation programs. This may improve IVF outcomes in infertile patients.     

Mouse phosphoinositide 3-kinase p110alpha gene: cloning, structural organization, and localization to chromosome 3 band B.

Phosphoinositide 3-Kinases (PI3-Kinases) are a family of dual specificity enzymes with a unique lipid kinase activity toward the D-3 position of the inositol ring of phosphoinositides and a less well characterized serine/threonine protein kinase activity. Class IA PI3-Kinases comprise a 110-120 kDa catalytic subunit (usually termed p110) and an 85 kDa or 50 to 55 kDa regulatory subunit (often called p85). cDNAs for three mammalian Class IA PI3-Kinase catalytic subunits designated p110alpha, p110beta, and p110delta have been cloned from several species. A YAC clone for the human p110alpha gene has also been cloned and mapped to chromosome 3q26.3. However, structural organization for any of the PI3-Kinase p110alpha genes has not been reported. Here, we report the cloning, structural organization, and chromosomal localization of the mouse PI3-Kinase p110alpha gene. The translated portion of the mouse p110alpha gene is encoded by 19 exons that span at least 24 kb. Dual color fluorescence in situ hybridization (FISH) was performed to determine the chromosomal localization of the mouse PI3-Kinase p110alpha gene. FISH results and DAPI banding demonstrated localization of the p110alpha gene to band B on mouse chromosome 3, a region syntenic with human chromosome 3q26.3.