OBJECTIVE To compare three different in vitro maturation (IVM) media for immature oocytes. DESIGN Experimental study. SETTING In vitro fertilization laboratory. ANIMAL(S) BDF1 female and male mice. INTERVENTION(S) Retrieval and maturation of cumulus-enclosed germinal vesicle-stage oocytes according to one of three protocols: group A, conventional IVM medium; group B, blastocyst culture ...

Cytoplasmic extracts of meiotically mature mouse oocytes were injected into immature Xenopus laevis oocytes, which underwent germinal vesicle breakdown within 2 h. Germinal vesicle breakdown was not inhibited by incubation of the Xenopus oocytes in cycloheximide (20 micrograms/ml). Identically prepared extracts of meiotically immature mouse oocytes, arrested at the germinal vesicle stage by dib...

We found that in starfish oocytes two different enzymes, phosphatidylserine synthase-1 (PSS1) and -2 (PSS2), which synthesize phosphatidylserine by a base-exchange reaction, are present. We studied phosphatidylserine synthesis in immature oocytes which still contain the nucleus (germinal vesicles) and in mature cells, in which the re-initiation of the meiotic cycle induced by the hormone 1-meth...

OBJECTIVE During stimulated IVF cycles, up to 15% of oocytes are recovered as immature. The purpose of this study was to investigate the trend of oocyte maturity in repeated ovarian stimulation for IVF. METHODS One hundred forty-eight patients were selected who underwent two consecutive IVF cycles using same stimulation protocol during 2008 to 2010. Ovarian stimulation was performed with FSH ...

BACKGROUND Vitrification has proven to be more effective than slow freezing methods to cryopreserve mammalian oocytes. The objectives of this study were to evaluate the effects of vitrification on immature and in vitro matured, denuded and cumulus compact goat oocytes and their subsequent fertilization. METHODS Oocytes were either cryopreserved as immature cumulus compact (IMCC) (n=98 Exp 1; ...

BACKGROUND/AIMS To observe the effects of vitrification on spindle, zona pellucida, embryonic aneuploidy and DNA injury in in vivo-maruted, in vitro-mature and immature human oocytes. METHODS Between January 2009 and February 2015, 223 immature oocytes from 450 infertile patients, and 31 in vivo-mature oocytes from 3 infertile couples were collected. Of the 223 immature oocytes, 113 were used...

The cryopreservation of immature GV oocytes by vitrification is offering attractive perspectives, since they represent an important pool of germ cells for women undergoing IVM cycles, or at risk of infertility for OHSS or PCOs, particularly those poor responders to gonadotropin stimulation, or in case of cancer. Therefore, it becomes necessary to optimize both cryopreservation technique as well...

Background: Cryopreservation of farm animal embryos is nowadays a widely used routine technique. Success in cryopreservation of form animal depends on many factors including: freezing medium, types of cryoproctants, melting process, lipid content in ooplasm and oocyte quality It has been found that immature Oocytes with reduced reproductive performance or slaughtered at the end of their use are...

BACKGROUND In vitro maturation (IVM) of immature oocytes collected from ovary has been proposed for fertility preservation. In addition, quality of oocytes post IVM is one of the factors determining its developmental competence. By using the non-invasive Polscope system, both meiotic spindle (MS) and zona pellucida (ZP) can be assessed in living oocytes. OBJECTIVE The aim was to investigate t...