In-vitro maturation of oocytes: biological aspects

Could oxidative stress influence the in-vitro maturation of oocytes?

“…IVM constitutes the in-vitro advancement of an oocyte from the diplotene stage of prophase I (germinal vesicle, or GV) to metaphase II (MII), along with cytoplasmic maturation that encompasses a broad set of still ill-defined cellular events, all of which are essential for the fertilization and early development of the embryo (Smitz et al , 2001; Trounson et al , 2001; Ali et al , 2006). Arising from a growing pool of antral follicles, a number of oocytes are typically retrieved and available for IVM treatment.…”

“…Multiple investigators have tapped the various aspects of the IVM process to determine the sequence of changes that take place in the oocyte as well as the factors that influence them. Over the years, the majority of research findings conclude that successful IVM necessitates not only nuclear but also cytoplasmic maturation (Fulka et al , 1998; Smith, 2001; Ali et al , 2006). In vivo , oocyte maturation is a complex process that is influenced by the interplay of regulatory factors (among which are gonadotrophins and a growing list of secreted molecules), interactions between the oocyte and cumulus cells, and the biochemical state of the oocyte (Canipari, 2000; Eppig, 2001; Tanghe et al , 2002; Combelles et al , 2004; Gilchrist et al , 2004).…”

“…In vivo , oocyte maturation is a complex process that is influenced by the interplay of regulatory factors (among which are gonadotrophins and a growing list of secreted molecules), interactions between the oocyte and cumulus cells, and the biochemical state of the oocyte (Canipari, 2000; Eppig, 2001; Tanghe et al , 2002; Combelles et al , 2004; Gilchrist et al , 2004). Much success has been achieved in terms of successful nuclear maturation in vitro but the cytoplasmic maturation lags behind, thereby reflecting an asynchrony between the two processes (Smith, 2001; Trounson et al , 2001; Ali et al , 2006). In an effort to simulate the in-vivo conditions that prevail in the pre-ovulatory antral follicle, a plethora of human studies have tested different formulations of culture media; to date, varied (and overall disappointing) results have been obtained in terms of human oocyte maturation, fertilization and pregnancy outcomes post IVM (Smitz et al , 2001; Chian et al , 2004b; Mikkelsen, 2005).…”

Influence of well defined protein source on in vitro maturation of human oocyte: human follicular fluid versus human serum albumin

“…Although FF supplementation of IVM medium has been proven to provide a beneficial microenvironment for further development of the immature oocyte (11) and hFF has commonly been added to the maturation media as an exogenous protein source, it is a highly undefined supplement and has a risk of contamination. There has been a trend in recent years to use more defined components which have no batchto-batch variability or risk of contamination (12).…”

Mos 3′ UTR regulatory differences underlie species‐specific temporal patterns of Mos mRNA cytoplasmic polyadenylation and translational recruitment during oocyte maturation

“…Current in vitro fertilization (IVF) regimes employ in vivo matured oocytes or in vitro maturation of aspirated GV positive oocytes, though both sources of oocytes present inherent limitations (Chian et al, 2004; Ali et al, 2006). The success of IVF protocols with in vivo matured oocytes has a significant dependency on the age of the oocyte donor where successful fertility outcomes decrease with age (Krey et al, 2001), while in vitro human oocyte maturation is associated with a loss of developmental competence as indicated by the reduction or absence of specific proteins in oocytes cultured to metaphase II (Moor et al, 1998; Trounson et al, 2001).…”