Physiology of meiosis-activating sterol: endogenous formation and mode of action

Abstract

A rapid increase in FF-MAS level occurred in vivo in the rabbit ovary in response to LH, and clear differences were seen in the cAMP pattern during spontaneous and induced oocyte maturation in mice.

Autologous mature follicular fluid: its role in in vitro maturation of human cumulus-removed oocytes

“…This modification was mainly based on the accumulating evidence that human mature FF contains high levels of various components that are helpful for oocyte maturation and embryo development (18)(19)(20)(21)37). This modification was also based on the previous research results demonstrating that the promotion effects of human mature FF, as a heterologous or homologous supplement in the culture medium, on the meiotic resumption of mouse oocytes (22) and the IVM of human oocytes in the form of the cumulus-oocyte complex (24).…”

Principal findings from a multicenter trial investigating the safety of follicular-fluid meiosis-activating sterol for in vitro maturation of human cumulus-enclosed oocytes

“…Some components of the culture medium, including FF-MAS, are involved in driving the mechanisms that determine the speed of meiotic maturation (30). These mechanisms might be factors diffusing via transzonal projections, and triggering transduction systems driving the cell cycle (63,64).…”

Structural Basis of Human CYP51 Inhibition by Antifungal Azoles

“…14 CYP51 in mammals is also responsible for production of the follicular fluid (FF) meiosis-activating sterol (MAS). 15 Together with the testis MAS (T-MAS), the product of the downstream sterol Δ14-reductase reaction, these sterols are present at elevated levels in gonads 16,17 and are involved in oocyte maturation 18,19 and spermatogenesis. 20,21 While the importance of CYP51 activity in MASdependent gametogenesis and its mechanism is not fully understood, pharmacological applications for in vitro fertilization 22 and possibly the control of reproduction have been suggested.…”