Pgrmc1 Knockout Impairs Oocyte Maturation in Zebrafish

Area of Science:

• Reproductive Biology
• Molecular Endocrinology
• Zebrafish Models

Background:

• Progestin receptor membrane component 1 (PGRMC1) is implicated in transporting various molecules, including receptors and signaling proteins.
• Distinguishing PGRMC1's specific functions from its associated molecules has been challenging using traditional biochemical methods.

Purpose of the Study:

• To elucidate the physiological roles of PGRMC1 in vivo.
• To investigate PGRMC1's function in female reproductive processes, specifically oocyte maturation and fertility in zebrafish.

Main Methods:

• Generation of global pgrmc1 knockout zebrafish (pgrmc1^-/-).
• Assessment of reproductive parameters: spawning frequency and embryo production.
• Evaluation of oocyte meiotic maturation in vivo and in vitro, and measurement of mPRα expression.

Main Results:

• pgrmc1^-/- female zebrafish exhibited reduced spawning frequency and fewer embryos.
• Mutant oocytes showed decreased sensitivity to progestin hormones, leading to impaired meiotic maturation.
• Reduced expression of membrane progestin receptor alpha (mPRα) was observed in pgrmc1^-/- oocytes.

Conclusions:

• PGRMC1 plays a vital physiological role in regulating oocyte maturation and fertility in zebrafish.
• PGRMC1 influences fertility likely through the regulation of mPRα expression, which is critical for meiosis resumption.
• This study provides in vivo and in vitro evidence for PGRMC1's function in female reproduction.