RNA-binding proteins in human oogenesis: Balancing differentiation and self-renewal in the female fetal germline

- RNA-binding proteins (RBPs) are key regulators of gene expression during oogenesis.
- RBPs LIN28, DAZL, BOLL and FMRP display stage-specific expression in fetal oocytes.
- LIN28 and DAZL may regulate self-renewal and progression into meiosis respectively.
- BOLL and FMRP may be involved in the later stages of prophase I and oocyte growth.
- RBPs may have critical roles in establishing the ovarian reserve during fetal life.

Primordial germ cells undergo three significant processes on their path to becoming primary oocytes: the initiation of meiosis, the formation and breakdown of germ cell nests, and the assembly of single oocytes into primordial follicles. However at the onset of meiosis, the germ cell becomes transcriptionally silenced. Consequently translational control of pre-stored mRNAs plays a central role in coordinating gene expression throughout the remainder of oogenesis; RNA binding proteins are key to this regulation. In this review we examine the role of exemplars of such proteins, namely LIN28, DAZL, BOLL and FMRP, and highlight how their roles during germ cell development are critical to oogenesis and the establishment of the primordial follicle pool.