Transcription factors in the maintenance and survival of primordial follicles

Abstract

Primordial follicles are formed prenatally in mammalian ovaries, and at birth they are fated to be activated to primary follicles, to be dormant, or to die. During the early stage of folliclulogenesis, the oocyte undergoes dynamic alterations in expression of numerous genes, which are regulated by transcription factors. Several germ-cell specific transcriptional regulators are critical for formation and maintenance of follicles. These transcriptional regulators include: Figla, Lhx8, Nobox, Sohlh1, and Sohlh2. A subset of these transcriptional regulators is mutated in women with ovarian insufficiency and infertility. Establishment of this oocyte pool is essential for fertility. This review focuses on these transcriptional regulators of female primordial follicles.

Keywords: Figla; Lhx8; Nobox; Primordial follicles; Sohlh1; Sohlh2; Transcription factors.

Figure 1

Regulatory networks of transcriptional regulators, SOHLH1, SOHLH2, NOBOX, LHX8 and FIGLA (Modified from Choi and Rajkovic [5]). Black line, direct regulation; Blue line, putative regulation; ZP, zona pellucida; GDF9, growth differentiation factor 9; POU5f1, POU class 5 homeobox 1; PAD6, peptidyl arginine deiminase type VI; OOG1, oogenesin 1; cMOS, moloney sarcoma oncogene; ZAR1, zygote arrest 1; OOSP1, oocyte secreted protein 1; NPM2, nucleoplasmin 2; DMRT1, doublesex and mab-3 related transcription factor 1; STRA8, stimulated by retinoic acid gene 8; CASP, caspase; BAX, BCL2-associated X protein; KITL, kit ligand; TDRD, tudor domain containing; OAS1, 2'-5' oligoadenylate synthetase 1; EXO1, exonuclease 1; NLRP, NLR family, pyrin domain containing; DPPA3, developmental pluripotency-associated 3; H1foo, H1 histone family; member O, oocyte-specific.