Ovarian Follicular Development in Porcine Species

Ovarian follicular development in pigs encompasses the growth and maturation of ovarian follicles from a quiescent primordial pool through preantral and antral stages to the preovulatory phase, culminating in ovulation and subsequent corpus luteum formation. Follicle recruitment is governed by follicle‐stimulating hormone (FSH), with later stages becoming increasingly dependent on luteinising hormone (LH). Within each follicle, granulosa and theca cells interact via steroidogenic pathways and growth factors to regulate oocyte competence and endocrine secretions, notably oestradiol and progesterone. Continuous recruitment and selection of follicles ensure a dynamic ovarian reserve, while atresia eliminates non-selected units. Coordinated steroidogenesis, angiogenesis and extracellular matrix remodelling underpin the transition from preovulatory follicle to functional corpus luteum, with implications for fertility management and swine production efficiency.

Research from Nature Portfolio

Recent studies have revealed that atretic preovulatory follicles may serve as precursors of lutein cysts, characterised by a shift from an oestrogenic to a progestational steroid milieu and altered expression of key enzymes (CYP17A1, HSD17B1, CYP19A1, HSD3B1) and inflammatory mediators such as TNFα. Loss of progesterone receptor abundance appears to disrupt the ovulatory cascade, facilitating premature luteinisation of follicular walls. Complementary work has compared exogenous human chorionic gonadotropin (hCG) and gonadotropin-releasing hormone agonist triggers in prepubertal versus mature gilts, demonstrating that hCG induces a progestational and androgenic profile, whereas endogenous LH promotes an oestrogenic and development-focused environment. These triggers differentially modulate receptor abundance (FSHR, LHCGR) and proteins involved in steroidogenesis (STAR, HSD3B1, CYP11A1), prostaglandin synthesis, extracellular matrix remodelling and cell survival.

Ovarian Follicular Development in Porcine Species publication trend

The graph below shows the total number of articles in ovarian follicular development in porcine species across all publications each year (not limited to Nature Index journals).

Technical terms

Folliculogenesis: The process by which ovarian follicles develop from primordial stages to preovulatory maturity.

Atresia: Programmed degeneration of non-selected ovarian follicles.

Granulosa cell: Somatic cell lining the follicle that supports oocyte maturation and steroidogenesis.

Theca cell: Interstitial follicular cell that collaborates with granulosa cells to produce androgens.

Luteinization: Transformation of follicular cells into luteal cells following ovulation.

Antral follicle: Follicle containing a fluid‐filled cavity (antrum) visible under microscopy.

Gonadotropins: Pituitary hormones (FSH, LH) that regulate follicle growth and ovulation.

Corpus luteum: Transient endocrine structure formed from luteinized follicular cells, producing progesterone.

References

1. Follicle development in pigs: State of the art. Molecular Reproduction and Development (2022).
2. Atretic preovulatory follicles could be precursors of ovarian lutein cysts in the pig. Scientific Reports (2023).
3. Endocrine and molecular milieus of ovarian follicles are diversely affected by human chorionic gonadotropin and gonadotropin-releasing hormone in prepubertal and mature gilts. Scientific Reports (2021).
4. Attainment of Sexual Maturity and Gonadotropin Priming in Gilts Determine Follicular Development, Endocrine Milieu and Response to Ovulatory Triggers. International Journal of Molecular Sciences (2022).
5. Proteomic Analysis of Porcine Pre-ovulatory Follicle Differentiation Into Corpus Luteum. Frontiers in Endocrinology (2019).