Work

17β-estradiol mediates sex-biased progesterone receptor expression via estrogen receptor α in chicken pituitary

Year: 2025

Type: article

Abstract: ABSTRACT Sex-biased in gene expression is a pervasive biological phenomenon in animals and plays critical roles in sex-dependent physiological activities. While previous studies have identified numerous genes displaying sex-biased expression at pre- or post-sexual maturity, the regulatory mechanisms driving such differential expression remain poorly understood. Our earlier work showed that progesterone receptor ( PGR ) expression in the chicken pituitary exhibits sex bias. Herein, we aimed to identify key gonadal steroids and their regulatory mechanisms mediating female-enriched PGR expression in the chicken pituitary. Our results showed that: (1) Pituitary PGR expression in sexually mature chickens was confirmed to be sex-biased; (2) Both in vitro assays and subcutaneous injections demonstrated that 17β-estradiol (E 2 ) potently stimulated PGR expression in the chicken pituitary in a time- and dose-dependent manner, whereas progesterone and dihydrotestosterone showed no such effect; (3) E 2 -induced PGR transcription relies on estrogen receptor α (ERα) rather than ERβ or G protein-coupled estrogen receptor; (4) Single-cell RNA-seq analysis revealed 26.3% co-expression of ESR1 (the ERα-encoding gene) and PGR in chicken gonadotrophs; (5) E 2 -elevated PGR expression may involve both membrane-anchored ERα (mERα)-triggered rapid non-genomic pathways and ERα-associated long-lasting genomic actions; (6) mERα-mediated regulation of pituitary PGR expression in chickens might be linked to PLC-dependent dual messenger systems (IP3/Ca 2+ and DAG/PKC), the MEK/ERK cascade, and L-type voltage-gated Ca 2+ channels. These findings provide novel insights into the estrogen-dependent regulatory mechanisms of sex-biased PGR expression in the avian pituitary, advancing our understanding of estrogen-mediated modulation of the reproductive axis in birds.

Source: Poultry Science

DOI: 10.1016/j.psj.2025.106210