Abstract

Simple SummaryLow egg production and intense broodiness limit the breeding efficiency and economic value of indigenous poultry breeds. The Wuding chicken, a local breed from Yunnan Province, is valued for its superior meat quality but exhibits suboptimal reproductive performance. Elucidating the regulatory mechanisms underlying reproductive performance in indigenous chickens is therefore essential for sustainable poultry development. Estrogen Receptor 2 (ESR2) is involved in ovarian development and ovulation, yet its specific function in granulosa cells (GCs) remains unclear. This study investigated how ESR2 influences follicular development and GC function in Wuding chickens. These findings indicate that ESR2 regulates GC function through a synergistic interplay between genomic and non-genomic actions. As a transcription factor, ESR2 transcriptionally upregulates key components of the PI3K/AKT/mTOR signaling pathway, thereby enhancing the expression of genes associated with GC proliferation and steroidogenesis. Meanwhile, its cytoplasmic localization suggests that ESR2 is involved in rapid signaling events and non-genomic regulatory processes. Together with its nuclear localization, these observations indicate an integrated regulatory mode of genomic and non-genomic actions in GCs of Wuding chicken. These results provide new insights into reproductive regulation in indigenous chicken breeds and offer theoretical support for improving breeding efficiency and advancing the development of characteristic poultry industries.The Wuding chicken, a renowned indigenous breed in Yunnan Province, is prized for its superior meat quality; however, its economic potential is limited by pronounced broodiness and suboptimal egg production. Central to alleviating these constraints is the precise regulation of ovarian granulosa cell (GC) proliferation and steroidogenic processes that d