Estrogen Receptor Gene 1 (ESR1) Mediates Lipid Metabolism in Goose Hierarchical Granulosa Cells Rather than in Pre-Hierarchical Granulosa Cells

SIMPLE SUMMARY: Our study successfully cloned and obtained an 1866 bp segment of the full-length coding sequence (CDS) region of the estrogen receptor gene 1 (ESR1) in Sichuan white geese. We compared the involvement of ESR1 in lipid metabolism between pre-hierarchical granulosa cells and hierarchical granulosa cells in geese. Our findings indicate that ESR1 plays a more significant role in the lipid metabolism of hierarchical granulosa cells. When ESR1 is overexpressed in hierarchical granulosa cells, it leads to a reduction in lipid droplet deposition, cholesterol, and triglycerides, primarily regulated by APOB and PPARα, which control lipoprotein synthesis. Conversely, interfering with ESR1 in hierarchical granulosa cells results in increased lipid droplet deposition, cholesterol, and triglycerides. This increase is jointly mediated by ACCα, DGAT1, and SCD, which regulate fatty acid synthesis, as well as CPT1 and ATGL, which are involved in fatty acid degradation. ABSTRACT: (1) Background: The role of estrogen receptor gene 1 (ESR1) in female reproduction and lipid metabolism has been extensively investigated. However, its contribution to lipid metabolism during the development of poultry follicles remains unclear. (2) Methods: This study aimed to explore the function of ESR1 via overexpressing (ESR1(ov)) and interfering (ESR1(si)) with its expression in pre-hierarchical granulosa cells (phGCs) and hierarchical granulosa cells (poGCs). (3) Results: We successfully cloned and obtained an 1866 bp segment of the full-length CDS region of the Sichuan white goose ESR1 gene. In phGCs of the ESR1(ov) and ESR1(si) groups, there were no significant changes compared to the control group. However, in poGCs, the ESR1(ov) group exhibited decreased lipid deposition, triglycerides, and cholesterol compared to the control group, while the ESR1(si) group showed increased lipid deposition, triglycerides, and cholesterol. The expression of APOB and PPARα was significantly reduced in the ESR1(ov) group compared to the ESR1(ov)-NC group. Moreover, significant changes in the expression of ACCα, DGAT1, SCD, CPT1, and ATGL were observed between the ESR1(si) and ESR1(si)-NC group. (4) Conclusions: These findings shed light on the function and molecular mechanism of ESR1 in lipid metabolism in goose poGCs, providing a better understanding of the physiological process of goose follicular development.