The low egg production of goose greatly limits the development of the industry. China possesses the most abundant goose breeds resources. In this study, genome resequencing data of swan goose (Anser cygnoides) and domesticated high and low laying goose breeds (Anser cygnoides domestiation) were used to identify key genes related to egg laying ability in geese and verify their functions. Selective sweep analyses revealed 416 genes that were specifically selected during the domestication process from swan geese to high laying geese. Furthermore, SNPs and Indels markers were used in GWAS analyses between high and low laying breed geese. The results showed that RTCB, BPIFC, SYN3, SYNE1, VIP, and ESR1 may be related to the differences in laying ability of geese. Notably, only ESR1 was identified simultaneously by GWAS and selective sweep analysis. The genotype of Indel_{chr3:54429172}, located downstream of ESR1, was confirmed to affect the expression of ESR1 in the ovarian stroma and showed significant correlation with body weight at first egg and laying frequency of geese. CCK-8, EdU, and flow cytometry confirmed that ESR1 can promote the apoptosis of goose pre-hierarchical follicles ganulosa cells (phGCs) and inhibit their proliferation. Combined with transcriptome data, it was found ESR1 involved in the function of goose phGCs may be related to MAPK and TGF-beta signaling pathways. Overall, our study used genomic information from different goose breeds to identify an indel located in the downstream of ESR1 associated with goose laying ability. The main pathways and biological processes of ESR1 involved in the regulation of goose laying ability were identified by cell biology and transcriptomics methods. These results are helpful to further understand the laying ability characteristics of goose and improve the egg production of geese.

Geese, descendants of migratory birds, have preserved the distinct reproductive and lipid metabolism traits of their wild ancestors. Therefore, compared to other poultry, geese have lower egg production ability and greater susceptibility to fatty liver. Recent research underscores the impact of lipid metabolism disorders on female reproductive health. In this context, we observed reproductive disorders (RD) and lipid metabolism anomalies in certain geese populations. This study systematically elucidated the differences between RD and normal geese at various levels, including genomics, transcriptomics, bile acid metabolomics, and microbiomics, revealing the crucial role of microorganisms. Our study provides a thorough examination of the ovarian anatomical, histological, and transcriptomic profiles between normal and RD geese. Genomic analyses pinpoint mutations in genes associated with bile acid metabolism, highlighting their potential role in RD pathogenesis. The genomic discoveries are substantiated by precise bile acid assays and ileum transcriptome analyses, which expose a significant disruption in bile acid absorption, activation of FXR, and an increase in serum chenodeoxycholic acid (CDCA) concentrations within RD geese. Notably, 16S rRNA sequencing uncovers significantly greater beta diversity in the ileum microbiota of RD geese than in the normal group. Both Wilcoxon rank sum test and LEfSe analyses highlighted a marked increase in Romboutsia abundance in RD geese. Experimental cultivation of microbiota with CDCA supplementation confirms the impact of CDCA on Romboutsia lituseburensis proliferation. Gavage experiments with R. lituseburensis elucidate its involvement in primary follicle reduction via immune-mediated pathways. Collectively, our multifaceted analysis unravels the intricate involvement of Romboutsia in goose RD, offering insights from genetic, physiological, and microbial dimensions. Our findings not only deepen understanding of the etiology of RD in geese but also suggest potential avenues for therapeutic interventions targeting bile acid metabolism and modulation of specific microbiota components.