Multicellular state transitions and signaling rewiring during the proestrus-to-estrus switch in the porcine ovary

Background The porcine ovary undergoes rapid multicellular remodeling during the transition from proestrus to estrus, but the cell type–specific regulatory programs that drive this process remain incompletely defined. Here, we aimed to resolve stage-dependent cellular states and intercellular signaling events in the porcine ovary across proestrus and estrus at single-cell resolution. Results We generated a stage-resolved single-nucleus RNA sequencing atlas of porcine ovaries spanning proestrus and estrus. Integrative analyses of granulosa cell heterogeneity, metabolic pathway activity, and inferred metabolic flux highlighted ERBB4 and the glutamine transporter SLC1A5 as key regulatory factors associated with the proestrus-to-estrus transition. By combining cell type–specific differential expression profiling with intercellular communication network analysis across major ovarian somatic compartments, we further identified transforming growth factor beta (TGF-β) signaling as a central regulatory axis coordinating this developmental transition. Together, these data delineate coordinated transcriptional, metabolic, and microenvironmental remodeling programs during the proestrus-to-estrus switch. Conclusions This study provides a high-resolution cellular resource for the porcine ovary across proestrus and estrus and proposes ERBB4 , SLC1A5 , and TGF-β pathway components as candidate targets for modulating estrus-associated ovarian remodeling. These findings may support improved estrus detection, earlier recognition of reproductive disorders, and more precise reproductive management in swine production systems.