Sex-dimorphic reprogramming of fetal mouse brain development by maternal estradiol excess.

BACKGROUND: Gestational environmental perturbations can induce sex-specific developmental programming, increasing offspring susceptibility to chronic diseases. While prenatal high estradiol (HE) exposure has been associated with male-biased neurodevelopmental disorders, the underlying mechanisms remain poorly understood. METHODS: Using spatial transcriptomics in a murine HE exposure model, we systematically characterized sex-divergent molecular and cellular responses in fetal brains. Through cell type identification, spatial mapping, ligand-receptor interaction analysis, and transcription factor activity assessment, we examined gene expression profile, intra-regional signaling pathway, and regulon activity variations. Additionally, we performed immunofluorescence to characterize neural progenitor cell dynamics. RESULTS: Our analysis revealed that maternal HE exposure differentially altered gene expression patterns between male and female fetal brain regions, with more pronounced effects on male-biased genes. Notably, HE-induced downregulation of male-biased genes was proportional to their baseline male-bias degree. We uncovered region-specific cellular responses to HE exposure and demonstrated sex-opposed alterations in intra-regional signaling pathway. Furthermore, we identified cell type- and brain region-restricted sex differences in regulon activity variations. Histological validation confirmed that maternal HE exposure specifically disrupts the proliferation-differentiation balance of neural progenitor cells in the male cerebral cortex. CONCLUSIONS: These findings provide mechanistic insights into sex-dimorphic developmental reprogramming of fetal brain by maternal estradiol excess. They establish a framework for developing targeted interventions against gestational endocrine disruption-induced neurodevelopmental disorders.