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

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.

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.

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.

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.