Female cortical cellular mosaicism underlies shared MeCP2 and PCB impacted gene pathways

Area of Science:

• Neuroscience
• Genetics
• Environmental Health

Background:

• Rett syndrome (RTT) is a neurodevelopmental disorder linked to MECP2 mutations.
• Environmental factors, like PCBs, may influence RTT severity and progression.
• Understanding gene-environment interactions is crucial for neurodevelopmental research.

Purpose of the Study:

• To investigate shared molecular mechanisms between MECP2 mutations and PCB exposure.
• To explore how PCBs affect transcriptional changes in a mouse model of RTT.
• To determine the impact of PCBs on non-cell-autonomous gene expression in the context of MECP2 mutations.

Main Methods:

• Exposure of wild-type and Mecp2e1^-/+ female mice to a PCB mixture.
• Single-nucleus 5' RNA sequencing of cortical tissue.
• Bioinformatic analysis to identify overlapping dysregulated genes and pathways.

Main Results:

• Significant overlap in dysregulated genes and 71 shared pathways between PCB exposure and MECP2 mutation.
• PCBs modulated the transcriptional effects of MECP2 mutations in wild-type-expressing neurons.
• Evidence of co-mitigation of transcriptional impacts by PCBs and MECP2 mutation.

Conclusions:

• PCBs and MECP2 mutations interact, influencing shared homeostatic gene networks.
• These interactions have implications for understanding gene-environment interplay in neurodevelopment.
• Findings suggest environmental factors can modify the molecular pathology of RTT.