# A dual-reporter mouse for therapeutic discovery in Angelman syndrome

## TL;DR

A new mouse model with dual reporters helps speed up the development of therapies for Angelman syndrome by enabling detailed and scalable analysis of UBE3A.

## Contribution

The Ube3a-INSG dual-reporter mouse combines two complementary readouts for scalable and high-resolution preclinical studies.

## Key findings

- Sun1-sfGFP allows single-cell fluorescence analysis and whole-brain imaging.
- Nanoluciferase enables high-throughput assays and noninvasive in vivo imaging.
- The model supports sorting neurons with unsilenced paternal Ube3a.

## Abstract

Angelman syndrome is a neurodevelopmental disorder caused by loss of the maternal UBE3A allele, the sole source of UBE3A in mature neurons owing to epigenetic silencing of the paternal allele. Although emerging therapies are being developed to restore UBE3A expression by activating the dormant paternal UBE3A allele, existing mouse models for such preclinical studies have limited throughput and utility, creating bottlenecks for both in vitro therapeutic screening and in vivo characterization. To address this, we developed the Ube3a-INSG dual-reporter knockin mouse, in which an IRES-Nanoluciferase-T2A-Sun1-sfGFP (INSG) cassette was inserted downstream of the endogenous Ube3a stop codon. The INSG model preserves UBE3A protein levels and function while enabling 2 complementary allele-specific readouts: Sun1-sfGFP and Nanoluciferase. We show that Sun1-sfGFP, a nuclear envelope–localized reporter, enables single-cell fluorescence analysis, whole-brain light-sheet imaging, and nuclear quantification by flow cytometry. Further, Nanoluciferase supports high-throughput luminescence assays for sensitive pharmacological profiling in cultured neurons and noninvasive in vivo bioluminescence imaging for pharmacodynamic assessment. By combining scalable screening, cellular analysis, and real-time in vivo monitoring in a single model, the Ube3a-INSG dual-reporter mouse provides a powerful platform to accelerate therapeutic development centered on UBE3A.

Multimodal dual-reporter mouse accelerates Angelman syndrome therapeutic development through scalable cell-based screening, high-resolution whole-brain mapping, non-invasive live imaging, and sorting neurons with unsilenced paternal Ube3a.