Direct in utero engineering of mouse models

Introduction

Mouse models are a gold standard for life sciences research, spanning developmental biology, cancer studies, and pre-clinical testing, but they also have important limitations. Mouse colony maintenance is expensive, and the large colonies needed are ethically problematic.

Limitations of Mouse Models

Approaches aiming for cell-type specific manipulations can be confounded by:

• Leaky promoters
• Off-target/unknown promoter expression
• Endogenous Cre sites
• Cre toxicity

Finally, mouse strains generated in different inbred genetic backgrounds yield confounding results when interbred, or necessitate extensive back-crossing, which again leads to large usage of mice. An alternative strategy to generate mouse models, circumventing these issues, is direly needed.

NEPTUNE Technology

To solve this problem for the mouse nervous system, we previously developed neural plate targeting with in utero nano-injection (NEPTUNE). NEPTUNE targets 95% of cells in the brain, can recapitulate established mouse models, and can be used flexibly for cell-type specific manipulations.

LIMITLESS Project

In LIMITLESS, my lab will leverage our expertise in ultra-high titer viral production, developmental biology, and technology development to go beyond the state of the art and develop a technology for whole-embryo editing in utero. We will combine this technology with next generation single cell lineage tracing to resolve the “family tree” of all cell types in developing embryos, providing both fundamental new knowledge and information that is leverageable for further development of the technique.

Conclusion

In sum, my lab will develop a much-needed technology for whole embryo genetic manipulation, opening the door to limitless new types of experiments. Direct in utero whole-embryo gene editing would accelerate life sciences research, reduce the financial and ethical costs of animal work, and enable experiments currently beyond reach with existing technology.