Mosaic analysis of gene function in postnatal mouse brain development by using virus-based Cre recombination

Area of Science:

• Neuroscience
• Developmental Biology
• Genetics

Background:

• Postnatal brain development is critical for neural circuit maturation and refinement.
• Gene misregulation during this stage is linked to neurological and psychiatric disorders.
• Studying gene function in the postnatal brain is challenging due to early lethality and developmental requirements.

Purpose of the Study:

• To develop a rapid and systematic method for studying gene function in the postnatal mouse brain.
• To overcome limitations of traditional conditional knockout mouse models.
• To enable large-scale genetic analysis of postnatal neural development.

Main Methods:

• Utilized recombinant adeno-associated viruses (rAAVs) encoding Cre recombinase injected into the neonatal brain.
• Achieved mosaic gene inactivation and sparse neuronal labeling by controlling viral titer and coexpressing fluorescent markers.
• Bypassed gene requirements in early development for postnatal analysis.

Main Results:

• Demonstrated a complementary approach to study floxed alleles in postnatal brain development.
• Enabled investigation of cell-autonomous gene functions in axonal/dendritic growth, branching, tiling, and synapse formation.
• Successfully applied to study critical processes in postnatal neural circuit development.

Conclusions:

• Virally-expressed Cre provides a powerful and efficient strategy for studying gene function in the postnatal brain.
• This method facilitates research into genetic pathways influencing neural circuit development and function.
• The technique is adaptable to other viruses and genetic manipulations, and combinable with advanced imaging and electrophysiology.