Targeted gene transfer into developmentally defined cell populations of the primate brain

Area of Science:

• Neuroscience
• Genetics
• Developmental Biology

Background:

• Primate brain research is limited by a lack of effective transgenic models and tools.
• Existing methods for genetic manipulation in primates are often invasive or inefficient.

Purpose of the Study:

• To develop a minimally invasive method for widespread transgene delivery to the fetal primate cerebral cortex.
• To establish a versatile tool for genetic manipulation and cell labeling in the developing primate brain.

Main Methods:

• Ultrasound-guided fetal intracerebroventricular viral injections (FIVIs) using adeno-associated viruses (AAVs).
• Optimization of gestational timing, AAV serotype, and regulatory elements for targeted gene expression in marmosets.
• Demonstration of prenatal CRISPR-based gene editing and pathway labeling in rats.

Main Results:

• FIVIs enable efficient, long-lasting transgene expression in the fetal primate cortex.
• Selective targeting of specific cell populations, including layer-restricted labeling and Cre-dependent intersectional access, was achieved.
• Proof-of-concept for prenatal gene editing and labeling of peripheral pathways in rats.

Conclusions:

• FIVIs provide an efficient and targeted method for gene transfer into the fetal primate brain.
• This technique expands experimental possibilities for studying primate brain development and function.
• The method mimics desirable features of germline transgenic models for neuroscience research.