A blastocyst complementation approach to study forebrain development, evolution and function

/ABSTRACT Interspecies blastocyst complementation (IBC) holds great potential to open new avenues for neuroscience, offering a unique perspective on brain development and evolution. This technique introduces donor pluripotent stem cells (PSCs) into host blastocysts lacking essential organ development genes, enabling the formation of interspecies chimeras. Such chimeras allow for the development of donor-cell-enriched organs in host organisms, a method previously applied to create various organs but not yet successful for brain tissue. Our preliminary studies have introduced a C-CRISPR-based blastocyst complementation method (CCBC), enabling the generation of rat forebrain tissue in mice for the first time. This allows us to study brain development and function from an evolutionary angle, potentially transforming brain research and providing a foundation for ethical considerations regarding the use of human PSCs in animal brains. Building on this, our proposal aims to dissect the xenogeneic barriers affecting brain development between mice and rats, explore non-cell autonomous mechanisms in rat-mouse forebrain chimeras, and attempt to create forebrain tissues from a wide rodent species, African pygmy mouse, in mice. Our objectives include: 1) Understanding Xenogeneic Barriers: Investigating the decline in rat cell contribution in chimeric mouse forebrains, potentially due to cell competition, proliferation differences, or cell adhesion incompatibility, and exploring strategies to overcome these barriers. 2) Exploring Non-Cell Autonomous Mechanisms: Examining how rat-mouse chimeras adapt brain size and developmental pace to the mouse host, using multi-omics analyses and interspecies mesenchymal blastocyst complementation to uncover the molecular and cellular basis of these effects. 3) Expanding to Wild Rodent Species: Venturing beyond common laboratory models to study the forebrains of wild rodents, such as the African pygmy mouse, to broaden our understanding of brain development. Our proposed study promises to illuminate fundamental aspects of brain organization, functionality, and evolutionary dynamics. Project Number: 1R01NS147445-01 | Fiscal Year: 2026 | NIH Institute/Center: National Institute of Neurological Disorders and Stroke (NINDS) | Principal Investigator: Jun Wu | Institution: UT SOUTHWESTERN MEDICAL CENTER, DALLAS, TX | Award Amount: $655,557 | Activity Code: R01 | Study Section: Neurogenesis and Cell Fate Study Section[NCF] View on NIH RePORTER: https://reporter.nih.gov/project-details/11318735