Advances in interspecies chimerism in animals

In the case of various life-threatening diseases like end-stage organ failure, whole-organ transplantation is typically the central therapeutic option. However, the global shortage of transplantable human organs poses a major clinical challenge. Although animal organs that are anatomically and physiologically similar to human organs have been explored as alternatives, interspecies incompatibility remains a significant barrier. Interspecies chimerism has emerged as a promising strategy to address this issue. By harnessing the self-organizing capacity of embryos in vivo, this approach enables the generation of complex organ structures and circumvents the limitations of in vitro differentiation. This review summarizes recent advances in interspecies chimerism research, focusing on donor cell types, mechanisms of cell competition, and current technical and ethical challenges. It also discusses the future potential of this technology for organ generation and transplantation, providing a theoretical foundation for research in developmental biology and regenerative medicine.