Macrophages and Their Organ Locations Shape Each Other in Development and Homeostasis - A Perspective.

Across the animal kingdom, macrophages are known for their functions in innate immunity, but they also play key roles in development and homeostasis. Recent insights from single cell profiling and other approaches in the invertebrate model organism reveal substantial diversity among macrophages (plasmatocytes). Together with vertebrate studies that show genuine expression signatures of macrophages based on their organ microenvironments, it is expected that macrophage functional diversity is shaped by their anatomical locations and systemic conditions. evidence for diverse macrophage functions has already been well established by genetics: macrophages play key roles in various aspects of development and organogenesis, including embryogenesis and development of the nervous, digestive, and reproductive systems. Macrophages further maintain homeostasis in various organ systems and promote regeneration following organ damage and injury. The interdependence and interplay of tissues and their local macrophage populations in have implications for understanding principles of organ development and homeostasis in a wide range of species.