Research Progress on the Major Histocompatibility Complex in Herbivores: Structure, Genetics, and Disease Resistance

Abstract

Simple Summary Herbivores such as cattle, sheep, goats, horses, and donkeys are vital to farming and to many natural ecosystems, yet they are constantly challenged by infections caused by parasites, viruses, and bacteria. Whether an individual animal can fight off a particular infection depends heavily on a family of immune genes, called the major histocompatibility complex, that help the body recognize foreign invaders and trigger the right defensive response. These genes vary widely between individuals: some versions make an animal more resistant to a given disease, while others leave it more vulnerable. In this review, we bring together recent research on how these immune genes are organized, how they are passed from parents to offspring, how they have changed over evolutionary time, and how they shape an animal’s likelihood of becoming ill or responding well to vaccination. We also describe new laboratory tools that are making these complex genes easier to study. This knowledge can help farmers breed healthier, more disease-resistant livestock, help conservationists safeguard endangered species, and guide the design of more effective vaccines. Ultimately, the work supports more sustainable animal agriculture, better animal welfare, and the protection of wildlife.