By: Sarah Boles, Carly Russell, Tia Zephir, and Gabby Scarcella (Stonehill College, BIO323: Evolution, Spring 2021)
Have you ever wondered how your immune system just knows and acts on a variety of diseases? Especially now during COVID-19, it seems our immune systems are really being put to the test. The actions of your immune system are due to the major histocompatibility complex (MHC). In a recent article in BMC Evolutionary Biology, researchers from the University of Geneva and the Biomedical Primate Research Center wanted to see if MHC genes are conserved and evolving similarly in Western chimpanzees (Pan troglodytes verus) and humans. The MHC region, referred to as Patr in chimpanzees and HLA in humans, is a family of genes that plays a key role in a population’s adaptive immunity. MHC diversity could affect a population’s survival because these genes code for proteins that help combat viral infections and protect the organism from harmful pathogens. MHC genes are classified as class I genes or class II genes, which differ in structure and function. The class I genes are named A, B, and C, and target viral invaders, whereas class II genes, such as DPB1, DQB1, DQA1, and DRB1, target parasitic and bacterial invaders. The objective of this study was to determine if the genetic diversity at different Patr genes is significantly reduced in present day Western chimpanzees due to a past bottleneck effect, which is defined as the sudden decrease of a population from natural causes. The researchers also compared human and chimpanzee genetic diversity to determine if MHC molecular evolution mechanisms were conserved between the two species.
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