Sabino-Pinto Joana, Maan Martine E
Groningen Institute for Evolutionary Life Sciences, University of Groningen, Groningen, Netherlands.
J Mol Evol. 2025 Feb;93(1):38-61. doi: 10.1007/s00239-024-10223-7. Epub 2025 Jan 7.
The major histocompatibility complex (MHC) is a cluster of functionally related genes encoding proteins which, among other functions, mediate immune system activation. While the MHC of many vertebrates has been extensively studied, less is known about the amphibian MHC. This represents an important knowledge gap because amphibians mark the evolutionary transition from an aquatic to a terrestrial lifestyle and often maintain a biphasic lifestyle. Hence, they tend to be exposed to both aquatic and terrestrial pathogen communities, providing opportunities to gain fundamental insights into how the immune system responds to different environmental challenges. Moreover, amphibians are globally threatened by invasive pathogens and the MHC may play a role in combating population decline. In this review, we summarize the current state of knowledge regarding the amphibian MHC and identify the major differences with other vertebrates. We also review how the number of MHC gene copies varies across amphibian groups and how MHC-based variation relates to amphibian ontogeny, behaviour, disease, and phylogeography. We conclude by identifying knowledge gaps and proposing priorities for future research.
主要组织相容性复合体（MHC）是一组功能相关的基因簇，其编码的蛋白质除了其他功能外，还介导免疫系统的激活。虽然许多脊椎动物的MHC已得到广泛研究，但关于两栖动物MHC的了解却较少。这代表了一个重要的知识空白，因为两栖动物标志着从水生到陆生生活方式的进化转变，并且通常保持双相生活方式。因此，它们往往会接触到水生和陆生病原体群落，这为深入了解免疫系统如何应对不同环境挑战提供了机会。此外，两栖动物受到入侵病原体的全球威胁，而MHC可能在对抗种群数量下降方面发挥作用。在这篇综述中，我们总结了关于两栖动物MHC的当前知识状态，并确定了与其他脊椎动物的主要差异。我们还回顾了两栖动物群体中MHC基因拷贝数如何变化，以及基于MHC的变异如何与两栖动物的个体发育、行为、疾病和系统地理学相关。我们通过识别知识空白并提出未来研究的重点来得出结论。
