Ng Justin H J, Tachedjian Mary, Deakin Janine, Wynne James W, Cui Jie, Haring Volker, Broz Ivano, Chen Honglei, Belov Katherine, Wang Lin-Fa, Baker Michelle L
CSIRO Health and Biosecurity Business Unit, Australian Animal Health Laboratory, Geelong, VIC 3220, Australia.
Faculty of Veterinary Science, University of Sydney, NSW 2006, Australia.
Sci Rep. 2016 Feb 15;6:21256. doi: 10.1038/srep21256.
Bats are natural hosts to numerous viruses and have ancient origins, having diverged from other eutherian mammals early in evolution. These characteristics place them in an important position to provide insights into the evolution of the mammalian immune system and antiviral immunity. We describe the first detailed partial map of a bat (Pteropus alecto) MHC-I region with comparative analysis of the MHC-I region and genes. The bat MHC-I region is highly condensed, yet relatively conserved in organisation, and is unusual in that MHC-I genes are present within only one of the three highly conserved class I duplication blocks. We hypothesise that MHC-I genes first originated in the β duplication block, and subsequently duplicated in a step-wise manner across the MHC-I region during mammalian evolution. Furthermore, bat MHC-I genes contain unique insertions within their peptide-binding grooves potentially affecting the peptide repertoire presented to T cells, which may have implications for the ability of bats to control infection without overt disease.
蝙蝠是众多病毒的天然宿主，其起源古老，在进化早期就与其他真兽类哺乳动物分道扬镳。这些特征使它们在深入了解哺乳动物免疫系统和抗病毒免疫的进化方面具有重要地位。我们描述了蝙蝠（黑首狐蝠）主要组织相容性复合体I类（MHC-I）区域的首张详细局部图谱，并对MHC-I区域和基因进行了比较分析。蝙蝠的MHC-I区域高度浓缩，但在组织上相对保守，其不同寻常之处在于MHC-I基因仅存在于三个高度保守的I类重复块中的一个内。我们推测MHC-I基因最初起源于β重复块，随后在哺乳动物进化过程中逐步在MHC-I区域内复制。此外，蝙蝠的MHC-I基因在其肽结合槽内含有独特的插入序列，这可能会影响呈递给T细胞的肽库，这可能对蝙蝠在无明显疾病的情况下控制感染的能力产生影响。
