Recombination and purifying and balancing selection determine the evolution of major antigenic protein 1 (map 1) family genes in Ehrlichia ruminantium.
Recombination and purifying and balancing selection determine the evolution of major antigenic protein 1 (map 1) family genes in Ehrlichia ruminantium.
复制标题
重组、纯化和平衡选择决定了反刍埃里希体主要抗原蛋白 1（图谱 1）家族基因的进化。
DOI：
10.1016/j.gene.2018.10.028
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发表时间：
2019
期刊：
影响因子：
3.5
通讯作者：
Nakao R.
中科院分区：
文献类型：
--
作者：
Salim B;Amin M;Igarashi M;Ito K;Jongejan F;Katakura K;Sugimoto C;Nakao R.
反刍动物心水病是由蜱传反刍埃里希体引起的一种经济上重要的疾病。这种疾病存在于整个撒哈拉以南非洲地区以及加勒比地区的几个岛屿上，在那里它构成了传播到美国大陆的风险。受感染动物的主要免疫应答是针对E.反刍动物由多态性多基因家族编码。在这里，我们研究了全长序列的主要抗原蛋白1（map 1）家族基因在multipleE。ruminantiumisolates从不同的非洲国家和加勒比地区，收集在不同的时间点，以推断重组断点和自然选择的可能作用。特别是在map 1和map 1 -2中发现了高水平的重组。来自不同地理国家的这些样本中存在强烈的负净化选择和平衡选择以维持遗传变异的证据表明宿主-病原体共同进化。宿主和病原体之间的这种共同进化通过保持遗传多样性来平衡选择，这可以用长期病原体压力的人口统计历史来解释。这意味着适应性的作用和分子进化的力量支撑E。反刍动物map 1多基因家族抗原性。
Heartwater is an economically important disease of ruminants caused by the tick-borne bacterium Ehrlichia ruminantium. The disease is present throughout sub-Saharan Africa as well as on several islands in the Caribbean, where it poses a risk of spreading onto the American mainland. The dominant immune response of infected animals is directed against the variable outer membrane proteins ofE. ruminantiumencoded by a polymorphic multigene family. Here, we examined the full-length sequence of the major antigenic protein 1 (map1) family genes in multipleE. ruminantiumisolates from different African countries and the Caribbean, collected at different time points to infer the possible role of recombination breakpoint and natural selection. A high level of recombination was found particularly inmap1andmap1–2. Evidence of strong negative purifying selection inmap1and balancing selection to maintain genetic variation across these samples from geographically distinct countries suggests host–pathogen co-evolution. This co-evolution between the host and pathogen results in balancing selection by maintaining genetic diversity that could be explained by the demographic history of long-term pathogen pressure. This signifies the adaptive role and the molecular evolutionary forces underpinningE. ruminantium map1multigene family antigenicity.