Epigenetic potential affects immune gene expression in house sparrows
Epigenetic potential affects immune gene expression in house sparrows
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DOI：
10.1242/jeb.238451
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发表时间：
2021-03
影响因子：
2.8
通讯作者：
H. Hanson;C. Zimmer;Bilal Koussayer;A. Schrey;J. Maddox;Lynn B. Martin
中科院分区：
文献类型：
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作者：
H. Hanson;C. Zimmer;Bilal Koussayer;A. Schrey;J. Maddox;Lynn B. Martin
摘要：表观遗传机制可能在调节表型可塑性方面发挥核心作用，特别是在范围扩张期间，当种群面临一系列新的环境条件时。个体的表观遗传潜力（EP；基因表达表观遗传修饰的能力）可能有所不同，这可能会影响他们殖民新地区的能力。 EP 的一种形式，即 CpG 位点的数量，在微生物监视基因 Toll 样受体 4 (TLR4) 的启动子区域，引入的家麻雀 (Passer Domesticus) 中的 CpG 位点数量高于本地鸟类，这可能使入侵的鸟类能够微调其对不熟悉的寄生虫的免疫反应。在这里，我们比较了不同 EP 的麻雀全血、肝脏和脾脏中的 TLR4 基因表达，首先用脂多糖 (LPS) 刺激一些鸟类，通过模拟自然感染来增加基因表达。我们预计高 EP 将预测用 LPS 处理的鸟类血液中 TLR4 表达的高诱导性和可逆性，但我们没有对器官进行定向预测，因为我们无法重复对这些组织进行采样。我们发现 EP 可预测所有组织中的 TLR4 表达。无论是否接受 LPS 治疗，具有高 EP 的鸟类比具有低 EP 的个体在血液中表达更多的 TLR4。只有具有高 EP 的女性才表现出基因表达的可逆性。此外，EP 的效果因性别和组织而异。总之，这些数据支持 EP 作为 TLR4 表达的调节因子之一。重点文章：微生物监视基因 (TLR4) 启动子中的 CpG 位点数量以组织和性别特异性方式预测家麻雀的基因表达。
ABSTRACT Epigenetic mechanisms may play a central role in mediating phenotypic plasticity, especially during range expansions, when populations face a suite of novel environmental conditions. Individuals may differ in their epigenetic potential (EP; their capacity for epigenetic modifications of gene expression), which may affect their ability to colonize new areas. One form of EP, the number of CpG sites, is higher in introduced house sparrows (Passer domesticus) than in native birds in the promoter region of a microbial surveillance gene, Toll-like Receptor 4 (TLR4), which may allow invading birds to fine-tune their immune responses to unfamiliar parasites. Here, we compared TLR4 gene expression from whole blood, liver and spleen in house sparrows with different EP, first challenging some birds with lipopolysaccharide (LPS), to increase gene expression by simulating a natural infection. We expected that high EP would predict high inducibility and reversibility of TLR4 expression in the blood of birds treated with LPS, but we did not make directional predictions regarding organs, as we could not repeatedly sample these tissues. We found that EP was predictive of TLR4 expression in all tissues. Birds with high EP expressed more TLR4 in the blood than individuals with low EP, regardless of treatment with LPS. Only females with high EP exhibited reversibility in gene expression. Further, the effect of EP varied between sexes and among tissues. Together, these data support EP as one regulator of TLR4 expression. Highlighted Article: The number of CpG sites in the promoter of a microbial surveillance gene (TLR4) predicted gene expression in house sparrows in a tissue- and sex-specific manner.