Major histocompatibility complex (MHC) polymorphisms are associated with animal and human diseases. However, only a few studies have reported an association between MHC polymorphisms and mycoplasma ovipneumonia (MO). In the present study, three resistance/susceptibility genotypes associated with MO were identified by polymerase chain reaction-restriction fragment length polymorphism genotyping, assessing the clinical and pathological features, and examining the immune factors. The current results showed that MvaI bb and HaeIII ee were dominant genotypes in the susceptible Hu population, while MO-resistant populations, Dorper and D × H hybrids, were dominated by the MvaI cc and HaeIII dd genotypes, suggesting that MvaI cc and HaeIII dd genotypes might be associated with the trait of MO resistance. Further, the clinical symptoms and pathological morphology in the susceptibility group infected with MO were more severe than those in the resistant groups infected similarly. The data on the changes in the immune factor responses were utilized to deduce the molecular mechanism underlying the MO resistance/susceptibility. The results showed that the susceptible genotypes promote the inflammatory responses by inducing a high expression of TNFα, IFNγ, IL-4, IL-6, and IL-1β, while the resistant genotypes inhibit the inflammatory response by increasing the expression of IL-2 and IL-10 significantly. This finding would provide the theoretical guidance for propagating sheep breeds that are highly resistant to MO.

中文翻译：

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MHC-DRB1外显子2多态性及其与绵羊卵支原体肺炎抗性或易感基因型的关系

主要组织相容性复合体 (MHC) 多态性与动物和人类疾病有关。然而，只有少数研究报告了 MHC 多态性与卵支原体肺炎 (MO) 之间的关联。在本研究中，通过聚合酶链反应-限制性片段长度多态性基因分型、评估临床和病理特征以及检查免疫因素，鉴定了与 MO 相关的三种耐药/易感基因型。目前的结果表明，MvaI bb 和 HaeIII ee 是易感 Hu 群体中的优势基因型，而 MO 抗性群体 Dorper 和 D×H 杂种则以 MvaI cc 和 HaeIII dd 基因型为主，表明 MvaI cc 和 HaeIII dd基因型可能与 MO 抗性特征有关。更多，MO感染易感组的临床症状和病理形态较相似感染的耐药组更严重。利用免疫因子反应变化的数据来推断 MO 抗性/易感性的分子机制。结果表明，易感基因型通过诱导TNFα、IFNγ、IL-4、IL-6和IL-1β的高表达来促进炎症反应，而耐药基因型通过增加IL-2的表达来抑制炎症反应。和 IL-10 显着。这一发现将为繁殖对 MO 具有高度抗性的绵羊品种提供理论指导。利用免疫因子反应变化的数据来推断 MO 抗性/易感性的分子机制。结果表明，易感基因型通过诱导TNFα、IFNγ、IL-4、IL-6和IL-1β的高表达来促进炎症反应，而耐药基因型通过增加IL-2的表达来抑制炎症反应。和 IL-10 显着。这一发现将为繁殖对 MO 具有高度抗性的绵羊品种提供理论指导。利用免疫因子反应变化的数据来推断 MO 抗性/易感性的分子机制。结果表明，易感基因型通过诱导TNFα、IFNγ、IL-4、IL-6和IL-1β的高表达来促进炎症反应，而耐药基因型通过增加IL-2的表达来抑制炎症反应。和 IL-10 显着。这一发现将为繁殖对 MO 具有高度抗性的绵羊品种提供理论指导。而耐药基因型通过显着增加IL-2和IL-10的表达来抑制炎症反应。这一发现将为繁殖对 MO 具有高度抗性的绵羊品种提供理论指导。而耐药基因型通过显着增加IL-2和IL-10的表达来抑制炎症反应。这一发现将为繁殖对MO具有高度抗性的绵羊品种提供理论指导。