Adaptation and Cryptic Pseudogenization in Penguin Toll-Like Receptors.
Adaptation and Cryptic Pseudogenization in Penguin Toll-Like Receptors.
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企鹅Toll样受体的适应性和隐蔽性假基因化。
DOI：
10.1093/molbev/msab354
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发表时间：
2022-01-07
影响因子：
10.7
通讯作者：
Smith AL
中科院分区：
文献类型：
--
作者：
Fiddaman SR;Vinkler M;Spiro SG;Levy H;Emerling CA;Boyd AC;Dimopoulos EA;Vianna JA;Cole TL;Pan H;Fang M;Zhang G;Hart T;Frantz LAF;Smith AL
企鹅（Sphenisciformes）是一种标志性的不会飞的潜水海鸟，分布在南半球的大纬度范围内。企鹅流行的广泛地区可能会促进病原体压力的变化，这反过来又会对企鹅免疫系统施加不同的选择压力。在病原体检测和响应的第一线，Toll样受体（TLR）提供了对宿主进化的洞察，面对微生物的挑战。TLR对保守的病原体相关分子模式作出反应，并且经常被发现处于正选择下，尽管保留了对定义的激动剂类别的特异性。我们对所有企鹅物种的TLR进行了比较免疫遗传学分析，发现适应性进化的证据主要限于细胞表面表达的TLR，在TLR1B，TLR4和TLR5的关键激动剂结合位点或附近有正向选择的证据。有趣的是，被真菌产物激活的TLR15似乎在Eudyptes spp.中被多次假基因化，但在群体水平上，全长形式作为罕见的单倍型存在。然而，体外分析显示，即使是全长形式的Eudyptes TLR15也是无功能的，这表明在Eudyptes谱系中，在其最终多次破坏之前，存在祖先的隐蔽假基因化。这种不寻常的假基因化事件可以提供对真菌病原体（如曲霉菌）的免疫适应的见解，曲霉菌是导致野生和圈养鸟类种群显著死亡的原因。
Penguins (Sphenisciformes) are an iconic order of flightless, diving seabirds distributed across a large latitudinal range in the Southern Hemisphere. The extensive area over which penguins are endemic is likely to have fostered variation in pathogen pressure, which in turn will have imposed differential selective pressures on the penguin immune system. At the front line of pathogen detection and response, the Toll-like receptors (TLRs) provide insight into host evolution in the face of microbial challenge. TLRs respond to conserved pathogen-associated molecular patterns and are frequently found to be under positive selection, despite retaining specificity for defined agonist classes. We undertook a comparative immunogenetics analysis of TLRs for all penguin species and found evidence of adaptive evolution that was largely restricted to the cell surface-expressed TLRs, with evidence of positive selection at, or near, key agonist-binding sites in TLR1B, TLR4, and TLR5. Intriguingly, TLR15, which is activated by fungal products, appeared to have been pseudogenized multiple times in the Eudyptes spp., but a full-length form was present as a rare haplotype at the population level. However, in vitro analysis revealed that even the full-length form of Eudyptes TLR15 was nonfunctional, indicating an ancestral cryptic pseudogenization prior to its eventual disruption multiple times in the Eudyptes lineage. This unusual pseudogenization event could provide an insight into immune adaptation to fungal pathogens such as Aspergillus, which is responsible for significant mortality in wild and captive bird populations.
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影响因子：
3.7
作者：
Dalton DL;Vermaak E;Roelofse M;Kotze A
通讯作者：
Kotze A
DOI：
10.1073/pnas.0502040102
发表时间：
2005-06-28
影响因子：
11.1
作者：
Andersen-Nissen, E;Smith, KD;Aderem, A
通讯作者：
Aderem, A
影响因子：
10.7
作者：
Alcaide, Miguel;Edwards, Scott V.
通讯作者：
Edwards, Scott V.
使用下一代 DNA 测序数据进行变异发现和基因分型的框架。
影响因子：
30.8
作者：
通讯作者：
--
影响因子：
9.8
作者：
Browning, Brian L.;Zhou, Ying;Browning, Sharon R.
通讯作者：
Browning, Sharon R.