Plumage color and pathogen-induced gene expression in a wild bird
Plumage color and pathogen-induced gene expression in a wild bird
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DOI：
10.1093/beheco/arv055
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发表时间：
2015-07-01
影响因子：
2.4
通讯作者：
Hill, Geoffrey E.
中科院分区：
文献类型：
--
作者：
Balenger, Susan L.;Bonneaud, Camille;Hill, Geoffrey E.
雌性根据对寄生虫的抗性特征选择配偶，可以为后代获得抗性基因。目前还不知道直接将装饰物和疾病反应联系起来的基因。在家雀中，羽毛颜色是选择雌性的一个重要标准，病原体感染会影响颜色。我们测量了雄性对细菌感染的分子反应，这些雄性具有更多和更少的偏好颜色，并确定了几个将装饰质量与疾病反应联系起来的基因，假设装饰是个体科普环境挑战的能力的信号。在分子水平上，生物体主要通过改变基因转录来对环境做出反应，但将基因表达与抗病性联系起来的转录反应几乎未被研究。在家雀（Haemorhous mexicanus）中，雄性所显示的类胡萝卜素着色在雌性选择中很重要，羽毛发红预示着雄性从鸡毒支原体细菌感染中恢复的能力。为了研究免疫和疾病反应之间联系的分子机制，我们实验性地感染了野生雀，并使用微阵列来识别在羽毛颜色更红和更黄的雄性中差异表达的基因。然后在个体中研究了16个候选基因。主成分分析显示，感染引起11个基因的轻微显着下降，其中几个具有主要的免疫功能。通过羽色互作效应的处理在很大程度上是由疾病引起的红鸟比黄鸟热休克蛋白90和泛素c（第二主成分）表达的变化更大所驱动的。在直接比较受感染鸟类之间的疾病严重程度时，羽毛颜色本身并不能显著预测疾病症状。然而，在多变量模型中，第二主成分，羽毛颜色，以及它们的相互作用的基因加载的表达是疾病症状的严重程度的显着预测。我们的观察结果表明，与抗病相关的基因的表达之间的联系，我们认为，男性羽毛的颜色可能反映功能相关的差异，在这个物种的基因表达的诱导或可塑性。
Females choosing mates based on traits that indicate resistance to parasites can obtain genes for resistance for their offspring. Genes that directly link ornaments and disease response are not yet known. In the house finch, plumage color is an important criterion in female choice, and pathogen infection affects coloration. We measured molecular responses to bacterial infection by males with more and less preferred coloration and identify several genes linking quality of ornamentation to disease response.Ornamentation is hypothesized to signal the capacity of an individual to cope with environmental challenges. At the molecular level, organisms respond to their environments largely by altering gene transcription, but the transcriptional responses linking ornamentation and disease resistance are virtually unstudied. In the house finch (Haemorhous mexicanus), carotenoid coloration displayed by males is important in female choice, and plumage redness predicts a male's ability to recover from bacterial infection with Mycoplasma gallisepticum. To investigate the molecular mechanisms underlying links between ornamentation and disease response, we experimentally infected wild finches and used microarrays to identify genes that were differentially expressed in males with redder and yellower plumage coloration. Sixteen candidate genes were then investigated across individuals. Principal components analysis revealed that infection induced a marginally significant decrease in 11 genes, several with primary immune functions. The treatment by plumage color interaction effect was largely driven by greater disease-induced changes in expression of heat shock protein 90 and ubiquitin c (the second principal component) by red birds than by yellow birds. In a direct comparison of disease severity between infected birds, plumage color on its own did not significantly predict disease symptoms. However, in multivariate models, expression of genes loading on the second principal component, plumage color, and their interaction were significant predictors of the severity of disease symptoms. Our observations demonstrate links between ornamentation and expression of genes related to disease resistance; we suggest that male plumage color may reflect functionally associated differences in inducibility or plasticity of gene expression in this species.