An initial comparative genomic autopsy of wasting disease in sea stars
An initial comparative genomic autopsy of wasting disease in sea stars
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DOI：
10.1111/mec.15386
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发表时间：
2020-02
影响因子：
4.9
通讯作者：
Dannise V. Ruiz‐Ramos;L. M. Schiebelhut;K. Hoff;J. Wares;M. Dawson
中科院分区：
文献类型：
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作者：
Dannise V. Ruiz‐Ramos;L. M. Schiebelhut;K. Hoff;J. Wares;M. Dawson
从2013年开始，整个北太平洋东部的海星被消耗性疾病所毁灭，由于其难以捉摸的病因，也被称为“小行星特发性消耗综合征”（AIWS）。AIWS的地理范围和分类规模意味着导致爆发的事件是异质的，多方面的，并且通常未被观察到;从发病到死亡的进展非常迅速，几乎没有留下任何症状。在这里，我们采取法医基因组学的方法来发现候选基因，可能有助于解释海星星消耗综合征。我们报告的第一个基因组和注释Pisaster赭色，沿着差异基因表达（DGE）分析，在四个大小类，三种组织类型，并在症状和无症状的个人。我们整合了与消耗性疾病爆发的幸存者相关的核苷酸多态性，与P. ochraceus中的温度处理相关的DGE，以及与另一个小行星Pycnopodia helianthoides中的消耗相关的DGE。在赭曲霉中，我们在所有组织中，在大小类别中，以及在无症状和有症状个体之间发现了DGE;最强的消耗相关DGE信号在幽门盲肠中。我们还发现先前鉴定的离群基因座与差异表达基因共存。在有症状和无症状个体的跨物种比较中，一致的反应区分了与无脊椎动物先天免疫和化学防御相关的基因，与环境依赖性应激反应、防御性细胞凋亡和组织降解一致。因此，我们的分析突出了可能将可疑的环境驱动因素（升高的温度）与个体之间的内在差异（年龄/大小，与易感性相关的等位基因）联系起来的基因组成分，这些差异引起生物体反应（例如，体腔细胞增殖）并表现为海星星星消耗性大规模死亡。
Beginning in 2013, sea stars throughout the Eastern North Pacific were decimated by wasting disease, also known as “asteroid idiopathic wasting syndrome” (AIWS) due to its elusive aetiology. The geographic extent and taxonomic scale of AIWS meant events leading up to the outbreak were heterogeneous, multifaceted, and oftentimes unobserved; progression from morbidity to death was rapid, leaving few tell‐tale symptoms. Here, we take a forensic genomic approach to discover candidate genes that may help explain sea star wasting syndrome. We report the first genome and annotation for Pisaster ochraceus, along with differential gene expression (DGE) analyses in four size classes, three tissue types, and in symptomatic and asymptomatic individuals. We integrate nucleotide polymorphisms associated with survivors of the wasting disease outbreak, DGE associated with temperature treatments in P. ochraceus, and DGE associated with wasting in another asteroid Pycnopodia helianthoides. In P. ochraceus, we found DGE across all tissues, among size classes, and between asymptomatic and symptomatic individuals; the strongest wasting‐associated DGE signal was in pyloric caecum. We also found previously identified outlier loci co‐occur with differentially expressed genes. In cross‐species comparisons of symptomatic and asymptomatic individuals, consistent responses distinguish genes associated with invertebrate innate immunity and chemical defence, consistent with context‐dependent stress responses, defensive apoptosis, and tissue degradation. Our analyses thus highlight genomic constituents that may link suspected environmental drivers (elevated temperature) with intrinsic differences among individuals (age/size, alleles associated with susceptibility) that elicit organismal responses (e.g., coelomocyte proliferation) and manifest as sea star wasting mass mortality.