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 etiology. 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 P. 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 find DGE across all tissues, among size classes, and between asymptomatic and symptomatic individuals; the strongest wasting-associated DGE signal is in pyloric caecum. We also find 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 defense, 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.

中文翻译：

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消灭海星疾病的初步比较基因组尸检。

从2013年开始，北太平洋东部的海星因消瘦疾病而致死，由于病因不明，该疾病也被称为“小行星特发性消瘦综合症”（AIWS）。AIWS的地理范围和分类学规模意味着导致疫情爆发的事件是异类的，多方面的，而且常常是不可观测的。从发病到死亡的进展很快，几乎没有明显的症状。在这里，我们采用法医基因组学方法来发现候选基因，这可能有助于解释海星浪费综合征。我们报告第一个基因组和草的注释，以及在四个大小类别，三种组织类型以及有症状和无症状个体中的差异基因表达（DGE）分析。我们整合了与浪费性疾病暴发幸存者相关的核苷酸多态性，DGE与骨对虾的温度处理有关，而DGE与另一种小行星拟南芥（Pycnopodia helianthoides）的浪费有关。在桐中，我们发现所有组织中，大小等级之间，无症状和有症状个体之间的DGE。与消化不良相关的最强信号是幽门盲肠。我们还发现以前鉴定的异常基因座与差异表达的基因同时发生。在有症状和无症状个体的跨物种比较中，一致的应答区分与无脊椎动物先天免疫和化学防御相关的基因，与上下文相关的应激应答，防御性凋亡和组织降解一致。