Frederick Alyssa R, Heras Joseph, Friedman Carolyn S, German Donovan P
Department of Ecology and Evolutionary Biology, University of California, Irvine, 321 Steinhaus Hall, Irvine, CA 92697, USA.
Department of Ecology and Evolutionary Biology, University of California, Irvine, 321 Steinhaus Hall, Irvine, CA 92697, USA.
Comp Biochem Physiol Part D Genomics Proteomics. 2022 Mar;41:100930. doi: 10.1016/j.cbd.2021.100930. Epub 2021 Nov 8.
In the abalone and Candidatus Xenohaliotis californiensis (Ca. Xc) system, the Ca. Xc bacterium infects abalone digestive tissues and leads to extreme starvation and a characteristic "withering" of the gastropod foot. First identified in black abalone in California after an El Niño event, withering syndrome (WS) has caused large declines in wild black and captive white abalone on the northeastern Pacific coast, but disease resistance levels are species-, and possibly population-specific. This study compared gene expression patterns in the digestive gland of Ca. Xc-exposed and unexposed (control) Pinto abalone (Haliotis kamtschatkana), a particularly susceptible species. Lab-induced Ca. Xc infections were followed over 7 months and RNAseq was used to identify differential gene expression. Exposed Pinto abalone showed distinct changes in expression of 68 genes at 3 and 7 months post-infection relative to those in control animals. Upregulation of an orexin-like receptor (which is involved in feeding signaling) and a zinc peptidase-like region (many amino peptidases are zinc peptidases) in animals infected for 7 months indicates that animals with Ca. Xc infection may be starving and upregulating processes associated with feeding and digestion. Other groups of differentially expressed genes (DEGs) were upregulated or downregulated across control and exposed individuals over the 7-month experiment, including DEG groups that likely correspond to early disease state and to general stress response of being held in captivity. No patterns emerged in genes known to be involved in molluscan immune response, despite this being an expectation during a 7-month infection; digestion-related genes and unannotated DEGs were identified as targets for future research on potential immune response to WS in abalone.
在鲍鱼与加州拟嗜盐菌（Ca. Xc）的系统中，Ca. Xc细菌感染鲍鱼的消化组织，导致极度饥饿以及腹足纲动物足部出现特征性的“萎缩”。枯萎综合征（WS）在厄尔尼诺事件后首次在加利福尼亚的黑鲍鱼中被发现，它已导致东北太平洋沿岸野生黑鲍鱼和圈养白鲍鱼数量大幅下降，但抗病水平因物种而异，可能还因种群而异。本研究比较了受Ca. Xc感染和未受感染（对照）的平托鲍鱼（红鲍，Haliotis kamtschatkana）（一种特别易感的物种）消化腺中的基因表达模式。对实验室诱导的Ca. Xc感染进行了7个月的跟踪，并使用RNA测序来鉴定差异基因表达。与对照动物相比，受感染的平托鲍鱼在感染后3个月和7个月时，68个基因的表达出现了明显变化。感染7个月的动物中，一种食欲素样受体（参与进食信号传导）和一个锌肽酶样区域（许多氨肽酶是锌肽酶）的上调表明，感染Ca. Xc的动物可能处于饥饿状态，并上调了与进食和消化相关的过程。在为期7个月的实验中，其他差异表达基因（DEG）组在对照和受感染个体中上调或下调，包括可能对应于早期疾病状态和圈养一般应激反应的DEG组。尽管在7个月的感染过程中预期会出现这种情况，但在已知参与软体动物免疫反应的基因中未发现任何模式；与消化相关的基因和未注释的DEG被确定为未来研究鲍鱼对WS潜在免疫反应的目标。
