PDF(Pubmed)
Abstract：
Vibriosis is one of the most serious diseases that commonly occurs in aquatic animals, thus, shaping a steady inherited resistance trait in organisms has received the highest priority in aquaculture. Whereas, the mechanisms underlying the development of such a resistance trait are mostly elusive. In this study, we constructed vibriosis-resistant and susceptible families of the Pacific white shrimp Litopenaeus vannamei after four generations of artificial selection. Microbiome sequencing indicated that shrimp can successfully develop a colonization resistance trait against Vibrio infections. This trait was characterized by a microbial community structure with specific enrichment of a single probiotic species (namely Shewanella algae), and notably, its formation was inheritable and might be memorized by host epigenetic remodeling. Regardless of the infection status, a group of genes was specifically activated in the resistant family through disruption of complete methylation. Specifically, hypo-methylation and hyper-expression of genes related to lactate dehydrogenase (LDH) and iron homeostasis might provide rich sources of specific carbon (lactate) and ions for the colonization of S. algae, which directly results in the reduction of Vibrio load in shrimp. Lactate feeding increased the survival of shrimp, while knockdown of LDH gene decreased the survival when shrimp was infected by Vibrio pathogens. In addition, treatment of shrimp with the methyltransferase inhibitor 5-azacytidine resulted in upregulations of LDH and some protein processing genes, significant enrichment of S. algae, and simultaneous reduction of Vibrio in shrimp. Our results suggest that the colonization resistance can be memorized as epigenetic information by the host, which has played a pivotal role in vibriosis resistance. The findings of this study will aid in disease control and the selection of superior lines of shrimp with high disease resistance.
摘要：
弧菌病是水生动物常见的最严重的疾病之一，因此，在生物中形成稳定的遗传抗性性状已在水产养殖中获得最高优先级。然而,这种抗性性状发展的潜在机制大多难以捉摸。在这项研究中,经过四代人工选择，我们构建了太平洋白虾凡纳滨对虾的抗弧菌病和易感家族。微生物组测序表明，虾可以成功地发展出针对弧菌感染的定植抗性性状。该性状的特征是微生物群落结构，具有单一益生菌物种（即希瓦氏菌藻类）的特定富集，尤其是,它的形成是可遗传的，可能通过宿主表观遗传重塑来记忆。不管感染状况如何,通过完全甲基化的破坏，一组基因在抗性家族中被特异性激活。具体来说,与乳酸脱氢酶（LDH）和铁稳态相关的基因的低甲基化和高表达可能为S.藻类的定殖提供丰富的特定碳（乳酸）和离子来源，这直接导致虾中弧菌负荷的减少。乳酸盐喂养增加了虾的存活率，而LDH基因的敲除降低了对虾被弧菌病原体感染时的存活率。此外,用甲基转移酶抑制剂5-氮杂胞苷处理虾导致LDH和一些蛋白质加工基因上调，藻类的显著富集，同时减少虾中的弧菌。我们的结果表明，定植抗性可以被宿主记忆为表观遗传信息，在抗弧菌病方面发挥了关键作用。这项研究的发现将有助于疾病控制和选择具有高抗病性的对虾的优良品系。
