Laboratório de Imunologia e Patologia de Invertebrados, Departamento de Biologia Molecular, Universidade Federal da Paraíba, CEP 58051-900, João Pessoa, PB, Brazil.
Laboratório de Genética Molecular Humana, Departamento de Biologia Molecular, Universidade Federal da Paraíba, CEP 58051-900, João Pessoa, PB, Brazil.
J Invertebr Pathol. 2017 Oct;149:76-81. doi: 10.1016/j.jip.2017.08.007. Epub 2017 Aug 8.
Bivalves are filter feeders that obtain food from seawater that may contain infectious agents, such as the protozoan parasites Perkinsus marinus and P. olseni that are associated with massive mortalities responsible for losses in the aquaculture industry. Despite all physical and chemical barriers, microorganisms cross epithelia and infect host tissues to cause pathologies. Epigenetics mechanisms play important roles in a variety of human processes, from embryonic development to cell differentiation and growth. It is currently emerging as crucial mechanism involved in modulation of host-parasite interactions and pathogenesis, promoting discovery of targets for drug treatment. In bivalves, little is known about epigenetic mechanism in host parasite interactions. The objective of the present study was to evaluate the effect of Perkinsus sp. infections on DNA methylation levels in tissues of Crassostrea gasar oysters. Samples were collected in 2015 and 2016 in the Mamanguape River estuary (PB). Oyster gills were removed and used for Perkinsus sp.
Gills (G) and gastrointestinal tract (GT), as well as cultured P. marinus trophozoites were preserved in 95% ethanol for DNA extractions. DNA methylation levels were estimated from G and GT tissues of uninfected (n=60) and infected oysters (n=60), and from P. marinus trophozoites, by ELISA assays. Results showed that the mean prevalence of Perkinsus sp. infections was high (87.3%) in 2015 and moderate (59.6%) in 2016. DNA methylation levels of G and GT tissues were significantly lower in infected oyster than in uninfected oysters, suggesting that infections are associated with hypomethylation. Methylation level was significantly higher in G than in GT tissues, indicating a likely tissue-specific mechanism. P. marinus trophozoites showed 33% methylation. This was the first study that confirms alterations of DNA methylation in two tissues of C. gasar oysters in association with Perkinsus sp. infections.
双壳贝类是滤食动物，它们从可能含有感染因子的海水中获取食物，例如原生动物寄生虫海扇贝虫和 P. olseni，这些寄生虫与导致水产养殖业损失的大规模死亡有关。尽管存在所有物理和化学屏障，微生物仍会穿过上皮细胞并感染宿主组织，导致病理学发生。表观遗传机制在多种人类过程中发挥着重要作用，从胚胎发育到细胞分化和生长。目前，它已成为宿主-寄生虫相互作用和发病机制调节的关键机制，促进了药物治疗靶点的发现。在双壳贝类中，关于宿主-寄生虫相互作用中的表观遗传机制知之甚少。本研究的目的是评估 Perkinsus sp. 感染对 Crassostrea gasar 牡蛎组织中 DNA 甲基化水平的影响。样本于 2015 年和 2016 年在 Mamanguape 河口（PB）采集。取出牡蛎鳃并用于 Perkinsus sp. 诊断：鳃 (G) 和胃肠道 (GT) 以及培养的 P. marinus 滋养体保存在 95%乙醇中用于 DNA 提取。通过 ELISA 测定未感染 (n=60) 和感染牡蛎 (n=60) 的 G 和 GT 组织以及 P. marinus 滋养体的 DNA 甲基化水平。结果表明，2015 年 Perkinsus sp. 感染的平均流行率很高 (87.3%)，2016 年中度流行 (59.6%)。与未感染的牡蛎相比，感染牡蛎的 G 和 GT 组织的 DNA 甲基化水平显着降低，表明感染与低甲基化有关。G 组织的甲基化水平显着高于 GT 组织，表明存在组织特异性机制。P. marinus 滋养体的甲基化率为 33%。这是第一项证实 C. gasar 牡蛎两种组织的 DNA 甲基化与 Perkinsus sp. 感染相关的研究。
