Department of Medical Biochemistry and Cell Biology, Institute of Biomedicine, Sahlgrenska Academy, University of Gothenburg, Box 440, Medicinaregatan 9C, 405 30, Gothenburg, Sweden.
Fish Pathology Group, Institute of Aquaculture Torre de la Sal (IATS, CSIC), Ribera de Cabanes s/n, 12595, Cabanes, Castellón, Spain; Nutrigenomics and Fish Growth Endocrinology Group, Institute of Aquaculture Torre de la Sal (IATS, CSIC), Ribera de Cabanes s/n, 12595, Cabanes, Castellón, Spain.
Fish Shellfish Immunol. 2024 Oct;153:109864. doi: 10.1016/j.fsi.2024.109864. Epub 2024 Aug 30.
Gilthead seabream (Sparus aurata) is a marine finfish of economic importance in aquaculture. Despite its adaptability to varying culture conditions, gilthead seabream culture can be affected by viral, bacterial or parasitic diseases. The main route of entry of pathogens is through mucosal surfaces. Teleost external and internal surfaces are covered by mucus, mainly comprised of highly glycosylated proteins called mucins. The mucin glycans regulate pathogen growth, adhesion, virulence and inter and intra species communication. Here, we characterized the gilthead seabream mucus glycosylation, compared it to previously described species and investigated associations with microbiota. 214 glycans were identified. The majority of the glycans were found at more than one epithelial surface, but 27, 22 and 89 O-glycan structures were unique to skin, gill and intestinal sample groups, respectively. Six O-glycan core types were observed. The majority of the seabream skin and gill O-glycans were neutral with unusual poly HexNAc motifs. In contrast, seabream intestinal O-glycans were highly acidic and not of the 'poly HexNAc' type observed in skin and gill. Furthermore, gilthead seabream gill mucosa had less oligomannose and more complex N-glycans compared to skin and intestine. The concentration and diversity of bacteria was similar in skin, gill and intestine, but the bacterial species differed between epithelia and co-varied with glycan epitopes. The presence of a complex mucus glycosylation with plenty of glycan epitopes for bacterial foraging, suggest that the skin mucosal defense in seabream includes an abundant resident microbiota. This large library of structures provides a platform for further studies, for example aiming to identifying glycans to use for diagnostic purposes, to study host-microbe interactions or disease intervention therapies.
金头鲷（Sparus aurata）是一种具有经济重要性的海水养殖鱼类。尽管它适应了不同的养殖条件，但金头鲷养殖仍可能受到病毒、细菌或寄生虫疾病的影响。病原体的主要进入途径是通过黏膜表面。硬骨鱼类的外部和内部表面都覆盖着黏液，主要由高度糖基化的蛋白质（称为粘蛋白）组成。粘蛋白糖链调节病原体的生长、黏附、毒力以及种间和种内的交流。在这里，我们描述了金头鲷的黏液糖基化，将其与之前描述的物种进行了比较，并研究了与微生物组的关联。鉴定出了 214 种糖链。大多数糖链存在于不止一个上皮表面，但 27、22 和 89 个 O-聚糖结构分别是皮肤、鳃和肠道样本组所特有的。观察到六种 O-聚糖核心类型。金头鲷皮肤和鳃的大多数 O-聚糖是中性的，具有不寻常的多己糖胺基序。相比之下，金头鲷肠道的 O-聚糖高度酸性，与皮肤和鳃中观察到的“多己糖胺”类型不同。此外，与皮肤和肠道相比，金头鲷鳃黏膜的寡甘露糖较少，而 N-聚糖较复杂。皮肤、鳃和肠道中的细菌浓度和多样性相似，但细菌种类在不同上皮组织之间存在差异，并与糖基化表位共同变化。丰富的糖基化和大量的细菌觅食糖基化表位表明，金头鲷的皮肤黏膜防御包括丰富的常驻微生物群。这些大量的结构为进一步的研究提供了一个平台，例如旨在识别用于诊断目的的聚糖，研究宿主-微生物相互作用或疾病干预疗法。
