Wei Jinfen, Fan Sigang, Liu Baosuo, Zhang Bo, Su Jiaqi, Yu Dahui
Qinzhou University, Qinzhou 535011, Guangxi, China; Key Laboratory of South China Sea Fishery Resources Exploitation & Utilization, Ministry of Agriculture, South China Sea Fisheries Research Institute, Chinese Academy of Fishery Sciences, Guangzhou 510300, China; College of Fisheries and Life Science, Shanghai Ocean University, Shanghai 201306, China.
Key Laboratory of South China Sea Fishery Resources Exploitation & Utilization, Ministry of Agriculture, South China Sea Fisheries Research Institute, Chinese Academy of Fishery Sciences, Guangzhou 510300, China.
Fish Shellfish Immunol. 2017 Aug;67:331-345. doi: 10.1016/j.fsi.2017.06.030. Epub 2017 Jun 9.
The pearl oyster Pinctada maxima exhibits great difficulty to culture pearls through nuclear insertion with an allograft, but it is easy for P. fucata to culture pearls after allografting. If P. fucata could be used as a surrogate mother to culture P. maxima pearls, it would benefit the pearl culture industry of P. maxima. However, this is blocked by the immune rejection of P. fucata against P. maxima mantle grafts. In this study, the immune responses of P. fucata hemocyte to allograft and xenograft were investigated after transplantation by transcriptome analysis. In total, 107.93 Gb clean reads were produced and assembled using the reference genome of P. fucata. Gene Ontology Term enrichment and KEGG enrichment analyses indicated that apoptosis, hippo signaling pathway, oxidation-reduction, MAPK signaling pathway, ribosome, protein processing in endoplasmic reticulum, purine metabolism, NF-kappa B signaling pathway, oxidative phosphorylation, Ras signaling pathway, and ubiquitin mediated proteolysis were involved in response to transplantation. Many genes related to oxidation-reduction reactions, the MAPK signaling pathway, and apoptosis were identified by comparison of the allograft group and the xenograft group at 0 h, 6 h, 12 h, 24 h, 48 h, 72 h, and 96 h post-transplantation. Among them, the expression levels of NADH dehydrogenase, succinate dehydrogenase and other dehydrogenases were increased significantly in the xenograft groups compared with allograft groups at 0 h post transplantation, indicating that a respiratory burst of neutrophils occurred immediately after xenograft transplantation. Additionally, HSP70 was highly expressed from 0 h to 96 h in the xenograft groups, indicating an oyster immune response to the xenograft. The genes enriched in the ribosome and hippo-signaling pathways were also identified, and expression patterns of these DEGs were different as compared between transplantation and control groups. Finally, altered expression levels of 10 randomly selected immune-related DEGs were confirmed by quantitative real-time PCR. These results indicated that oxidation-reduction is likely the key factor responsible for immune rejection to transplantation. The findings should provide some new insight into the molecular mechanism of immune rejection of the host against xenograft, and thus benefit to development of immunosuppressive reagents to facilitate effective xenograft pearling.
大珠母贝通过同种异体移植核植入培育珍珠存在很大困难，但合浦珠母贝在同种异体移植后培育珍珠却很容易。如果能用合浦珠母贝作为代孕母体来培育大珠母贝珍珠，将有利于大珠母贝珍珠养殖业。然而，这受到合浦珠母贝对大珠母贝外套膜移植的免疫排斥的阻碍。在本研究中，通过转录组分析研究了合浦珠母贝血细胞在移植后对同种异体移植和异种移植的免疫反应。总共产生了107.93 Gb的clean reads，并使用合浦珠母贝的参考基因组进行组装。基因本体论术语富集分析和KEGG富集分析表明，细胞凋亡、河马信号通路、氧化还原、丝裂原活化蛋白激酶信号通路、核糖体、内质网中的蛋白质加工、嘌呤代谢、核因子κB信号通路、氧化磷酸化、Ras信号通路和泛素介导的蛋白水解参与了对移植的反应。通过比较同种异体移植组和异种移植组在移植后0小时、6小时、12小时、24小时、48小时、72小时和96小时，鉴定出许多与氧化还原反应、丝裂原活化蛋白激酶信号通路和细胞凋亡相关的基因。其中，与同种异体移植组相比，异种移植组在移植后0小时NADH脱氢酶、琥珀酸脱氢酶等脱氢酶的表达水平显著升高，表明异种移植后中性粒细胞立即发生呼吸爆发。此外，HSP70在异种移植组中从0小时到96小时高表达，表明牡蛎对异种移植有免疫反应。还鉴定了核糖体和河马信号通路中富集的基因，并且这些差异表达基因在移植组和对照组之间的表达模式不同。最后，通过定量实时PCR证实了10个随机选择的免疫相关差异表达基因的表达水平发生了改变。这些结果表明氧化还原可能是导致对移植免疫排斥的关键因素。这些发现应为宿主对异种移植免疫排斥的分子机制提供一些新的见解，从而有利于开发免疫抑制试剂以促进有效的异种移植珍珠培育。
