scholarly journals Polyamine Putrescine Regulates Oxidative Stress and Autophagy of Hemocytes Induced by Lipopolysaccharides in Pearl Oyster Pinctada fucata martensii

2021 ◽  
Vol 12 ◽  
Author(s):  
Yanfei Cao ◽  
Yu Jiao ◽  
Shuzhi Zhan ◽  
Xueru Liang ◽  
Zhixin Li ◽  
...  
Keyword(s):  
Immunosuppressive Agents ◽  
Combined Treatment ◽  
Mammalian Target Of Rapamycin ◽  
Pearl Oyster ◽  
Pinctada Fucata ◽  
Janus Kinase ◽  
Iκb Kinase ◽  
Pearl Oysters ◽  
Amp Activated Protein Kinase ◽  
Oxide Synthase

The polyamine putrescine (Put) is a ubiquitous small cationic amine. It plays an essential role in controlling the innate immune response. However, little is known about its function in mollusks. In this study, the Put content was observed to increase in the serum of pearl oyster Pinctada fucata martensii after 6 and 24 h of lipopolysaccharide (LPS) stimulation. Activities of superoxide dismutase (SOD), catalase (CAT), and glutathione peroxidase (GSH-Px) increased, and nitric oxide synthase was downregulated in the Put group (i.e., combined treatment with Put and LPS) compared with that in the LPS group (i.e., combined treatment with phosphate-buffered saline and LPS). Furthermore, activities of alkaline phosphatase and acid phosphatase were inhibited after 6 h of LPS stimulation. The expression levels of the nuclear factor kappa B, IκB kinase, Janus kinase, and signal transducer and activator of transcription proteins genes were all significantly suppressed at 12 and 24 h in the Put group. Pseudomonas aeruginosa and Bacillus subtilis grew better after being incubated with the serum from the Put group than that from the LPS group. Additionally, the Put treatment remarkably inhibited the autophagy of hemocytes mediated by the AMP-activated protein kinase-mammalian target of rapamycin-Beclin-1 pathway. This study demonstrated that Put can effectively inhibit the inflammatory response induced by LPS in pearl oysters. These results provide useful information for further exploration of the immunoregulatory functions of polyamines in bivalves and contribute to the development of immunosuppressive agents.

scholarly journals Mass mortality of pearl oyster (Pinctada fucata (Gould)) in Japan in 2019 and 2020 is caused by an unidentified infectious agent

PeerJ ◽  
2021 ◽  
Vol 9 ◽  
pp. e12180
Author(s):  
Tomomasa Matsuyama ◽  
Satoshi Miwa ◽  
Tohru Mekata ◽  
Yuta Matsuura ◽  
Tomokazu Takano ◽  
...  
Keyword(s):  
Infectious Agent ◽  
Serial Passage ◽  
Pearl Oyster ◽  
Mass Mortality ◽  
Pinctada Fucata ◽  
Enveloped Virus ◽  
Pearl Oysters ◽  
Adult Oyster ◽  
Sources Of Infection ◽  
Pathogen Occurrence

Mass mortality of 0-year-old pearl oysters, Pinctada fucata (Gould), and anomalies in adults were observed in Japan’s major pearl farming areas in the summer of 2019 and 2020. Although adult oyster mortality was low, both adult and juvenile oysters underwent atrophy of the soft body, detachment of the mantle from nacre (the shiny inner surface of the valves), deposition of brownish material on the nacre, and loss of nacre luster. Infection trials were conducted to verify the involvement of pathogens in this phenomenon. Healthy adult pearl oysters were obtained from areas where this disease had not occurred to use as the recipients. The sources of infection were either affected adult oysters with atrophied soft bodies or batches of juveniles in which mortality had reached conspicuous levels. Transmission of the disease to the healthy oysters were tested either by cohabitation with affected oysters or by injections of the hemolymph of affected animals. The injection infection test examined the effects of filtration and chloroform exposure on the pathogen. Occurrence of the disease was confirmed by the appearance of brown deposits on the nacre and loss of nacre luster. The abnormalities of nacre were clearly reproduced in recipient shells in three out of four cohabitation trials with affected oysters. The disease was also reproduced in six out of six injection trails either with hemolymph filtered through 100 nm filter or with hemolymph treated with chloroform. In a serial passage with hemolymph injections, the disease was successfully transmitted through eight passages. These results suggest that the etiology of the disease is a non-enveloped virus with a diameter ≤100 nm.

scholarly journals Microbiota Diversity in Pearl Oyster Pinctada fucata martensii Intestine and Its Aquaculture Environment

2021 ◽  
Vol 8 ◽  
Author(s):  
Zhe Zheng ◽  
Yongshan Liao ◽  
Jianming Ye ◽  
Chuangye Yang ◽  
Linda Adzigbli ◽  
...  
Keyword(s):  
Amino Acids ◽  
Intestinal Microbiota ◽  
Bacterial Communities ◽  
Pearl Oyster ◽  
Pinctada Fucata ◽  
Sequencing Data ◽  
Surrounding Water ◽  
Core Microbiome ◽  
Pearl Oysters ◽  
Surrounding Seawater

Environmental microbiota plays a vital role in the intestinal microbiota of aquatic organisms. However, data concerning the association between the intestinal microbiota of pearl oyster Pinctada fucata martensii and the surrounding seawater are limited. The existing bacterial communities in pearl oyster intestine and surrounding water from two sites (D and H, within Liusha Bay in Guangdong, China) were investigated using 16S rRNA-based sequencing to explore the relationship among the two. D located in the inner bay, and H located in the open sea area outside bay. Results revealed the richness and diversity of pearl oyster intestinal microbiota to be less than those of the surrounding water, with 38 phyla and 272 genera observed as a result of the classifiable sequence. The microbiota compositions in the intestine and the surrounding water were diversified at the phylum and genus levels, with the sequencing data being statistically significant. However, the functional prediction of microbiota emphasized the overall similarity in the functional profile of the surrounding seawater and intestinal microbiomes. This profile was associated with metabolism of cofactors and vitamin, carbohydrates metabolism, amino acids metabolism, metabolism of terpenoids, and polyketides, metabolism of other amino acids, lipids metabolism, and energy metabolism. Seven common operational taxonomic units (OTUs), which belonged to phyla Tenericutes, Cyanobacteria, and Planctomycetes, were noted in the intestines of pearl oysters from two different sites. These OTUs may be affiliates to the core microbiome of pearl oyster. Significantly different bacterial taxa in the intestines of pearl oysters from two different sites were found at the phylum and genus levels. This finding suggested that the bacterial communities in pearl oyster intestines may exhibit some plasticity to adapt to changes in the surrounding water-cultured environment. This study generally offers constructive discoveries associated with pearl oyster intestinal microbiota and provides guidance for sustainable aquaculture.

scholarly journals ​Isolation and Characterization of a Vibrio Sp. Strain MA3 Possibly Associated with Mass Mortalities of the Pearl Oyster Pinctada fucata

2021 ◽  
Author(s):  
Akihiro SAKATOKU ◽  
Kaito Hatano ◽  
Shoki Tanaka ◽  
Tadashi Isshiki
Keyword(s):  
Soft Tissues ◽  
Morphological Characteristics ◽  
Pearl Oyster ◽  
Vibrio Alginolyticus ◽  
Pinctada Fucata ◽  
Causative Organism ◽  
Rrna Gene ◽  
Isolation And Characterization ◽  
Pearl Oysters ◽  
Mass Mortalities

Abstract In the summers of 2019 and 2020, a previously undescribed disease occurred in both juvenile and adult shellfish, causing mass mortalities in cultured pearl production, characterized by the major symptom of extreme atrophy of the soft tissues, including the mantle. However, the causative organism was uncertain. We isolated Vibrio sp. strain MA3 from the mantles of diseased pearl oysters Pinctada fucata. Analyses of 16S rRNA gene and DNA gyrase sequence homologies and its biochemical and morphological characteristics suggested that strain MA3 is a new strain of Vibrio alginolyticus. In addition, a hemolysin gene (Vhe1) of strain MA3 was detected as one of the virulence factors, and the complete sequence was determined. BLAST searches showed that Vhe1 shares 99.8% nucleotide sequence identity with Vibrio alginolyticus strain A056 lecithin-dependent hemolysin (ldh) gene, complete cds. Experimental infection of healthy oysters via injection with strain MA3 indicated it could cause high mortalities of the typically affected oysters from which the strain was isolated. These results suggest that the newly isolated Vibrio sp. strain MA3 is a putative causal agent of the recent disease outbreaks in Akoya pearl oysters.

scholarly journals Comparison in Growth, Feeding, and Metabolism Between a Fast-Growing Selective Strain and a Cultured Population of Pearl Oyster (Pinctada fucata martensii)

2021 ◽  
Vol 8 ◽  
Author(s):  
Xingzhi Zhang ◽  
Bingcong Ye ◽  
Zhifeng Gu ◽  
Meng Li ◽  
Shouguo Yang ◽  
...  
Keyword(s):  
Growth Rate ◽  
Rapid Growth ◽  
Ammonia Excretion ◽  
High Growth ◽  
Pearl Oyster ◽  
Pinctada Fucata ◽  
Production Traits ◽  
Slow Growth Rate ◽  
Fast Growing ◽  
Pearl Oysters

Pearl oyster (Pinctada fucata martensii) is the main species cultured for marine pearls in the world. A breeding program was carried out for desirable production traits, including high growth rate, and a fast-growing selective strain of pearl oysters was established. In the current study, we compared the growth characteristics between a selective strain and a cultured population of P. f. martensii in Beihai, Guangxi Province, China. Large size (SL) and small size (SS) individuals of the selective strain were selected, and the differences of physiological and metabolic indexes, such as feeding, respiration, excretion, and enzyme activities between SL and SS and cultured population (CL), were also compared. The results showed that at the age of 6 months, pearl oysters of the selective strain were 14.61% larger than CL, and the proportion of SL (30–40 mm) was 59%, which was two times higher than CL (28%). SL with a rapid growth rate had a high clearance rate (CR), and the CR of SL was about 1.8 times higher than that of CL and 5 times higher than that of SS. In addition, the activities of digestive enzymes (amylase, pepsin, and lipase) and growth-related carbonic anhydrase enzymes in SL were higher than those in the other two groups (p < 0.05). SS with a slow growth rate had higher oxygen consumption (OCR) and ammonia excretion (AER) rates than SL and CL (p < 0.05). Our results suggest that the rapid growth of the selective strain P. f. martensii can be attributed to increased energy intake and reduced energy consumption.

scholarly journals Integrated GC–MS- and LC–MS-Based Untargeted Metabolomics Studies of the Effect of Vitamin D3 on Pearl Production Traits in Pearl Oyster Pinctada fucata martensii

2021 ◽  
Vol 8 ◽  
Author(s):  
Chuangye Yang ◽  
Yetao Zeng ◽  
Yongshan Liao ◽  
Yuewen Deng ◽  
Xiaodong Du ◽  
...  
Keyword(s):  
Vitamin D3 ◽  
Retention Rate ◽  
Sugar Metabolism ◽  
Pearl Oyster ◽  
Pinctada Fucata ◽  
Dietary Vitamin ◽  
Control Group ◽  
Production Traits ◽  
High Quality ◽  
Pearl Oysters

Pearl oyster Pinctada fucata martensii is widely recognized for biomineralization and has been cultured for high-quality marine pearl production. To ascertain how dietary vitamin D3 (VD3) levels affect the features of pearl production by P. f. martensii and discover the mechanisms regulating this occurrence, five experimental diets with variable levels of VD3 were used with inclusion levels of 0, 500, 1,000, 3,000, and 10,000 IU/kg. The distinct inclusion levels were distributed into five experimental groups (EG1, EG2, EG3, EG4, and EG5). All the experimental groups were reared indoors except the control group (CG) reared at the sea. Pearl oysters, one year and a half old, were used in the grafting operation to culture pearls. During the growing period that lasted 137 days, EG3 had the highest survival rate, retention rate, and high-quality pearl rate. A similar trend was found for EG3 and CG with significantly higher pearl thickness and nacre deposition rates than other groups, but no significant differences were observed between them. A metabolomics profiling using GC–MS and LC–MS of pearl oysters fed with low quantities of dietary VD3 and optimal levels of dietary VD3 revealed 135 statistically differential metabolites (SDMs) (VIP > 1 and p < 0.05). Pathway analysis indicated that SDMs were involved in 32 pathways, such as phenylalanine metabolism, histidine metabolism, glycerophospholipid metabolism, alanine aspartate and glutamate metabolism, arginine and proline metabolism, glycerolipid metabolism, amino sugar and nucleotide sugar metabolism, and tyrosine metabolism. These results provide a theoretical foundation for understanding the impacts of VD3 on pearl production traits in pearl oyster and reinforce forthcoming prospects and application of VD3 in pearl oyster in aquaculture rearing conditions.

Establishment and genetic analysis of complete diallel cross families of pearl oyster (Pinctada fucata)

2010 ◽  
Vol 34 (1) ◽  
pp. 26-31
Author(s):  
Long-chun GU ◽  
Jin-bi LI ◽  
Da-hui YU ◽  
Gui-ju HUANG ◽  
Jian-ye LIU
Keyword(s):  
Genetic Analysis ◽  
Diallel Cross ◽  
Pearl Oyster ◽  
Pinctada Fucata ◽  
Complete Diallel Cross

The role of Smad1/5 in mantle immunity of the pearl oyster Pinctada fucata martensii

2021 ◽  
Vol 113 ◽  
pp. 208-215
Author(s):  
Yu Shi ◽  
Xiaolan Pan ◽  
Meng Xu ◽  
Huiru Liu ◽  
Hanzhi Xu ◽  
...  
Keyword(s):  
Pearl Oyster ◽  
Pinctada Fucata

scholarly journals Salmonella Impacts Tumor-Induced Macrophage Polarization, and Inhibits SNAI1-Mediated Metastasis in Melanoma

Cancers ◽  
2021 ◽  
Vol 13 (12) ◽  
pp. 2894
Author(s):  
Christian R. Pangilinan ◽  
Li-Hsien Wu ◽  
Che-Hsin Lee
Keyword(s):  
Epithelial To Mesenchymal Transition ◽  
Lung Metastases ◽  
Macrophage Polarization ◽  
Interleukin 1 ◽  
Mammalian Target Of Rapamycin ◽  
High Mobility ◽  
Treated Group ◽  
Mesenchymal Transition ◽  
Oxide Synthase

Targeting metastasis is a vital strategy to improve the clinical outcome of cancer patients, specifically in cases with high-grade malignancies. Here, we employed a Salmonella-based treatment to address metastasis. The potential of Salmonella as an anticancer agent has been extensively studied; however, the mechanism through which it affects metastasis remains unclear. This study found that the epithelial-to-mesenchymal transition (EMT) inducer SNAI1 was markedly reduced in Salmonella-treated melanoma cells, as revealed by immunoblotting. Furthermore, wound healing and transwell assays showed a reduced in vitro cell migration following Salmonella treatment. Transfection experiments confirmed that Salmonella acted against metastasis by suppressing protein kinase B (Akt)/mammalian target of rapamycin (mTOR) signaling, which in turn inhibited SNAI1 expression. Since it is known that metastasis is also influenced by inflammation, we partly characterized the immune infiltrates in melanoma as affected by Salmonella treatment. We found through tumor-macrophage co-culture that Salmonella treatment increased high mobility group box 1 (HMGB1) secretion in tumors to coax the polarization of macrophages in favor of an M1-like phenotype, as shown by increased inducible nitric oxide synthase (iNOS) expression and Interleukin 1 Beta (IL-1β) secretion. Data from our animal study corroborated the in vitro findings, wherein the Salmonella-treated group obtained the lowest lung metastases, longer survival, and increased iNOS-expressing immune infiltrates.

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