scholarly journals LECT2 Protects Nile Tilapia (Oreochromis niloticus) Against Streptococcus agalatiae Infection

2021 ◽  
Vol 12 ◽  
Author(s):  
Qi Li ◽  
Zhiqiang Zhang ◽  
Weiqi Fan ◽  
Yongxiong Huang ◽  
Jinzhong Niu ◽  
...  
Keyword(s):  
Immune Response ◽  
Bacterial Infection ◽  
Oreochromis Niloticus ◽  
Nile Tilapia ◽  
Head Kidney ◽  
Transcriptional Level ◽  
Reading Frame ◽  
Tissue Damages

Leukocyte cell-derived chemotaxin 2 (LECT2) is a multifunctional cytokine that especially plays an important role in innate immune. However, the roles of LECT2 in the immune response of the economically important fish Nile tilapia (Oreochromis niloticus) against bacterial infection remains unclear. In this study, a lect2 gene from Nile tilapia (On-lect2) was identified, and its roles in the fish’s immune response against bacterial infection were determined and characterised. On-lect2 contains an open reading frame of 456 bp that encodes a peptide of 151 amino acids, as well as the conservative peptidase M23 domain. On-LECT2 is 62%–84% identical to other fish species and about 50% identical to mammals. The highest transcriptional level of On-lect2 was detected in the liver, whereas the lowest levels were detected in the other tissues. Moreover, the On-LECT2 protein is located mainly in the brain and head kidney. The transcriptional levels of On-lect2 substantially increased in the head kidney, brain, liver and spleen after Streptococcus agalactiae infection. Knockdown On-lect2 led to higher mortality due to liver necrosis or haemorrhage and splenomegaly. In vitro analysis indicated that the recombinant protein of On-LECT2 improved phagocytic activity of head kidney-derived macrophages. In vivo challenge experiments revealed several functions of On-LECT2 in the immune response of Nile tilapia against bacterial infection, including promotion of inflammation, reduction of tissue damages and improvement of survival rate.

The in vivo roles of galectin-2 from Nile tilapia (Oreochromis niloticus) in immune response against bacterial infection

2020 ◽  
Vol 106 ◽  
pp. 473-479
Author(s):  
Jinzhong Niu ◽  
Xinchao Liu ◽  
Zhiqiang Zhang ◽  
Yu Huang ◽  
Jufen Tang ◽  
...  
Keyword(s):  
Immune Response ◽  
Bacterial Infection ◽  
Oreochromis Niloticus ◽  
Nile Tilapia ◽  
Nile Tilapia Oreochromis Niloticus

scholarly journals OASL Triggered by Novel Goose Astrovirus via ORF2 Restricts Its Replication

2020 ◽  
Vol 94 (24) ◽  
Author(s):  
Dan Ren ◽  
Tuofan Li ◽  
Xinyu Zhang ◽  
Xiaohui Yao ◽  
Wei Gao ◽  
...  
Keyword(s):  
Immune Response ◽  
Reading Frame ◽  
Enteric Diseases ◽  
C Terminus ◽  
Orf2 Protein ◽  
High Level ◽  
Antiviral Targets ◽  
Open Reading Frame 2

ABSTRACT Although astroviruses causes enteric diseases and encephalitis in humans and nephritis and hepatitis in poultry, astrovirus infection is thought to be self-limiting. However, little is known about its molecular mechanism. In this study, we found that a novel goose astrovirus (GAstV), GAstV-GD, and its open reading frame 2 (ORF2) could efficiently activate the innate immune response and induce a high level of OASL in vitro and in vivo. The truncation assay for ORF2 further revealed that the P2 domain of ORF2 contributed to stimulating OASL, whereas the acidic C terminus of ORF2 attenuated such activation. Moreover, the overexpression and knockdown of OASL could efficiently restrict and promote the viral replication of GAstV-GD, respectively. Our data not only give novel insights for elucidating self-limiting infection by astrovirus but also provide virus and host targets for fighting against astroviruses. IMPORTANCE Astroviruses cause gastroenteritis and encephalitis in human, and nephritis, hepatitis, and gout disease in poultry. However, the host immune response activated by astrovirus is mostly unknown. Here, we found that a novel goose astrovirus, GAstV-GD, and its ORF2 protein could efficiently induce a high level of OASL in vitro and in vivo, which could feed back to restrict the replication of GAstV-GD, revealing novel innate molecules triggered by astroviruses and highlighting that the ORF2 of GAstV-GD and OASL can be potential antiviral targets for astroviruses.

scholarly journals Isolation and Identification of Some Probiotic Bacteria and Their Potential Role in Improving Immune Response and Resistance of Nile Tilapia (Oreochromis niloticus) in Comparison with a Commercial Product

2020 ◽  
Vol 2020 ◽  
pp. 1-9
Author(s):  
Mosleh M. Abomughaid
Keyword(s):  
Immune Response ◽  
Oreochromis Niloticus ◽  
Nile Tilapia ◽  
Management Tool ◽  
Phagocytic Index ◽  
Control Group ◽  
Second Phase ◽  
Feeding Experiment ◽  
Isolation And Identification

This work aimed to retrieve a field isolate of probiotic from Nile tilapia (Oreochromis niloticus) and compare the obtained results with a commercial probiotic product through experimental studies. The study was conducted on 250 Nile tilapia. Ten fish were used to isolate the probiotic strain. Two isolates showed an in vitro inhibitory effect against pathogenic A. hydrophila. The isolate with the largest zone was identified by PCR. Sixty fish were used to test the safety of a potential probiotic. One hundred and eighty fish were used in a two-month feeding experiment. Fish were divided into 3 groups, group (1): the control, group (2): fed on potential probiotics, and group (3): fed on commercial probiotic (Organic Green™). The effects of tested products on the immune response were recorded in all groups. After one and two months of feeding experiment, blood and nonspecific immune parameters were evaluated. Disease resistance against Aeromonas hydrophila was evaluated through challenge experiment. The histopathology of the treated groups was fully recorded in comparison with the control group. The potential probiotic based on the in vitro antimicrobial activity test was identified as P. putida using routine and gel electrophoresis and 16S rRNA sequencing. During the first and the second month of experiment, there was a highly significant increase in the survival percent of the experimental fish in both treated groups with probiotics. In the first phase of the experiment, a significant increase in the haematocrit values and NBT, lysozyme activity, and phagocytic activity was seen in all treated groups in comparison with the control. The increase in the TLC was significant in the group fed with P. putida in comparison with the control group. In the second phase, a nonsignificant increase in the hematocrit values and significant increases in the NBT and phagocytic index were seen in P. putida and organic green groups in comparison with the control group. The TLC and DLC revealed nonsignificant changes in the treated groups in comparison with the control. The RLP in the groups treated with P. putida was higher than that in those treated with organic green. Although probiotics are an important management tool in aquaculture, it should be subjected to scientific laboratory tests and field measurements.

scholarly journals Efficacy and safety of boric acid as a preventive treatment against Saprolegnia infection in Nile tilapia (Oreochromis niloticus)

2019 ◽  
Vol 9 (1) ◽  
Author(s):  
Shimaa E. Ali ◽  
Amr A. A. Gamil ◽  
Ida Skaar ◽  
Øystein Evensen ◽  
Harrison Charo-Karisa
Keyword(s):  
Boric Acid ◽  
Oreochromis Niloticus ◽  
Nile Tilapia ◽  
Negative Impact ◽  
Preventive Treatment ◽  
Economic Losses ◽  
Continuous Exposure ◽  
Prophylactic Measure

AbstractSaprolegniosis is a worldwide fungal-like infection affecting freshwater fishes and their eggs. Reports show high mortalities and subsequent economic losses annually from Saprolegnia infections. Most therapeutants against Saprolegnia spp. infections are inefficient and some have negative impact on the environment. In this study, we have investigated the ability of boric acid (BA) to prevent Saprolegnia infection in Nile tilapia (Oreochromis niloticus). BA inhibited radial growth of Saprolegnia hyphae in vitro. Complete in vitro growth inhibition was found at a concentration of ≥0.6 g/L. Inhibitory effects were also observed in vivo when Nile tilapia were experimentally challenged with Saprolegnia spores and followed over 10 days post challenge and under continuous exposure to different BA concentrations. No signs of saprolegniosis were observed in fish treated with BA at concentrations of 0.4 g/L and above. Comet assay revealed that BA has low toxicity in tilapia continuously exposed to concentrations of 0.2–0.6 g/L for 96 h. Additionally, no significant histomorphological changes were observed in BA-treated fish compared to non-treated controls. Alanine Aminotransferase (ALT) and Aspartate Aminotransferase (AST) enzyme levels indicated reduction in systemic tissue damage associated with Saprolegnia infection. This study demonstrates the potential of BA as a prophylactic measure against Saprolegnia infection in tilapia, and we recommend additional studies on environmental impact.

scholarly journals Shrimp lectin (Md-Lec) conjugated copper sulfide nanoparticles enhance the elimination of aquatic pathogens in infected Nile tilapia (Oreochromis niloticus)

RSC Advances ◽  
2020 ◽  
Vol 10 (72) ◽  
pp. 44216-44224
Author(s):  
Abdul Salam Rubeena ◽  
Sreeja Lakshmi ◽  
Digi George ◽  
Siva Bala Subramaniyan ◽  
Anbazhagan Veerappan ◽  
...  
Keyword(s):  
Antibacterial Activity ◽  
Oreochromis Niloticus ◽  
Copper Sulfide ◽  
Nile Tilapia ◽  
Nile Tilapia Oreochromis Niloticus ◽  
Aquatic Pathogens

Synthesis of Md-Lec-pCuSNPs and its enhanced in vitro and in vivo antibacterial activity.

scholarly journals Transcriptional knockout of steroidogenic factor 1 in vivo in Oreochromis niloticus increased weight and suppressed gonad development using antisense RNA

2021 ◽  
Author(s):  
Zhe Cao ◽  
Jun Qiang ◽  
Jun Zhu ◽  
Hong Li ◽  
Yi Tao ◽  
...  
Keyword(s):  
Oreochromis Niloticus ◽  
Antisense Rna ◽  
Nile Tilapia ◽  
Gonad Development ◽  
External Genitalia ◽  
Cloning And Expression ◽  
Steroidogenic Factor 1 ◽  
And Function

Abstract Steroidogenic factor 1 (sf1) is an important regulator of gonad development and function in mammals. However, study of sf1 in fish is limited to cloning and expression and in vitro experiments. Using antisense RNA we knockout transcription of the sf1 gene in Nile tilapia Oreochromis niloticus, and obtain experimental fish in vivo. We demonstrate that antisense RNA can silence sf1 transcription and protein expression, and report suppression of sf1 transcription to affect gonad development and external genitalia formation in Nile tilapia. We also report disfunction of retinal metabolism and fatty acid metabolism to be important causes of weight gain and gonad abnormality with sf1 suppression. The feasibility of using antisense RNA for gene editing in fish is verified, and a new way of studying gene function and performing biological breeding is presented.

scholarly journals Blocking of progestin action disrupts spermatogenesis in Nile tilapia (Oreochromis niloticus)

2014 ◽  
Vol 53 (1) ◽  
pp. 57-70 ◽  
Author(s):  
Gang Liu ◽  
Feng Luo ◽  
Qiang Song ◽  
Limin Wu ◽  
Yongxiu Qiu ◽  
...  
Keyword(s):  
Sertoli Cells ◽  
Oreochromis Niloticus ◽  
Nile Tilapia ◽  
Phylogenetic Analyses ◽  
Pcr Analysis ◽  
Steroidogenic Enzymes ◽  
Spermatogonial Cell

In vitrostudies have indicated that the maturation-inducing hormone 17α,20β-dihydroxy-4-pregnen-3-one (17α,20β-DP, DHP), probably through nuclear progestin receptor (Pgr), might be involved in the proliferation of spermatogonial cells and the initiation of meiosis in several fish species. However, furtherin vivoevidence is required to elucidate the role of DHP in spermatogenesis during sexual differentiation in teleosts. In this study, we clonedpgrand analyzed its expression in Nile tilapia (Oreochromis niloticus) and treated XY fish with RU486 (a synthetic Pgr antagonist) from 5 days after hatching (dah) to determine the role of DHP in spermatogenesis. Sequence and phylogenetic analyses revealed that the Pgr identified in tilapia is a genuine Pgr. Pgr was found to be expressed in the Sertoli cells surrounding spermatogonia and spermatids in the testis of tilapia. Real-time PCR analysis revealed that the expression ofpgrin the testis was significantly upregulated from 10 dah, further increased at 50 dah, and persisted until adulthood in fish. In the testis of RU486-treated fish, the transcript levels of germ cell markers and a meiotic marker were substantially reduced. However, the expression of markers in Sertoli cells remained unchanged. Moreover, the production of 11-ketotestosterone and the expression of genes encoding various steroidogenic enzymes were also not altered. In contrast, the expression ofcyp17a2, encoding one of the critical steroidogenic enzymes involved in DHP biosynthesis, declined significantly, possibly indicating the inhibition of DHP production by RU486. RU486 treatment given for 2 months did not affect spermatogenesis; however, treatment given for more than 3 months resulted in a decrease in spermatogonial cell numbers and depletion of later-phase spermatogenic cells. Simultaneous excessive DHP supplementation restored spermatogenesis in RU486-treated XY fish. Taken together, our data further indicated that DHP, possibly through Pgr, might be essential for spermatogonial cell proliferation and spermatogenesis in fish.

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