Re-engineering of bicistronic plasmid pGPD/IFN to construct fusion gene co-expressing Glyceraldehyde 3-phosphate dehydrogenase gene (GAPDH) of Edwardsiella tarda and Interferon-gamma (IFN-γ) gene of Labeo rohita (Hamilton) and its in vitro functional analysis

Edwardsiella septicemia disease in the cultured Indian major carps is caused by the fish pathogen Edwardsiella tarda and it is preventable by DNA vaccination. Here, we tried to develop a bicistronic DNA vaccine pGPD/IFN expressing the Glyceraldehyde 3-phosphate dehydrogenase (GAPDH) gene of Edwardsiella tarda and Interferon-gamma (IFN-γ) gene of Labeo rohita. The vaccine showed high protective efficiency in our previous studies; however as a limitation of bicistronic construct the expression of gene cloned in second frame (B) is poor. To overcome this limitation we re-engineered the construct and designed a fusion gene co-expressing the GAPDH and IFN-γ genes as one frame with an aim to get the optimum expression of both the genes. For this purpose, a fusion insert comprising GAPDH and IFN-γ coding sequences was cloned in to pcDNA3.1(+) plasmid vector. The fusion genes' in vitro expression was confirmed in the striped snakehead fish cell line (SSN-1). Successful expression of the re-engineered fusion gene DNA vaccine in the cell line was achieved at 48h post-transfection, which was confirmed by amplifying the expression transcripts of GAPDH and IFN-γ genes. Thus, the study concludes that the re-engineered fusion vaccine pcGPD/IFN (pcDNA3.1(+) plasmid having fusion GPD/IFN) is functional and can be effectively utilized to vaccinate rohu (Labeo rohita) as it contains the species-specific immune gene (IFN-γ) as an adjuvant

Population genetics of Indian giant river-catfish, Sperata seenghala (Sykes, 1839) using microsatellite markers

The giant river-catfish Sperata seenghala is one of the commercially important freshwater catfishes of India with wide distribution in all major rivers and reservoirs. This fish has huge demand in domestic market due to high nutritional value and low number of intramuscular bones. Conversely, the culture practices for this fish have not yet been standardized and capture fisheries is the only source to meet the demand. This may lead to over exploitation of resources and subsequent population reduction. Knowledge on genetic structure of populations is prerequisite to formulate sustainable management and conservation measures. In the present study, 15 microsatellites were used to characterize population genetics of S. seenghala collected from river Brahmaputra, Ganga, Godavari, Mahanadi and Narmada. Locus-wise, the number of alleles varied from 8 to 19 with an average of 12 alleles per locus. The mean observed and expected heterozygosity values varied from 0.622 to 0.699 and 0.733 to 0.774, respectively. Several loci have shown deviation from Hardy–Weinberg equilibrium and no significant linkage disequilibrium between pairs of loci was detected. Pair-wise FST values between populations ranged from 0.135 (Brahmaputra–Ganga) to 0.173 (Brahmaputra–Narmada) and confirmed the moderate to high genetic differentiation among the populations. AMOVA, Structure and Principal Co-ordinate analyses showed significant genetic differentiation among the sampled populations of S. seenghala. A total of 65 private alleles were recorded across populations. This study confirmed the distinctiveness of each population of S. seenghala from five major rivers of India. These populations could be treated as distinct management units (MUs) for assessment and management purpose

A longitudinal study to examine the influence of farming practices and environmental factors on pathogen prevalence using structural equation modeling

The contamination of fresh produce with foodborne pathogens has been an on-going concern with outbreaks linked to these commodities. Evaluation of farm practices, such as use of manure, irrigation water source, and other factors that could influence pathogen prevalence in the farming environment could lead to improved mitigation strategies to reduce the potential for contamination events. Soil, water, manure, and compost were sampled from farms in Ohio and Georgia to identify the prevalence of Salmonella, Listeria monocytogenes (Lm), Campylobacter, and Shiga-toxin-producing Escherichia coli (STEC), as well as Arcobacter, an emerging human pathogen. This study investigated agricultural practices to determine which influenced pathogen prevalence, i.e., the percent positive samples. These efforts identified a low prevalence of Salmonella, STEC, and Campylobacter in soil and water (< 10%), preventing statistical modeling of these pathogens. However, Lm and Arcobacter were found in soil (13 and 7%, respectively), manure (49 and 32%, respectively), and water samples (18 and 39%, respectively) at a comparatively higher prevalence, suggesting different dynamics are involved in their survival in the farm environment. Lm and Arcobacter prevalence data, soil chemical characteristics, as well as farm practices and weather, were analyzed using structural equation modeling to identify which factors play a role, directly or indirectly, on the prevalence of these pathogens. These analyses identified an association between pathogen prevalence and weather, as well as biological soil amendments of animal origin. Increasing air temperature increased Arcobacter and decreased Lm. Lm prevalence was found to be inversely correlated with the use of surface water for irrigation, despite a high Lm prevalence in surface water suggesting other factors may play a role. Furthermore, Lm prevalence increased when the microbiome’s Simpson’s Diversity Index decreased, which occurred as soil fertility increased, leading to an indirect positive effect for soil fertility on Lm prevalence. These results suggest that pathogen, environment, and farm management practices, in addition to produce commodities, all need to be considered when developing mitigation strategies. The prevalence of Arcobacter and Lm versus the other pathogens suggests that multiple mitigation strategies may need to be employed to control these pathogens

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Not AvailableIn the present study, full-length CYP1AcDNA from Catla catla (Catla) has been identified,and its real-time quantitative reverse transcription PCR(qRT-PCR) expression has been evaluated in differenttissues, developmental stages (0, 3, 6, 12 and 24 h and 5,7 and 9 days post-fertilization) and copper sulphate andbenzo(a)pyrene (BaP)-treated 5-day post-fertilization(dpf) larvae (6 to 6.5 mm). Various structural, compar-ative and phylogenetic analyses of the deduced aminoacid sequence revealed that the identified gene of Catlabelongs to the CYP1A1 subfamily. Among differenttissues of Catla, the highest CYP1A expression wasobserved in the kidney followed by the liver, muscle,gill, intestine and brain. CYP1A mRNA expression wasdetected during all the larval developmental stages,including the unfertilized egg with the highest expres-sion on 9 dpf. BaP (3.5 ppb) and copper sulphate (sub-lethal dose 0.516 ppm) challenge test for 96 h to Catlalarvae revealed the highest CYP1A1 expression at 48 hpost-challenge. CYP1A1 transcript also showed aconcentration-dependent increase in expression follow-ing exposure at 1.75 and 3.5 ppb of BaP for 48 h. Itsexpression profiling indicates that it is functional at earlydevelopmental stages. It can also be used to develop aspecific biomarker tool for monitoring environmental pollution.Not Availabl

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Not AvailableIn the present study, full-length CYP1A cDNA from Catla catla (Catla) has been identified, and its real-time quantitative reverse transcription PCR (qRT-PCR) expression has been evaluated in different tissues, developmental stages (0, 3, 6, 12 and 24 h and 5, 7 and 9 days post-fertilization) and copper sulphate and benzo(a)pyrene (BaP)-treated 5-day post-fertilization (dpf) larvae (6 to 6.5 mm). Various structural, comparative and phylogenetic analyses of the deduced amino acid sequence revealed that the identified gene of Catla belongs to the CYP1A1 subfamily. Among different tissues of Catla, the highest CYP1A expression was observed in the kidney followed by the liver, muscle, gill, intestine and brain. CYP1A mRNA expression was detected during all the larval developmental stages, including the unfertilized egg with the highest expression on 9 dpf. BaP (3.5 ppb) and copper sulphate (sublethal dose 0.516 ppm) challenge test for 96 h to CatlaNot Availabl

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Not AvailableEdwardsiella tarda is a versatile pathogen that could survive in different environmental conditions and infect economically important fish species. The whole cell antigenic proteins were extracted from E. tarda and assessed via Western blot using anti E. trada rohu and anti E. trada rabbit serum. Two strong reacted proteins with antibodies were recovered viz 61 kDa and 47 kDa from SDS PAGE gels to evaluate their vaccine potential in rohu fish. Fish were vaccinated 10 µg of antigenic proteins intraperitoneally as immunogens with Freund’s incomplete adjuvant (FIA). The boosters were given on the 10th day of immunization with PBS. The blood was drawn from vena caudalis at every 7th day for hematological and immunological studies. Fish were challenged on 35th day with 1× 106 cfu E. tarda field isolate ET-1.Not Availabl

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Not AvailableThe present study was carried out to assess the genetic diversity of three different species of Sargassum viz., S. swartzii, S. tenerrimum and S. plagiophyllum collected from Okhaport, Malwan and Veraval respectively, along the north-west coast of India, using Inter Simple Sequence Repeats (ISSR) primer. A total of five ISSR primers, namely ISSR-807, ISSR-811, ISSR-840, ISSR-855 and ISSR-859 were used for the genetic diversity studies. A total of thirty numbers of each species were taken for the analysis. Software POPGENE version 1.32 was used to estimate the percentage of polymorphic loci (P), Nei’s gene diversity (h) and genetic identity and genetic distance (D). The percentage of polymorphic loci over all the primers was 12.5% in S. swartzii, 20% in S. tenerrimum and 40% in S. plagiophyllum. The genetic diversity was comparatively less in S. swartzii (0.06) and S. tenerrimum (0.07), whereas it was 0.21 in S. plagiophyllum. Nei’s genetic distance (D) was higher in all the species as expected among species of same genus.Not Availabl

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Not AvailableImmunoglobulin M (IgM) is the major isotype among teleost immunoglobulins. The present study was aimed to explore IgM heavy chain gene and its expression profile in rohu. Fulllength IgM heavy chain cDNA of rohu consisted of 1994 bp encoding a polypeptide of 576 amino acid residues including a leader peptide, variable (VH) and constant (CH1–CH2–CH3–CH4) domains confirming the secretory form of IgM. The sequence carries conserved residues such as cysteine, tryptophan and amino acid motifs like ‘YYCAR’ and ‘FDYWGKGT–VTV–S’. The predicted 3 D model confirmed various domains of rohu IgM heavy chain. Phylogenetic tree analysis revealed that IgM heavy chain gene of rohu shared the same cluster with that of other cyprinid fishes. Tissue distribution analysis showed the predominant level of IgM heavy chain gene expression in kidney, spleen and intestine. IgM heavy chain gene expression in rohu kidney was found to be up-regulated and reached a maximum at 7 days post-challenge with Aeromonas hydrophila. These findings demonstrate the first report of full-length secretory IgM heavy chain gene in rohu. Besides, IgM heavy chain gene was highly expressed in major lymphoid tissues and bacterial challenge influenced its expression which further confirmed its role in the adaptive humoral immune response.Not Availabl

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