79 research outputs found

    Selectable marker independent transformation of recalcitrant maize inbred B73 and sorghum P898012 mediated by morphogenic regulators \u3ci\u3eBABY BOOM\u3c/i\u3e and \u3ci\u3eWUSCHEL2\u3c/i\u3e

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    The use of morphogenic regulators to overcome barriers in plant transformation is a revolutionary breakthrough for basic plant science and crop applications. Current standard plant transformation systems are bottlenecks for genetic, genomic, and crop improvement studies. We investigated the differential use of co-expression of maize transcription factors BABY BOOM and WUSCHEL2 coupled with a desiccation inducible CRE/lox excision system to enable regeneration of stable transgenic recalcitrant maize inbred B73 and sorghum P898012 without a chemical selectable marker. The PHP78891 expression cassette contains CRE driven by the drought inducible maize RAB17M promoter with lox P sites which bracket the CRE, WUS, and BBM genes. A constitutive maize UBIM promoter directs a ZsGreen GFP expression cassette as a reporter outside of the excision sites and provides transient, transgenic, and developmental analysis. This was coupled with evidence for molecular integration and analysis of stable integration and desiccation inducible CRE-mediated excision. Agrobacterium-mediated transgenic introduction of this vector showed transient expression of GFP and induced somatic embryogenesis in maize B73 and sorghum P898012 explants. Subjection to desiccation stress in tissue culture enabled the excision of CRE, WUS, and BBM, leaving the UBIM::GFP cassette and allowing subsequent plant regeneration and GFP expression analysis. Stable GFP expression was observed in the early and late somatic embryos, young shoots, vegetative plant organs, and pollen. Transgene integration and expression of GFP positive T0 plants were also analyzed using PCR and Southern blots. Progeny segregation analysis of primary events confirmed correlation between functional GFP expression and presence of the GFP transgene in T1 plants generated from self pollinations, indicating good transgene inheritance. This study confirms and extends the use of morphogenic regulators to overcome transformation barriers

    Investigations on Rare Earth Elements in Sediments from South Vellar Estuary along Bay of Bengal and Palk Strait, Tamil Nadu, India

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    The rare earth elements (REEs) in the sediments of the South Vellar estuary on the eastern coast of India were measured using thermal ionization mass spectrometry (TIMS). Lanthanides (La-Lu) and a number of other elements (Cr, Ni, Zn, Pb, Ag, Co, Cd, and V) were studied in bed sediment samples. The estuary’s total REE content (REE) ranges from 73.30 to 360.50 g/g. Continental weathering has a substantial impact on the distribution of REEs. Using factor analysis on the elemental data, two important groups of elements were identified: (a) LREEs, HREEs, Pb, Ag, and Cd, revealing an association with river detritals; and (b) Co, Ni, Zn, Cr, and V, indicating complex estuary processes. Because of the silicate weathering of crustal materials and the resultant increase in LREEs in detritals, LREEs are more enriched than HREEs. We get to the conclusion that 30% of HREE flux and 70% of LREE flux to the Bay of Bengal are provided by the estuarine system

    A Novel Peptide ELISA for Universal Detection of Antibodies to Human H5N1 Influenza Viruses

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    BACKGROUND: Active serologic surveillance of H5N1 highly pathogenic avian influenza (HPAI) virus in humans and poultry is critical to control this disease. However, the need for a robust, sensitive and specific serologic test for the rapid detection of antibodies to H5N1 viruses has not been met. METHODOLOGY/PRINCIPAL FINDINGS: Previously, we reported a universal epitope (CNTKCQTP) in H5 hemagglutinin (HA) that is 100% conserved in H5N1 human isolates and 96.9% in avian isolates. Here, we describe a peptide ELISA to detect antibodies to H5N1 virus by using synthetic peptide that comprises the amino acid sequence of this highly conserved and antigenic epitope as the capture antigen. The sensitivity and specificity of the peptide ELISA were evaluated using experimental chicken antisera to H5N1 viruses from divergent clades and other subtype influenza viruses, as well as human serum samples from patients infected with H5N1 or seasonal influenza viruses. The peptide ELISA results were compared with hemagglutinin inhibition (HI), and immunofluorescence assay and immunodot blot that utilize recombinant HA1 as the capture antigen. The peptide ELISA detected antibodies to H5N1 in immunized animals or convalescent human sera whereas some degree of cross-reactivity was observed in HI, immunofluorescence assay and immunodot blot. Antibodies to other influenza subtypes tested negative in the peptide-ELISA. CONCLUSION/SIGNIFICANCE: The peptide-ELISA based on the highly conserved and antigenic H5 epitope (CNTKCQTP) provides sensitive and highly specific detection of antibodies to H5N1 influenza viruses. This study highlighted the use of synthetic peptide as a capture antigen in rapid detection of antibodies to H5N1 in human and animal sera that is robust, simple and cost effective and is particularly beneficial for developing countries and rural areas

    Iron(III) complexes of certain meridionally coordinating tridentate ligands as models for non-heme iron enzymes: the role of carboxylate coordination

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    The iron(III) complexes [Fe(pda)Cl(H2O)2] (1), [Fe(tpy)Cl3] (2), and [Fe(bbp)Cl3] (3), where H2pda is pyridine-2,6-dicarboxylic acid, tpy is 2,2':6,2"-terpyridine and bbp is 2,6-bis(benzimidazolyl)pyridine, have been isolated and studied as functional models for the intradiol-cleaving catechol dioxygenase enzymes. Mixed ligand complexes of H2pda with the bidentate ligands 2,2'-bipyridine (bpy) and 1,10-phenanthroline (phen) have been also prepared and studied. All the complexes have been characterized using absorption spectral and electrochemical methods. The spectral changes in the catecholate adducts of the complexes generated in situ have been investigated. Upon interacting the complexes with catecholate anions a low energy catecholate to iron(III) charge transfer band appears, which is similar to that observed for enzyme-substrate complexes. All the complexes catalyze the oxidative intradiol cleavage of 3,5-di-tert-butylcatechol (H2dbc) in the presence of dioxygen. Interestingly, on replacing the pyridyl groups in 2 and the bulky benzimidazole groups in 3 by the carboxylate groups, the yields of the intradiol cleavage products of dioxygenation increases, 1 (50%) > 2 (20%) > 3 (10%). The higher intradiol yield for 1 has been ascribed to the meridional coordination of two carboxylate groups of pda2-. In contrast to the trend in the intradiol cleavage yields, a tremendous decrease in the rate (200 times) is observed on replacing the two pyridyl moieties in 2 by two carboxylates as in 1 and a significant decrease in rate is observed on replacing the pyridyl moieties in 2 by strongly σ -donating benzimidazole moieties as in 3. This is in conformity with the decrease in Lewis acidities of the iron(III) centers

    Vaccines against Major Poultry Viral Diseases: Strategies to Improve the Breadth and Protective Efficacy

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    The poultry industry is the largest source of meat and eggs for human consumption worldwide. However, viral outbreaks in farmed stock are a common occurrence and a major source of concern for the industry. Mortality and morbidity resulting from an outbreak can cause significant economic losses with subsequent detrimental impacts on the global food supply chain. Mass vaccination is one of the main strategies for controlling and preventing viral infection in poultry. The development of broadly protective vaccines against avian viral diseases will alleviate selection pressure on field virus strains and simplify vaccination regimens for commercial farms with overall savings in husbandry costs. With the increasing number of emerging and re-emerging viral infectious diseases in the poultry industry, there is an urgent need to understand the strategies for broadening the protective efficacy of the vaccines against distinct viral strains. The current review provides an overview of viral vaccines and vaccination regimens available for common avian viral infections, and strategies for developing safer and more efficacious viral vaccines for poultry

    Additional file 1: Figure S1. of Immunohistochemical insights into Saffold virus infection of the brain of juvenile AG129 mice

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    High magnification micrograph of Immunohistochemical stain showing co-localisation of SAFV VP1 with NeuN or GFAP. Brain sections tissue of 6dpi SAFV infected 2 week-old AG129 mice were stain with anti-SAFV VP1 and anti-NeuN or anti-GFAP. Stained SAFV infected or uninfected mice brain sections were viewed and taken with a confocal fluorescence microscope. SAFV VP1 is labelled in red, NeuN or GFAP is labelled in green, and DAPI is labelled in blue. (JPG 297 kb

    Gastrointestinal Delivery of Baculovirus Displaying Influenza Virus Hemagglutinin Protects Mice against Heterologous H5N1 Infection▿

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    The recent outbreaks of influenza A H5N1 virus in birds and humans have necessitated the development of potent H5N1 vaccines. In this study, we evaluated the protective potential of an immediate-early promoter-based baculovirus displaying hemagglutinin (BacHA) against highly pathogenic avian influenza (HPAI) H5N1 virus infection in a mouse model. Gastrointestinal delivery of BacHA significantly enhanced the systemic immune response in terms of HA-specific serum IgG and hemagglutination inhibition (HI) titers. In addition, BacHA vaccine was able to significantly enhance the mucosal IgA level. The inclusion of recombinant cholera toxin B subunit as a mucosal adjuvant along with BacHA vaccine did not influence either the systemic or mucosal immunity. Interestingly, an inactivated form of BacHA was able to induce only a negligible level of immune responses compared to its live counterpart. Microneutralization assay also indicated that live BacHA vaccine was able to induce strong cross-clade neutralization against heterologous H5N1 strains (clade 1.0, clade 2.1, and clade 8.0) compared to the inactivated BacHA. Viral challenge studies showed that live BacHA was able to provide 100% protection against 5 50% mouse lethal doses (MLD50) of homologous (clade 2.1) and heterologous (clade 1) H5N1. Moreover, histopathological examinations revealed that mice vaccinated with live BacHA had only minimal bronchitis in lungs and regained their body weight more rapidly postchallenge. Furthermore, immunohistochemistry results demonstrated that the live BacHA was able to transduce and express HA in the intestinal epithelial cells in vitro and in vivo. We have demonstrated that recombinant baculovirus with a white spot syndrome virus (WSSV) immediate-early promoter 1 (ie1) acted as a vector as well as a protein vaccine and will enable the rapid production of prepandemic and pandemic vaccines without any biosafety concerns
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