Comparative Analysis of the Genetic Diversity of Chilean Cultivated Potato Based on a Molecular Study of Authentic Herbarium Specimens and Present-Day Gene Bank Accessions.

At the end of the 1920s, Vavilov organized several potato-collecting missions in South and Central America. Vavilov and his colleagues, Juzepczuk and Bukasov, participated in these expeditions and worked on gathered material, designated two centers of potato varietal riches and diversity-the Peru-Bolivia high-mountain center and the southern coast of Chile. The WIR Herbarium holds authentic specimens of many taxa described by Russian taxonomists. Here, a set of 20 plastid DNA-specific markers was applied for 49 authentic herbarium specimens of Solanum tuberosum L. from the WIR Herbarium to analyze the genetic diversity of the landrace population collected by Juzepczuk in 1928 in southern-central Chile. Two plastid DNA types, T and A, and two chlorotypes were identified in herbarium specimens, with a clear predominance (96%) of chlorotype cpT_III. In addition, we analyzed 46 living Chilean accessions from the VIR field potato gene bank that were collected after the appearance of Phytophthora infestans in Chile. These living accessions were differentiated into four chlorotypes. Finding a D-type cytoplasm in living Chilean accessions that possess two new chlorotypes indicates a replacement of native cultivars and introgression from the wild Mexican species S. demissum that was actively used in breeding as a source of race-specific resistance to late blight.

An Outbreak of a Respiratory Disorder at a Russian Swine Farm Associated with the Co-Circulation of PRRSV1 and PRRSV2.

We conducted a cross-sectional study to identify the major respiratory pathogen responsible for an outbreak of respiratory disease at a swine farm in West Siberia in 2019. We discovered that the peak of morbidity and mortality coincided with a high level of porcine reproductive and respiratory syndrome virus (PRRSV) 1 and 2-related viremia. Based on longer PRRSV2 viremia, the dominant role of PRRSV2 over PRRSV1 in the outbreak was assumed. Phylogenetic analysis revealed that the PRRSV1 strain belonged to sub-genotype 2-one of the predominant groups of genotype 1 PRRSVs in Russia. A partial open reading frame 7 sequence of the PRRSV2 isolate demonstrated a high identity with modified live vaccine-related strains from Denmark (93%) and wild-type VR2332 (92%). We identified the first instance of PRRSV1/PRRSV2 mixed infection in Russia. This finding indicates that further field investigations are needed to access PRRSV2 epidemiology in eastern Europe.

Development and characterization of two GP-specific monoclonal antibodies, which synergistically protect non-human primates against Ebola lethal infection.

Ebola fever is an acute highly contagious viral disease characterized by severe course, high mortality and development of hemorrhagic syndrome (tendency to skin hemorrhage and bleeding of mucous membranes). The mortality rate of the disease 60-90%. Nowadays, there are no licensed specific therapeutic agents for Ebola in the world. Monoclonal antibodies (MAbs) having viral neutralizing activity with high specificity to the GP protein of the Ebola virus are considered as candidate highly effective antiviral drugs. In our study, for the first time a panel of mouse monoclonal antibodies specifically binding to EBOV GP protein was obtained using recombinant human adenovirus 5 serotype, expressing GP protein (Ad5-GP). The virus-neutralizing capacities of antibodies were evaluated on the Ebola virus cell infection model, as well as recombinant vesicular stomatitis virus pseudotyped by GP Ebola virus protein (rVSV-GP) cell infection model. Based on the results of virus neutralization, two most promising clones were selected, the specific and protective capacities of which were determined. The study of the protection of selected individual antibody clones, as well as their combinations on the model of lethal infection of rhesus macaques with Ebola virus showed that intravenous administration of a mixture of antibodies in the amount of 50 mg/kg 24 h after infection leads to the survival of 100% of the animals, while individual clones of antibodies possess partial protection (0-30%). The results of the study suggest the important role of antibodies in controlling replication of the Ebola virus in vivo and show the possibility of using a mixture of antibodies specific to the GP to protect against lethal infection with the Ebola virus in the post-infected mode of administration.

Structural Organization of 6B9 Molecule, a Monoclonal Antibody Against Lycopene.

Full cDNA and corresponding amino acid (AA) sequences of 6B9 monoclonal antibody (mAb) against lycopene was obtained using Step-Out RACE technology. Variable (V) and constant (C) regions were identified. The light chain of 6B9 contained 238 AA IgM with the highest level of identity (0.93) to both the anti-VEGF receptor antibody and anti-collagen type II FAb CIIC1. The heavy chain was composed of 634 AA with a high identity (0.9) to the Ig mu chain C region. Potential posttranslational modification regions in both chains were identified alongside with disulfide bond sites. The obtained information can be used for making chimeric constructs containing 6B9 mAb (or its fragments) and lycopene, a powerful carotenoid with antioxidant as well as antiproliferating properties, which can be implemented in the treatment of an aggressive form of prostate cancer and possibly other malignancies.

Generation and Application of Monoclonal Antibody Against Lycopene.

A monoclonal antibody (Mab) against lycopene was developed from hybridoma clones obtained from BALB/c mice immunized with trans-isomer of lycopene (t-lycopene, t-LC) conjugated with colloidal gold particles. An alternating immunization schedule which included injection of both formulations of immunogen (without and with Freund's adjuvant) was most effective in the elucidation of a measurable immune response to the t-Lycopene conjugate. Selected hybridoma clones were able to produce an Mab positive in competition assay. In particular, preincubation of 6B9 Mabs with t-LC abolished the ability of 6B9 Mabs to bind LC in the competition assay. Mabs produced by other clones (4F10, 4A3, and 3B12) worked similarly. Analysis of antigen specificity showed that 6B9 Mab raised against t-LC did not recognize other carotenoids such as lutein and carotene. Mab 6B9 was shown to recognize lycopene on a glass surface and in the settings of indirect immunofluorescence experiments performed in cultured hepatocytes and alveolar macrophages incubated with and without lycopene, as well as in sebum and corneocyte specimens from the skin of volunteers supplemented with nutraceutical formulation of lycopene. Newly generated Mabs against lycopene may provide a valuable tool for different analytical assays of lycopene content in various biological, agricultural, and food products.

Removal of polycyclic aromatic hydrocarbons in soil spiked with model mixtures of petroleum hydrocarbons and heterocycles using biosurfactants from Rhodococcus ruber IEGM 231.

Removal of polycyclic aromatic hydrocarbons (PAHs) in soil using biosurfactants (BS) produced by Rhodococcus ruber IEGM 231 was studied in soil columns spiked with model mixtures of major petroleum constituents. A crystalline mixture of single PAHs (0.63g/kg), a crystalline mixture of PAHs (0.63g/kg) and polycyclic aromatic sulfur heterocycles (PASHs), and an artificially synthesized non-aqueous phase liquid (NAPL) containing PAHs (3.00g/kg) dissolved in alkanes C10-C19 were used for spiking. Percentage of PAH removal with BS varied from 16 to 69%. Washing activities of BS were 2.5 times greater than those of synthetic surfactant Tween 60 in NAPL-spiked soil and similar to Tween 60 in crystalline-spiked soil. At the same time, amounts of removed PAHs were equal and consisted of 0.3-0.5g/kg dry soil regardless the chemical pattern of a model mixture of petroleum hydrocarbons and heterocycles used for spiking. UV spectra for soil before and after BS treatment were obtained and their applicability for differentiated analysis of PAH and PASH concentration changes in remediated soil was shown. The ratios A254nm/A288nm revealed that BS increased biotreatability of PAH-contaminated soils.