Generation and diversification of recombinant monoclonal antibodies

Antibodies are indispensable tools used for a large number of applications in both foundational and translational bioscience research; however, there are drawbacks to using traditional antibodies generated in animals. These include a lack of standardization leading to problems with reproducibility, high costs of antibodies purchased from commercial sources, and ethical concerns regarding the large number of animals used to generate antibodies. To address these issues, we have developed practical methodologies and tools for generating low-cost, high-yield preparations of recombinant monoclonal antibodies and antibody fragments directed to protein epitopes from primary sequences. We describe these methods here, as well as approaches to diversify monoclonal antibodies, including customization of antibody species specificity, generation of genetically encoded small antibody fragments, and conversion of single chain antibody fragments (e.g. scFv) into full-length, bivalent antibodies. This study focuses on antibodies directed to epitopes important for mitosis and kinetochore function; however, the methods and reagents described here are applicable to antibodies and antibody fragments for use in any field.

Host Range, Biology, and Species Specificity of Seven-Segmented Influenza Viruses—A Comparative Review on Influenza C and D

Other than genome structure, influenza C (ICV), and D (IDV) viruses with seven-segmented genomes are biologically different from the eight-segmented influenza A (IAV), and B (IBV) viruses concerning the presence of hemagglutinin–esterase fusion protein, which combines the function of hemagglutinin and neuraminidase responsible for receptor-binding, fusion, and receptor-destroying enzymatic activities, respectively. Whereas ICV with humans as primary hosts emerged nearly 74 years ago, IDV, a distant relative of ICV, was isolated in 2011, with bovines as the primary host. Despite its initial emergence in swine, IDV has turned out to be a transboundary bovine pathogen and a broader host range, similar to influenza A viruses (IAV). The receptor specificities of ICV and IDV determine the host range and the species specificity. The recent findings of the presence of the IDV genome in the human respiratory sample, and high traffic human environments indicate its public health significance. Conversely, the presence of ICV in pigs and cattle also raises the possibility of gene segment interactions/virus reassortment between ICV and IDV where these viruses co-exist. This review is a holistic approach to discuss the ecology of seven-segmented influenza viruses by focusing on what is known so far on the host range, seroepidemiology, biology, receptor, phylodynamics, species specificity, and cross-species transmission of the ICV and IDV.

The barley immune receptor Mla recognizes multiple pathogens and contributes to host range dynamics

Crop losses caused by plant pathogens are a primary threat to stable food production. Stripe rust (Puccinia striiformis) is a fungal pathogen of cereal crops that causes significant, persistent yield loss. Stripe rust exhibits host species specificity, with lineages that have adapted to infect wheat and barley. While wheat stripe rust and barley stripe rust are commonly restricted to their corresponding hosts, the genes underlying this host specificity remain unknown. Here, we show that three resistance genes, Rps6, Rps7, and Rps8, contribute to immunity in barley to wheat stripe rust. Rps7 cosegregates with barley powdery mildew resistance at the Mla locus. Using transgenic complementation of different Mla alleles, we confirm allele-specific recognition of wheat stripe rust by Mla. Our results show that major resistance genes contribute to the host species specificity of wheat stripe rust on barley and that a shared genetic architecture underlies resistance to the adapted pathogen barley powdery mildew and non-adapted pathogen wheat stripe rust.

Differentiation of Dust Holding Capacity of Poplar Crowns

One of the key parameters of comfort and compliance with sanitary standards for cities is dustiness of atmosphere. Plantings of representatives of the poplar genus (Populus L.) become a reliable means of optimizing this parameter. We have studied the effectiveness of using different types of poplars in urban plantings, taking into account the differentiation of crown sections by the ability to deposit dust on the surface of the leaf apparatus. The object of research is 8 species from different sections of the poplar genus, typically found in urban plantings of the Nizhny Novgorod region. We considered the influence of three independently of one another factors on the dispersion of dust holding capacity: species-specificity of poplars (8 gradations); lighting conditions of crown due to its orientation relative to the cardinal directions (4 gradations); height characteristics of the crown tier location (3 gradations). Dust was washed off from 100 leaves of each poplar species with their fixed area. The highest amount of dust in the flushes was observed for silver poplar (257.60±5.05 mg), and the lowest – for black poplar (117.69±3.65 mg) and Pópulus nígra var. itálica (105.69±2.90 mg). Oneway ANOVA confirmed the significance of differences between the species for all parameters of dust holding capacity. Three-way ANOVA showed the influence of leaf surface locations in different parts of the crown on the efficiency of dust deposition by representatives of different species. Species appeared to be the most important in the distribution of dust deposited on the leaf surface of shoots in different parts of the crown; the share of its influence was 37.65±0.51 %. The effect of crown lighting conditions was also well measurable; its share was equal to 20.45±0.28 %. The influence of the crown tier height was noticeably less; its share reached 7.19±0.21 %. The listed factors are little related to each other, and their interaction generated a negligible effect: 6.67±4.54 %, Fh2 = 1.47, significance is reliable at 5 % level (F05 = 1.41) and unreliable at 1 % level (F01 = 1.61). For citation: Besschetnova N.N., Besschetnov P.V. Differentiation of Dust Holding Capacity of Poplar Crowns. Lesnoy Zhurnal [Russian Forestry Journal], 2021, no. 5, pp. 48–64. DOI: 10.37482/0536-1036-2021-5-48-64

Seasonality and Species Specificity of Submerged Macrophyte Biomass in Shallow Lakes Under the Influence of Climate Warming and Eutrophication

Climate warming and eutrophication caused by anthropogenic activities strongly affect aquatic ecosystems. Submerged macrophytes usually play a key role in shallow lakes and can maintain a stable clear state. It is extremely important to study the effects of climate warming and eutrophication on the growth of submerged macrophytes in shallow lakes. However, the responses of submerged macrophytes to climate warming and eutrophication are still controversial. Additionally, the understanding of the main pathways impacting submerged macrophytes remains to be clarified. In addition, the influence of seasonality on the growth responses of submerged macrophytes to climate warming and eutrophication requires further elucidation. In this study, we conducted a series of mesocosm experiments with four replicates across four seasons to study the effects of rising temperature and nutrient enrichment on the biomass of two submerged macrophytes, Potamogeton crispus and Elodea canadensis. Our results demonstrated the seasonality and species specificity of plant biomass under the influence of climate warming and eutrophication, as well as the main explanatory factors in each season. Consistent with the seasonal results, the overall results showed that E. canadensis biomass was directly increased by rising temperature rather than by nutrient enrichment. Conversely, the overall results showed that P. crispus biomass was indirectly reduced by phosphorus enrichment via the strengthening of competition among primary producers. Distinct physiological and morphological traits may induce species-specific responses of submerged macrophytes to climate warming and eutrophication, indicating that further research should take interspecies differences into account.

Effect of epibrassynolide on the flavonoids content in plant sprouts under stress caused by N-phosphonomethylglycine

The effect of epibrassinolide (EBL) on the content of flavonoids in seedlings of fiber flax (Linum usitatissimum L.) and spring barley (Hordeum vulgare L.) under chemical stress caused by N-phosphonomethylglycine (glyphosate) was studied. The species specificity of the response of the seedlings to the introduction of EBL in a mixture with an inhibitory dose of glyphosate was noted. This specificity is expressed in the suppression of the inhibitory effect of glyphosate on the flavonoids' content in the tissues of fiber flax and the absence of changes in the level of the content of flavonoids in the roots and aerial part of spring barley seedlings.

The History, Landscapes, Metaphors and Ghosts Around the Concept of Specificity

The confusion between objects/processes and the language which describes them, leads to theories of doubtful verisimilitude about reality, inappropriate in time and even false, which distance us from the knowledge of perceived reality. In biology there are many examples of this kind of epistemological problem. Here we examine those related with specificity: a theoretical entity of enormous importance for biology and science in general. It sinks its roots beneath the evolutionary duality species-specificity, associated with the Linnean-Darwinist tradition that explains organized life in a discrete and hierarchical way. It conceptualizes the individual as an isolated agent fighting for survival as the foundation of a warrior vision of the immune system. Microorganisms are understood as inferior beings which should be eliminated in accordance with the self/not-self distinction. The use of these metaphors outside of historical context traces a map that guides the recognition of the Self and of the other according to the dialectic of Western biopolitics.