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Two separate experiments were performed to analyze the effects of different media on gynogenic regeneration in four onion cultivars. In a two step flower/ovary culture procedure, 2,4-dichlorophenoxyacetic acid added to the induction medium was superior to phenylacetic acid in the highly regenerating cultivar, while the effect of thidiazuron in the regeneration medium was generally optimal in higher (2 mg/l) rather than in lower (0.2 mg/l) concentrations. Gellan-gum was compared to agar solidified media. A higher number of regenerants was achieved on the former, but an undesirable hyperhydricity of regenerants formed on gellan-gum solidified media greatly reduced the final survival of formed embryos. Analysis of the time interval needed for regeneration showed high variability (from 46 to 152 days after inoculation), which was particularly pronounced in genotypes with lower regeneration capacity. Simpler isozyme patterns of regenerants showed that all analysed regenerants of the cultivar with a high regeneration capacity were homozygous, while in the other three cultivars, a considerable percentage (11.1 to 36.4%) of heterozygous regenerants were also detected. Ploidy analysis of the regenerants with simpler isozyme patterns revealed that the majority of lines remain haploid. Identification of 2 homozygous triploid regenerants demonstrated that as in androgenesis, nuclear fusions can occur during gynogenic haploid regeneration.

ObjectiveTo estimate the incidence and describe the spectrum of inflammatory and autoimmune diseases linked to SARS-CoV-2 infection and COVID-19 vaccination in children from two neighbouring south central European countries. MethodsWe performed a multi-centre prospective cohort study of children under 18 years diagnosed with inflammatory/autoimmune diseases linked to SARS-CoV-2 infection or COVID-19 vaccination, who were admitted to the paediatric tertiary care hospitals

IntroductionAlthough children seem to be less susceptible to COVID-19, some of them develop a rare but serious hyperinflammatory condition called multisystem inflammatory syndrome in children (MIS-C). While several studies describe the clinical conditions of acute MIS-C, the status of convalescent patients in the months after acute MIS-C is still unclear, especially the question of persistence of changes in the specific subpopulations of immune cells in the convalescent phase of the disease.MethodsWe therefore analyzed peripheral blood of 14 children with MIS-C at the onset of the disease (acute phase) and 2 to 6 months after disease onset (post-acute convalescent phase) for lymphocyte subsets and antigen-presenting cell (APC) phenotype. The results were compared with six healthy age-matched controls.ResultsAll major lymphocyte populations (B cells, CD4 + and CD8+ T cells, and NK cells) were decreased in the acute phase and normalized in the convalescent phase. T cell activation was increased in the acute phase, followed by an increased proportion of γ/δ-double-negative T cells (γ/δ DN Ts) in the convalescent phase. B cell differentiation was impaired in the acute phase with a decreased proportion of CD21 expressing, activated/memory, and class-switched memory B cells, which normalized in the convalescent phase. The proportion of plasmacytoid dendritic cells, conventional type 2 dendritic cells, and classical monocytes were decreased, while the proportion of conventional type 1 dendritic cells was increased in the acute phase. Importantly the population of plasmacytoid dendritic cells remained decreased in the convalescent phase, while other APC populations normalized. Immunometabolic analysis of peripheral blood mononuclear cells (PBMCs) in the convalescent MIS-C showed comparable mitochondrial respiration and glycolysis rates to healthy controls.ConclusionsWhile both immunophenotyping and immunometabolic analyzes showed that immune cells in the convalescent MIS-C phase normalized in many parameters, we found lower percentage of plasmablasts, lower expression of T cell co-receptors (CD3, CD4, and CD8), an increased percentage of γ/δ DN Ts and increased metabolic activity of CD3/CD28-stimulated T cells. Overall, the results suggest that inflammation persists for months after the onset of MIS-C, with significant alterations in some immune system parameters, which may also impair immune defense against viral infections.

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