Project description:Due to deposition of birds' guano, eggshells or feathers, the vicinity of a large seabirds' breeding colony is expected to have a substantial impact on the soil's physicochemical features as well as on diversity of vegetation and the soil invertebrates. Consequently, due to changing physicochemical features the structure of bacterial communities might fluctuate in different soil environments. The aim of this study was to investigate the bacterial assemblages in the Arctic soil within the area of a birds' colony and in a control sample from a topographically similar location but situated away from the colony's impact area. A high number of OTUs found in both areas indicates a highly complex microbial populations structure. The most abundant phyla in both of the tested samples were: Proteobacteria, Acidobacteria, Actinobacteria, and Chloroflexi, with different proportions in the total share. Despite differences in the physicochemical soil characteristics, the soil microbial community structures at the phylum level were similar to some extent in the two samples. The only share that was significantly higher in the control area when compared to the sample obtained within the birds' colony, belonged to the Actinobacteria phylum. Moreover, when analyzing the class level for each phylum, several differences between the samples were observed. Furthermore, lower proportions of Proteobacteria and Acidobacteria were observed in the soil sample under the influence of the bird's colony, which most probably could be linked to higher nitrogen concentrations in that sample.
Project description:The naïve mouse embryonic stem cells, characterized by high nuclear/cytoplasmic ratio, and dome-shaped colonies with smoothly contoured edges, exhibit self-renewal and pluripotency. However, it is unclear about the biological significance of dome-like morphology in relation to pluripotency. Here, we generate stable ES cell lines with a flat morphology, capable of sustained monolayer growth and efficient single-cell clonogenic capacity, by knocking out non-muscle myosin heavy chain IIA. Notably, even when deprived of the typical dome-like colony morphology, the ES cells retain their self-renewal capacity and pluripotency to differentiate into the three germ layers. Our data disprove the long-standing paradigm in stem cell field that the dome-shaped colony architecture is intrinsically linked to naïve pluripotency, instead demonstrating that core pluripotency circuitry operates independently of this morphological constraint.