Publications by authors named "Xenia-Katharina Hoffmann"

Among the human milk oligosaccharides (HMOS), the galactosyllactoses (GLs) are only limitedly studied. This study aims to describe the presence and relative levels of HMOS, including GLs, in human milk (HM) according to maternal Secretor and Lewis () phenotype and lactation stage. Relative levels of 19 HMOS were measured in 715 HM samples collected in the first 4 months postpartum from 371 donors participating in the PreventCD study.

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Nonlinear dynamic processes involving the differential regulation of transcription factors are considered to impact the reprogramming of stem cells, germ cells, and somatic cells. Here, we fused two multinucleate plasmodial cells of Physarum polycephalum mutants defective in different sporulation control genes while being in different physiological states. The resulting heterokaryons established one of two significantly different expression patterns of marker genes while the plasmodial halves that were fused to each other synchronized spontaneously.

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Physarum polycephalum is a lower eukaryote belonging to the amoebozoa group of organisms that forms macroscopic, multinucleate plasmodial cells during its developmental cycle. Plasmodia can exit proliferative growth and differentiate by forming fruiting bodies containing mononucleate, haploid spores. This process, called sporulation, is controlled by starvation and visible light.

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The heterogeneity of cell populations and the influence of stochastic noise might be important issues for the molecular analysis of cellular reprogramming at the system level. Here, we show that in Physarum polycephalum, the expression patterns of marker genes correlate with the fate decision of individual multinucleate plasmodial cells that had been exposed to a differentiation-inducing photostimulus. For several hours after stimulation, the expression kinetics of PI-3-kinase, piwi, and pumilio orthologs and other marker genes were qualitatively similar in all stimulated cells but quantitatively different in those cells that subsequently maintained their proliferative potential and failed to differentiate accordingly.

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The first step in sexual differentiation of the unicellular green alga Chlamydomonas reinhardtii is the formation of gametes. Three genes, GAS28, GAS30, and GAS31, encoding Hyp-rich glycoproteins that presumably are cell wall constituents, are expressed in the late phase of gametogenesis. These genes, in addition, are activated by zygote formation and cell wall removal and by the application of osmotic stress.

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