Project description:Cellular binary fate decisions require the progeny to silence genes associated with the alternative fate. The major subsets of alpha:beta T cells have been extensively studied as a model system for fate decisions. While the transcription factor RUNX3 is required for the initiation of Cd4 silencing in CD8 T cell progenitors, it is not required to maintain the silencing of Cd4 and other helper T lineage genes. The other runt domain containing protein, RUNX1, silences Cd4 in an earlier T cell progenitor, but this silencing is reversed whereas the gene silencing after RUNX3 expression is not reverse. Therefore, we hypothesized that RUNX3 and not RUNX1 recruits other factors that maintains the silencing of helper T lineage genes in CD8 T cells. To this end, we performed a proteomics screen of RUNX1 and RUNX3 to determine candidate silencing factors.
Project description:Mesenchymal populations include a fraction of cells exhibiting multipotency as well as others with limited differentiation range. It has been assumed that the mesenchymal cellular cascade is topped by a multipotent cell, which gives rise to progeny with diminishing differentiation potentials. Here we show that cultured mesenchymal cells, a priori exhibiting a limited differentiation potential, may gain new capacities and become multipotent following single cell isolation. These fate changes were accompanied by up-regulation of differentiation promoting genes, many of which also became H4K20me1 methylated. Early events in the process included TGFβ and Wnt modulation, and down-regulation of hypoxia signaling. Indeed, hypoxic conditions inhibited the observed cell changes. Overall, cell isolation from neighboring partners caused major molecular changes and particularly, a newly established epigenetic state. It is suggested that MSCs behave non-deterministically and non-hierarchically and should therefore be defined primarily by their capacity to undergo fate changes triggered by environmental cues. The gene expression profile of dense and sparse MSC cultures in three sequential days after seeding was compared
Project description:Mesenchymal populations include a fraction of cells exhibiting multipotency as well as others with limited differentiation range. It has been assumed that the mesenchymal cellular cascade is topped by a multipotent cell, which gives rise to progeny with diminishing differentiation potentials. Here we show that cultured mesenchymal cells, a priori exhibiting a limited differentiation potential, may gain new capacities and become multipotent following single cell isolation. These fate changes were accompanied by up-regulation of differentiation promoting genes, many of which also became H4K20me1 methylated. Early events in the process included TGFβ and Wnt modulation, and down-regulation of hypoxia signaling. Indeed, hypoxic conditions inhibited the observed cell changes. Overall, cell isolation from neighboring partners caused major molecular changes and particularly, a newly established epigenetic state. It is suggested that MSCs behave non-deterministically and non-hierarchically and should therefore be defined primarily by their capacity to undergo fate changes triggered by environmental cues. The gene expression profile of MSC population was compared with one of its derived single cell clones
Project description:We collected whole genome testis expression data from hybrid zone mice. We integrated GWAS mapping of testis expression traits and low testis weight to gain insight into the genetic basis of hybrid male sterility.
