Pulsed induction, a method to identify genetic regulators of determination events

Abstract

Determination is the process in which a stem cell commits to differentiation. The process of how a cell goes through determination is not well understood. Determination is important for proper regulation of cell turn-over in tissue and maintaining the adult stem cell population. Deregulation of determination or differentiation can lead to diseases such as several forms of cancer. In this study I will be using microarrays to identify candidate genes involved in determination by pulse induction of mouse erythroleukemia (MEL) cells with DMSO and looking at gene expression changes as the cells go through the early stages of erythropoiesis. The pulsed induction method I have developed to identify candidate genes is to induce cells for a short time (30 min, 2 hours, etc.) and allow them then to grow for the duration of their differentiation time (8 days). For reference, cells were also harvested at the time when the inducer is removed from the media. Results show high numbers of genes differentially expressed including erythropoiesis specific genes such as GATA1, globin genes and many novel candidate genes that have also been indicated as playing a role in the dynamic early signaling of erythropoiesis. In addition, several genes showed a pendulum effect when allowed to recover, making these interesting candidate genes for maintaining self-renewal of the adult stem cell population.