ABSTRACT
In this chapter, the authors focus on the types of inputs received by stem cells and how these influence cellular processes that ultimately determine their specific characteristics. They take a closer look at some of cellular processes that interpret the signaling inputs, including epigenetic modifications of histones, transcriptional control of gene expression, and micro RNAs as transcriptional and post-transcriptional regulators. Adult stem cells can be shown to be highly dependent on specific combinations of transcription factors, but unlike the way in which a defined set of transcription factors determine the pluripotent state. Exploring whether a specific pattern of histone modifications characterize adult stem cells, either in the quiescent state or linked to commitment to differentiation, has been technically more challenging because of the difficulty in obtaining enough cells. Downstream of the signal transduction inputs, additional specificity in the interpretation of signal can be ascribed to several of the molecular processes that lead to eventual change in overall activity of proteins.
