Guest Editor's Introduction. Controlling which genes are transcriptionally expressed is key to the generation and maintenance of the repertoire of cell types needed to support the mammalian lifestyle.

摘要

Unraveling the mechanisms involved in the progression from enjoying a romantic evening to having to pay college tuition has stimulated the creativity of many scientists. How does a fertilized egg develop into a young adult capable of comprehending the complexity of his or her own life? This miraculous development is possible because a single cell can become two and each may express the same or different genes potentially leading to tissue differentiation. Controlling which genes are transcriptionally expressed is key to the generation and maintenance of the repertoire of cell types needed to support the mammalian lifestyle. Although all phases of transcription are subject to regulation, control of elongation has emerged as especially important [1-6]. This issue of Methods was conceived in response to the growing emphasis in the field of eukaryotic transcription. The collection of articles will aid investigators in both the design and evaluation of experiments pertaining to RNA polymerase II elongation.