Reprogramming of Somatic Cell Identity

摘要

All mammalian somatic cells originate from a single fertilized cell, the zygote, and share identical genetic information despitethe dramatic changes in cell structure and function that accompany organismal development. The genome is subjected to a widearray of epigenetic modifications during lineage specification, a process that contributes to the implementation and mainte-nance of specific gene expression programs in somatic cells. Nuclear transfer and cell-fusion experiments demonstrate that theepigenetic signature directing a cell identity can be erased and modified into that of another cell type. Furthermore, in the caseof cloning, differentiated cells can be reprogrammed back to pluripotency to support the reexpression of all developmental pro-grams. Recent breakthroughs highlight the importance of transcription factors as well as epigenetic modifiers in the establish-ment, maintenance, and rewiring of cell identity. By focusing on reprogramming of terminally differentiated lymphocytes, wereview and highlight recent insights into the molecular mechanisms and cellular events potentially underlying programmingand reprogramming of somatic cell identity in mammals.