Genetic reprogramming following nuclear transplantation in Amphibia

Specialized cells are generally unable to switch from one type to another. For example, muscle cells can not be converted to intestine, brain, skin, etc. However, the nucleus of a specialized cell, such as muscle, can be transplanted to an enucleated egg, and the resulting combination will form all these and most other cell types. Likewise somatic cell nuclei injected into oocytes will switch their pattern of gene expression to conform to that of an oocyte, repressing some genes and activating others. This article reviews what is known of the mechanisms involved in these examples of nuclear reprogramming.