Skeletal muscle tissue is characterized by ability to regenerate in response to injury resulting for example from mechanical trauma, toxin or disease. The key role in this process is played by satellite cells localized in skeletal muscle. However, both under physiological and experimental conditions different types of stem cells originating either from skeletal muscle or other tissues can be also involved in regeneration. This raises the hope for potential use of stem cells in the therapy for skeletal muscles diseases, such as muscular dystrophies or spinal muscle atrophy.

In 2006 first paper describing reprogramming of fibroblast into pluripotent cell, i.e. one that is able to differentiate into all tissues was published. Before that spectacular achievement many projects devoted to study the mechanisms of cell de-differentiation led to the establishment of animal cloning techniques and also derivation of embryonic stem cell lines. Present review summarizes the history of these studies and also describes pioneer works leading to derivation of induced pluripotent stem cells, current methods of reprogramming, and possible applications of these cells.

Maturing vertebrate oocytes become arrested in metaphase of the second meiotic division. These oocytes are ovulated, and then can be activated by sperm or parthenogenetic stimulus. Metaphase arrest is mediated by the cytostatic activity – CSF, that prevents the inactivation of the major M-phase regulator i.e. CDK1-cyclin B kinase. CSF inactivation seems to be necessary for the completion of the second meiotic division and the initiation of the embryonic development. Analysis of amphibian oocyte maturation led to the discovery of factors crucial for the CSF activation.