BIOL 2021 Chapter Notes - Chapter 23: Fibroblast, Somatic Cell Nuclear Transfer, Myocardial Infarction
12 May 2013
School
Department
Course
Professor
Document Summary
Cell specialization: terminal cell differentiation final specialization, usually stop dividing permanently enter the g0 stage, making different proteins (structural ion channels and signals for gene regulatory proteins) Classic nuclear transplantation experiment: **egg reprogrammed** - skin nucleus acts as an embryonic nucleus, different gene regulatory proteins no dna change. Daughter cells can remain stem cells or differentiate. Examples of stem cells in adult: epidermal (epidermis of skin), intestinal (epithelium of gut), hemopoietic (blood) Stem cells are rare and divide slowly: only 1 in 10000 are stem cells. Divide rapidly, but limited number of divisions, then differentiate. Advantages: division rate increases rapidly (can rapidly repopulate, reduce the chances of mutations in stem cells. Cancer arises in normal stem cells or transit amplifying cells. Only stem cells last long enough so cancer stem cells maintain the tumor: divide slowly but indefinitely. What defines a stem cell at a molecular level: we don"t know. Adult stem cells: hematopoeitic stem cells.
