Stem Cells Worksheet Flashcards
What are transit amplifying cells? Why are transit amplifying cells important to tissue homeostasis?
rapidly proliferating cells that undergo several divisions before they differentiate; they’re an intermediate cell between the initial stem cell and the final, fully differentiated cell
Compare the developmental potency of totipotent, pluripotent, and multipotent committed stem cells. Describe where in the embryo or adult body you would find each type.
> totipotent - produce cells of all tissue types; zygotes1-8 cell stage
pluripotent - increasingly committed to a single cell lineage; beyond 8 cell stage
multipotent - restricted differentiation; bone marrow (hematopoietic stem cells)
What are the 4 sources of stem cells, their potencies, and potential or current uses?
- embryonic - pluripotent - cell lines
- adult - committed, or multipotent - tissue maintenance
- umbilical cord - multipotent - hematopoietic
- induced pluripotent - pluripotent - differentiate into cells of all 3 germ layers and germ line
What is stem cell therapy?
use of stem cells to treat or cure a disease
How are embryonic stem cells isolated? How can they be used in regenerative medicine?
inner cell mass is removed from blastocyst, placed in a culture dish on a feeder layer of fibroblasts, colony forms, colony disrupted and replated, repeat to form cell line; grow them under conditions that promote differentiation into something specific
What is the difference between reproductive and therapeutic cloning?
reproductive: blastocyst implanted in mother and offspring is clone of individual who donated the somatic cell nucleus
therapeutic: blastocyst is used to make embryonic stem cells
What is somatic cell nuclear transfer? What is the nature of the genome of the blastulas derived from somatic cell nuclear transfer? How does this impact the use of these blastulas in subsequent cloning procedures?
nucleus is removed from somatic cell, nucleus also removed from oocyte, nucleus from somatic cell transferred into oocyte cytoplasm, oocyte then stimulated to begin developing as an embryo; the genome is exactly like whomever donated the nucleus; if the donor has traits you do not want, then you need to select another nucleus donor
How are stem cells used to produce transgenic animals?
obtain stem cells from mouse (ex.) w/ black coat color, cells grown an introduced into embryonic stem cellls, colony injected into blastocyst of a white mouse, blastocysts implanted in foster mother, pups will be chimeras- showing both black and white colors
What is the role of stem cells in tissue maintenance and repair? Which type of stem cells participates in tissue homeostasis? What is their developmental potency?
divide and differentiate to cell types that are needed; committed precursor; multipotency
Which type of stem cells is found in umbilical cord blood? What is their potential for use in stem cell therapy?
hematopoietic stem cells; alternative to bone marrow transplantation
What are induced pluripotent stem cells - how are they produced? What maintains the pluripotent state in stem cells? What advantages do they have? What is transdifferentiation?
reprogrammed adult somatic cells; Oct4, Sox2, and Nanog TF’s; they form positive autoregulatory loops as well as activate genes that maintain pluripotency and repress genes that induce differentiation; somatic cells can be reprogrammed to other types of differentiated cells with the right combo of TF’s - heart muscle & nerve cells for ex.
What are the primary concerns of implementing any stem cell therapy strategy? What are the potential advantages and disadvantages to each type of stem cell for use in stem cell therapy?
> efficacy, safety, immune rejection;
embryonic - proliferation w/o feeder layers, differentiation factors, full functional diff., and ethical
adult - ID and isolation, differentiation, genetic defects
advantages???
What is a stem cell? What properties make a stem cell different from other cells in the body?
an undifferentiated cell that is capable of giving rise to more cells of the same type, and from which certain other kinds of cells arise by differentiation; self-renewal and differentiation
