Week 7 Stem Cells - Holy

Question 1

Two fundamental characteristics of stem cells

Answer 1

self renew

produce daughter cell that can terminally differentiate

Question 2

Mechansims to promote stem cell DNA health

Answer 2

• Reduce number of divisions by using progenitor

- Immortal Strand hypothesis

Question 3

Natural types of stem cells

Answer 3

Embryonic- isolated from the inner cell mass or epiblast of blastocysts (don’t know if will cause cancer later on)

Adult - involved in replacing and repairing tissues in a particular organ (multipotent at best, low rate of cell division, do not proliferate rapidly)
—–Mesenchymal Stem cells (multipotent adult stem cells), found in bone marrow, identifiable, readily obtainable, and experimentally tractable

Question 4

Malignant Types of stem cells

Answer 4

Germ cells can exhibit pluripotency- occasionally these cells can become transformed and give rise to benign or malignant growths (teratocarcinomas)

Embryonal carcinomas- germ cell epigentetic reprogramming presumably underlies, poorly defines

Question 5

iPS method

Answer 5

Induced pluripotent stem cells

• pluripotency transcription factors (oct4, Nanog, Sox) transfected into differentiated cells and force them to be expressed
• cells revert back to more pluripotent state

Question 6

SCNT (somatic cell nuclear transfer method)

Answer 6

• Diploid adult nucleus is injected into oocyte (replacing oocyte genome)
• Demethylation and increase in potency that normally takes place after fertilization occurs and reprograms the somatic nuclei
• METHOD OF COLONING

Question 7

define niches

Answer 7

allow for controlled stem cell proliferation and differentiation of the progeny that leave the niche

-produce paracrine factors that regulate stem cell proliferation and prevent differentiation, once cells leave niche they begin differentiating