Stem Cells

Question 1

What are stem cells

Answer 1

Cells which are demonstrated to be both capable of self renewal and differentiation

Question 2

Describe what potency is

Answer 2

Potency is the ability a cell has to differentiate into different cell types. Totipotent cells can differentiate into all cell types including extraembryonic tissues. Pluripotent can differentiate into all somatic cells. Multipotent can differentiate into several somatic cells an unipotent can only differentiate into one cell type.

Question 3

Give examples of totipotent and pluripotent stem cell

Answer 3

totipotent= zygote
pluripotent= embryonic stem cells

Question 4

what are embryonic stem cells

Answer 4

cells derived in vitro from the inner cell mass of a blastocyst stage embryo

Question 5

What are the characteristics of embryonic stem cells

Answer 5

immortal

have few gap phases and divide very quickly in vitro

Question 6

How can pluripotency be induced

Answer 6

first found to be possible using OCT4, SOX2 KLF4 and cmyc by yamanaka in 2006 however since then many other combinations of factors have been found to induce pluripotency

Question 7

what are the problems with induced pluripotency

Answer 7

very inefficient

tumour formation

Question 8

what is another very important factor of culture of ESCS

Answer 8

LIF - for mice ESCs

human- grown on mouse embryonic fibroblasts

Question 9

what are the laws surrounding use of hESCs for research in UK

Answer 9

projects using hESCs must be granted specific liscence by HFEA
people donating gametes/embryos for this purpose must be specifically consented
no embryos created or used in research can be transferred to a woman in the UK
embryos are not allowed to develop in the lab beyond 14 days

Question 10

what is the HFEA stance of treatments using ‘artificial gametes’

Answer 10

currently only allow treatment with gametes produced or extracted for ovaries/testes’ as such currently only allowed for research