L4 - Stem Cells & Reproductive Ethics

what are stem cells

unspecialised cells that can reproduce indefinitely and differentiate into one or more specialised cells times

what are the 2 types of stem cells

embryonic and adult stem cells

what can stem cells do

generate tissues, organs or organisms

how many stem cell potencies is there

4

totipotent and example

generate all of the tissues of the embryo and the extra embryonic tissue such as the placenta, e.g. the zygote

pluripotent

generates cells from all three germ layers but not the extra embryonic tissue, e.g. embryonic stem cells

multipotent and example

ability to differentiae into multi lineages but not to all germ layers, e.g. mesenchymal stem cells

unipotent and example

ability to differentiate along only one lineage, e.g. most adult stem cells in differentiated undamaged tissues

what kind of stem cells are used in regenerative medicine and tissue engineering

totipotent and pluripotent stem cells

what type of potency do adult stem cells have

multipotent and unipotent

when are multipotent stem cells used

in treatments for blood disorders and tissue repair

when are unipotent stem cells used

for tissue-specific regeneration and repair

autologous

taken from an individual and returned to the same person

Allogenic

taken from an individual and returned to a different person

reproductive cloning - somatic cell nuclear transfer

the nucleus of a somatic cell from a donor organism is inserted into an egg cell that has had its nucleus removed. it is replaced with a nucleus of a differentiated cell. the egg is then stimulated to divide and develop into an embryo which can then be implanted into a surrogate mother to develop into a full organism

non-reproductive human cloning

the embryo is cultured for a short period and used to drive embryonic stem cells, these cells have the potential to develop into any cell type in the body offering possibilities for tissue repair, organ regeneration and the treatment of various diseases