Definitions

Question 1

Stem Cell

Answer 1

An undifferentiated cell of a multicellular organism that is capable of giving rise to indefinitely more cells of the same type (self renewal) and from which other kinds of cell arise by differentiation.

Question 2

Potency

Answer 2

The sum potential of a cell to give different specialised cell types

Question 3

Totipotent

Answer 3

Can give rise to all cell types in the embryo and adult (eg, embryo and extra embryonic tissues). Source = zygote and 4 stage cleavage blastomere

Question 4

Pluripotent

Answer 4

Can give rise to cells of all body lineages (eg, the 3 germ layers). source = blastocyst

Question 5

Multipotent

Answer 5

Can give rise to a limited number of cell types in the body, (eg, all cells of one tissue type)

Question 6

Unipotent

Answer 6

Can give rise to only a single cell type, eg, spermatogonial stem cell

Question 7

Transdifferentiation

Answer 7

The notion that tissue stem cells can have a dormant broadened potency and can generate cells of other lineages under certain circumstances

Question 8

Defining characteristics of stem cells

Answer 8

1. Self renewal
2. Retain the ability to divide throughout life
3. Give rise to progenitors

Question 9

Cellular Pluripotency

Answer 9

Morphology, markers, cell cycle analysis.

Indicated cells share characterises with undifferentiated ES cells.

Rapid, but non-specific and the markers mate be expressed on non-pluripotent cells

Question 10

Molecular Pluripotency

Answer 10

RT-PCR, microarray and epigenetic analysis.

Determines cells are undifferentiated

Fast and simple, but not totally accurate and doesn’t determine capacity for differentiation.

Question 11

Functional Pluripotency

Answer 11

Embryoid body formation, teratoma, directed differentiation.

Assays ability to form 3 germ layers

Determined broad and specific differentiation capacity

EB- no tissue or structure formation
T- time consuming

Question 12

Development Pluripotency

Answer 12

Chimeras

Assays ability to contribute to all cell types in the adult organism

Most stringent test

Not ethical for humans

Question 13

Naive Pluripotency

Answer 13

The ability of a cell to self-renew while retaining the potential for unbiased differentiation into all 3 germ layers and germline contribution.

Question 14

Primed Pluripotency

Answer 14

Reached at the epiblast stage in preparation for gastrulation and organogenesis. Different to naïve pluripotent in that they cannot contribute to the chimera and cant form the germline.

Question 15

Stem Cell Niche

Answer 15

A microenvironment within a specific anatomic location where stem cells are found, which interacts with the stem cells to regulate cell fate.

Question 16

Mesenchymal stem cell

Answer 16

Non-haematopoetic stem-like cells that can be isolated from most mesenchymal tissues such as bone marrow, fat, blood vessels and umbilical cord

In culture, described as plastic adherent, fibroblast like cells which can self-renew and differentiate into bone, adipocyte and cartilage

Question 17

Embryoid Body

Answer 17

A clump of cells that arises when embryonic cells are cultured and differentiated in suspension and that can give rise to cell types of all 3 germ layers