Gene Expression in Development

Question 1

what are totipotent cells?

Answer 1

• e.g cells of the very early mammalian embryo
• identical and unrestricted
• can give rise to any cell of body
• embryonic

Question 2

what are pluripotent cells?

Answer 2

• e.g inner cells of the blastocyst
• less potent
• can give rise to many cell types but not all
• embryonic

Question 3

what are multipotent cells?

Answer 3

• e.g. blood cells
• can give rise to cells that have a particular function
• adult

Question 4

what are the two stages of cell commitment?

Answer 4

1. specification - reversible

2. determination - itteversible

Question 5

what are features of specification stage?

Answer 5

capable of differentiating autonomously if placed in isolation BUT can be respecified if exposed to certain chemicals/signals

Question 6

what are features of determination stage?

Answer 6

cell will differentiate autonomously even when exposed to other factors or placed in a different part of the embryo

Question 7

what is cell fate?

Answer 7

what it will become in the course of normal development:

• when a cell “chooses” a particular fate it is said to be determined
• still looks like its undetermined neighbours
• determination implies stable change, fate of determined cells does not change

Question 8

what is competence of a cell?

Answer 8

ability of a cell to respond to the chemical stimuli - a cell can lose competence by changes in surface receptor or intracellular molecules

Question 9

how does a naive cell become specified?

Answer 9

by intrinsic or extrinsic signal:

intrinsic: (cytoplasmic determinant) - cell autonomous signal tells cell ‘who it is’
extrinsic: (induction) - a chemical or molecule in the environment gives cell spatial info, tells cell ‘where it is’

Question 10

what is brainbow technology?

Answer 10

• tracks neuronal development and cell fate
• cells tracked over time
• stochastic colour expression in neuronal cells