lecture 26 - cellular differentiation & stem cells Flashcards
How does an embryo begin?
As a small number of equivalent/identical naïve totipotent cells that have the potential to give rise to any type of cell.
What is cell polarisation in terms of embryonic development?
When the nuclei of the cells move to one side of the cell and layer of micro vili forms on the outer sides of the cells , facing the inter uterine environment
What is the result of cell compaction in embryonic development?
The outer and inner cells begin to differentiate into the ICM (inner cell mass), and trophectoderm
What is the ICM, in terms of embryonic development?
Inner Cell Mass
What does the ICM (inner cell mass) give rise to?
Embryonic stem cells
What types of cells can embryonic stem cells give rise to?
All cell types except trophectoderm
What are trophectoderm cells?
Cells that give rise to the placenta during embryonic development.
How can the potency of embryonic stem cells be described?
Pluripotent
What does pluripotent mean, in terms of cell development?
Can give rise to a wide range of cells
In embryonic development, the progressive restriction of cell fate leads to?
The terminal differentiation of cells, so that individual cells can only form replicas of themselves and can opt change their fate.
How is the ‘fate’ of a pluripotent precursor embryonic cell decided?
Based on the genes that are turned on or off - certain genes code for certain transcription factors that allow specific proteins relevant to cell function to be manufactured.
What is the regulatory gene that controls the differentiation of an embryonic cell into a muscle cell component/myoblast?
myoD
What is the function of MyoD protein?
It is a transcription factor that allows a myoblast to develop into a muscle fibre by acting as a transcription factor to turn on genes that are relevant for muscle development (e.g. mysoin)
Where can human embryonic stem cells be harvested from?
The ICM of blastocyst embryos
What are induced pluripotent stem cells?
Cells made by reprogramming adult skin cells to become pluripotent - to mimic stem cells.