Cell Differentiation Flashcards
List the main processes that occur during differentiation.
1 - Maintenance of stem cell pool through self-renewal (maintenance).
2 - Cell division and differentiation into progenitors (expansion).
3 - Terminal differentiation.
List the degrees of cell potency from most potent to least potent, and give examples of each.
1 - Totipotent.
2 - Pluripotent (most stem cells).
3 - Multipotent (progenitors).
4 - Unipotent (terminally differentiated cells).
List the line of progenitor cells that form red blood cells and platelets.
1 - Red blood cells start with erythroblasts, whereas platelets start with megakaryoblasts.
2 - Erythroblasts differentiate into reticulocytes, whereas megakaryoblasts differentiate into megakaryocytes.
3 - Reticulocytes differentiate into red blood cells, whereas megakaryocytes differentiate into platelets.
Give an example of a structural protein unique to erythrocytes.
Spectrins.
What are promoter sequences?
The regions of DNA that initiate transcription.
What are gene enhancers?
Regions of DNA that can be bound by activators to increase the likelihood that transcription of a particular gene will occur.
What are transcription factors?
- Proteins that bind to DNA sequences to control the rate of transcription of a particular gene.
- Transcription factors can also interact with RNA polymerase (e.g. to initiate transcription at promoter sequences).
What is erythropoietin?
A hormone secreted by the kidneys that stimulates the differentiation of progenitors into red blood cells.
What stimulates the kidneys to secrete erythropoietin?
- Low oxygen content in the blood at the proximal tubule.
- When oxygen content is high, the kidneys use negative feedback to reduce erythropoietin, thus creating a cycle.
