Lecture 5

Question 1

Cell Fate

Answer 1

• Asymmetric division: child cells born with different fates
• Symmetric division -> signal: Child cells born same, acquire different fates

Question 2

Asymmetric Division

Answer 2

• Cell fate markers unevenly distributed before division
• After division, one child cell inherits more of cell fate marker

Question 3

Lateral Inhibition

Answer 3

• Lateral inhibition creates a pattern of isolated differentiated cells in a field of relatively undifferentiated cells
• Active notch inhibit cell specialization

Question 4

Diffusible signals

Answer 4

• Morphogens are diffusible signals that affect cell differentiation -> diffuse and act on nearby cells
• Cells respond to morphogenetic by taking on new cell fate
• Cells can respond differently to same morphogenetic given at different concentrations

Question 5

Cell differentiation

Answer 5

• Totipotent cells: Become any cell type
• Pluripotent: Cells can become any adult cell type
• Multipotent: Cells can become multiple cell types

Question 6

Regulatory Hierarchies

Answer 6

• Same morphogenetic produced by cell type C can have different effects on cell types A and B
• Divide body into segments

Question 7

Hox gene

Answer 7

• Hox gene expressed in different segments and specify different body parts
• Hox genes organized on chromosomes in order of expression
• Hoox genes determine which body parts will determine from a segment
• Humans have 4 copies of hox complex
• Encode transcription factors