BB 1035 Chapter XIX: Differential Gene Expression in Development


Terms in this set (...)

4 steps of development?
1. Determination
2. Differentiation
3. Morphogenesis
4. Growth
Develop fate of cell
Different types of cells arise; specific structures and functions
Organization and spatial distribution of differentiated cells into multicellular body and organs
Increase in size of body and organs by cell division/enlargement
Cell potency?
Cell's potential to differentiate into other cell types
4 types of cell potency? Describe
1. Totipotent - differentiate into any cell type
2. Pluripotent - differentiate into most other cell types, but not embryonic
3. Multipotent - differentiate into several different but RELATED cell types
4. Unipotent - can only produce their own cell type
In G1-S transition, what does cyclin CDK do?
Cyclin-cdk catalyzes phosphorylation of RB (retinoblastoma) protein
Phosphorylation causes 3D change in RB structure
What does the RB protein do?
Inhibits cell cycle from continuing
What does the change in RB structure result in?
RB no longer inhibiting cell cycle, cell cycle continues when RB phosphorylated
If DNA damaged in G1 checkpoint, what happens?
Cell signaling releases p21 (protein) that binds to G1-S cdk, preventing cyclin activation
Important enzyme for apoptosis? How does it work?
Caspases = proteases that hydrolyze target molecules in cascade of events

Cell dies as caspases hydrolyze proteins of nuclear envelope, nucleosomes, and plasma membrane
Positive regulator in cancer cells derived from normal positive regulators that have become overly active; always stimulate cell division
3 subphases of interphase? When is DNA replicated?
1. S - DNA replication
2. G1
3. G2
What is the only phase where crossing over can occur?
Prophase I
What does ESC stand for?
Embryonic stem cells
DNA sequence found in Hox genes that code for txn factors. What is it and what does it code for?
Homeobox - aa sequence codes for is called homeodomain
genomic equivalence?
no info lost from nuclei of cells as they pass through early stages of embryonic development