Lecture 22b Flashcards
What is Lineage Tracing?
This is when we attach a fluorescent protein to a cell & watch to see what forms from that original cell (aka its progeny).
What is “the identification of all progeny of a single cell”?
Lineage tracing
What is Fate Mapping?
A method used in developmental biology to study the embryonic origin of various adult tissues and structures.
What do Fate Maps show?
They show which parts of the embryo will develop into which tissue.
What is an example of Fate Mapping in humans?
Early in development, the human embryo is a disk but the cells in different parts of the disk have already been specified.
Which occurs first: cell determination or cell differentiation?
Cell determination
What is Cell Determination?
This is where a cell is destined/predetermined to become a particular cell type.
What is Cell Differentiation?
When a cell’s morphology and function have changed (usually permenantly) into a specialized cell type.
T/F: There aren’t any specific genes that cause cells to differentiate.
False! Researchers have identified specific genes that cause cells to differentiate into particular cell types.
These genes trigger undifferentiated cells to differentiate into their proper cell fates.
What are the 4 genes that initiate muscle development?
MyoD, Myogenin, Myf5, and Mrf4
What do MyoD, Myogenin, Myf5, and Mrf4 encode for?
Encode transcription factors that contain a basic domain and a helix-loop-helix domain.
What does a Basic Domain do?
Binds DNA and activates skeletal muscle specific genes.
What does a Helix-Loop-Helix Domain do?
It is necessary for dimer formation between transcription factor proteins.
Collectively, what are MyoD, Myogenin, Myf5, and Mrf4 called?
Myogenic bHLH proteins
Where are Myogenic bHLH proteins found?
Found in all vertebrates and even some invertebrates (Drosophila and C. elegans)
When are Myogen bHLH proteins activated?
During skeletal muscle development
What does the expression of Myogen bHLH proteins do?
Expressing them drives muscle development (the production of muscle).
What is the central issue in population genetics?
Genetic variation, specifically, its extent within populations, why it exists, and how it changes over the course of many generations.
What is a Gene Pool?
All of the alleles of every gene in a population.