Introduction to development Flashcards
What does development rely on?
Patterns in gene expression.
The majority of processes in embryogenesis have been conserved across species. True or false?
True.
What is experimental embryology?
Transplanting cells to a new location or treating an embryo with drugs/gene products to observe the effects.
Basically fucking with embryos to see what happens cuz yolo
What is developmental genetics?
Looking at mutants to deduce the function of a gene.
What are the 7 major stages in embryonic development?
- Fertilisation
- Cleavage
- Gastrulation
- Axis determination
- Segmentation
- Neurulation
- Growth and differentiation
In what stage are the germ layers formed?
Gastrulation.
What are the 3 axes that must be established?
The anterior/posterior, dorsal/ventral and left/right axes.
Both mammals and invertebrates are internally segmented. True or false?
False - mammals are internally and invertebrates are externally segmented.
There are 3 stages to differentiation. What are they?
Commitment, specification, determination.
If a cell is uncommitted it is essentially totipotent. When it becomes specified it becomes multipotent, and when it is determined it only gives rise to one cell type. True or false?
True (I think).
You can reverse specification and determination. True or false?
False - certainly not in nature.
What are the 2 methods by which cells become specified to their fates?
- Conditional
2. Autonomous
What is conditional specification?
Specification is induced by cell-cell signalling, it depends on the environment.
What is autonomous specification?
Cytoplasmic determinants within the cell itself specify fate.
Define delamination.
When cells individually migrate away from an aggregation.
Drosophila neuroblasts are formed by the delamination of ectoderm. True or false?
True.
Drosophila neuroblasts display lateral inhibition. What is this?
They release negative signals onto the surrounding ectoderm cells to prevent them also becoming neuroblasts.
In drosophila what do achaete-scute mutants lack?
They have no neuroblasts.
What is the function of the achaete-scute gene?
Neuroblast determination.
In the notch-delta pathway, which is a) the signalling molecule and b) the receptor?
a) Notch
b) Delta
If you supress notch-delta in drosophila what happens, what does this show?
Deactivation causes all cells to become neuroblasts, thus notch-delta is important for normal ectoderm development.
After delamination, what kind of division do drosophila neuroblasts undergo?
Asymmetric division.
What causes asymmetric division?
Unequal distribution of chemicals in the cytoplasm.
What does the gene Miranda do?
Prevents the formation of neuroblasts.
What kind of cell is the gene Miranda found in?
Ganglion mother cells.
What are P-granules?
Germ cell determinants in C. elegans.
In normal development where are the P-granules?
Concentrated on one side of the cell.
What is the distribution of p-granules like in par-1 C. elegans mutants?
Even throughout the cytoplasm, thus the cells fail to segregate at division and no germ cells form.
