W2: Molecular Regulation of Development Flashcards
___ gradient dictates differentiation of dorsal-ventral differentiation.
BMP - bone morphogenetic protein
Dorsal - minimum
Ventral - max
What regulates differentiation of mesodermal cells?
BMP
There is high/low BMP signaling at the lateral plate.
High (max at ventral)
There is intermediate BMP signaling at the ___.
somite
There is high/low BMP signaling at the notochord.
low
___ protein is inhibitor of BMP, a BMP antagonist.
Chordin
Chordin is an extracellular protein that binds ___, preventing it from binding to its receptor.
BMP
At the dorsal/ventral end, the BMP cannot be signaled.
Dorsal (minimal BMP due to Chordin)
Formation of dorsal/ventral tissues dictated by Spemann organizer
dorsal
DV cell differentiation:
AP patterning:
BMP, Chordin/Noggin
Hox gene
D - __ control
V - __ control
D - Chordin/Noggin control
V - BMP control
There is spatial and temporal collinearity in ___ gene expression.
hox
What is a signaling molecule that induce cell fates during embryo development (examples) and where does it come from?
Morphogen (Chordin)
come from organizing center
What is TGFβ?
Transforming growth factor beta
Largest family of growth factors (ex. BMP)
What is BMP?
Bone Morphogenic Proteins
A growth factor that induces cell differentiation at DV axis
What is a Hox gene and why is it significant?
Aka. homeobox gene
Gene that codes for DNA binding protein that provide regional identity at the AP axis
What is BMP4? Where is it secreted from and what does it do?
Growth factor that induces the ventral tissue;
secreted from ventral mesoderm
What is Chordin? Where is it secreted from and what does it do?
Secreted protein that induces neural tissue in dorsal ectoderm;
secreted from the dorsal (Spemann) organizing tissue (inhibit BMP)
Where does BMP act in the embryo? Chordin?
BMP acts on ventral side
(BV)
Chordin acts on dorsal side (inhibiting BMP)
(CD)
What is Rhombomere 3 and its significance in RA exposure of embryo?
Anterior-most border of Hox gene expression that corresponds to hindbrain segment. RA exposure can have detrimental impact on brain development by ectopic expression.
What happens when embryo is treated with RA?
Anterior boundaries of Hox gene expression move more anteriorly, expressing ectopically in the anterior region (around the head)
What is RA? What effect does it have on the embryo and what is the mechanism behind it?
RA is a ligand that binds to an NR called RAR, ultimately turning on transcription that leads to ectopic activation of Hox genes during the embryo’s development (in the head and CNS).
Regulators at
D-V axis:
A-P axis:
D-V axis: BMP/Chordin
A-P axis: Hox gene
retinoic acid (RA or accutane) is associated with AP/DV axis.
AP (hox gene)
