CBNS 121 QUESTIONS AND ANSWERS GRADED A+
Noggin - Answers - rescue ventralized embryos
- induce neural tissue in animal caps
Chordin - Answers - expressed in the organizer
- has neural inducing activity
What happens when TGF(beta) receptors are blocked? - Answers Mimics the effects of
Chordin/ Noggin
Follistatin - Answers Bind to TGF(beta) secreted signals and inhibit them
Which proteins inhibit TGF(beta) signals? - Answers - Noggin
- Chordin
- Follistatin
BMP - Answers Bone Morphogenetic Protein
What do BMPs do? - Answers Promote new bone growth, which is essential for developing
embryos
True/False
TGF(beta) receptors are BMPs. - Answers True
What does the loss of Noggin and Chordin do in mice? - Answers Causes severe defects in the
head and limits brain development
What is required for neural induction? - Answers - Activation of FGF signaling
- Blocking of BMP signaling
When is neural tissue induced? - Answers During Gastrulation
Where is the nervous system derived from? - Answers Ectoderm
Where do the signals for neural induction come from? - Answers Mesoderm
Spemann-Mangold Organizer - Answers A tissue that secretes a mixture of growth factor
antagonists, which are able to induce embryonic cell differentiation
Wnt - Answers - High in posterior embryo
- Wnt inhibitors in anterior mesoderm
, Wnt inhibitors - Answers - Dkk
- Cerberus
What happens when Dkk1 is removed? - Answers Hyperactive Wnt signaling
- lack a forebrain and anterior head structures
Retinoic Acid (RA) - Answers - Derivative of Vitamin A (retinol)
- Known to be powerful teratogen
- Levels are higher in posterior than anterior
- regulates HOX gene expression in vertebrates
Is RA signaling required for development? - Answers Yes;
- Reduction of RA acid synthesis affects HOX expression
- Embryos without RA die during embryonic development
Activators - Answers - BMP inhibitors
- FGF signaling
induce neural tissue with anterior characteristics
Transformers - Answers - RA
- Wnt
- FGF
- Otx2
- Gbx2
required to transform a portion of neural tissue to more posterior structures (i.e
hindbrain/spinal cord)
regulate the expression of TFs that repress each other
Otx2 - Answers -/- mutants lack a forebrain and anterior head structures
Noggin - Answers - rescue ventralized embryos
- induce neural tissue in animal caps
Chordin - Answers - expressed in the organizer
- has neural inducing activity
What happens when TGF(beta) receptors are blocked? - Answers Mimics the effects of
Chordin/ Noggin
Follistatin - Answers Bind to TGF(beta) secreted signals and inhibit them
Which proteins inhibit TGF(beta) signals? - Answers - Noggin
- Chordin
- Follistatin
BMP - Answers Bone Morphogenetic Protein
What do BMPs do? - Answers Promote new bone growth, which is essential for developing
embryos
True/False
TGF(beta) receptors are BMPs. - Answers True
What does the loss of Noggin and Chordin do in mice? - Answers Causes severe defects in the
head and limits brain development
What is required for neural induction? - Answers - Activation of FGF signaling
- Blocking of BMP signaling
When is neural tissue induced? - Answers During Gastrulation
Where is the nervous system derived from? - Answers Ectoderm
Where do the signals for neural induction come from? - Answers Mesoderm
Spemann-Mangold Organizer - Answers A tissue that secretes a mixture of growth factor
antagonists, which are able to induce embryonic cell differentiation
Wnt - Answers - High in posterior embryo
- Wnt inhibitors in anterior mesoderm
, Wnt inhibitors - Answers - Dkk
- Cerberus
What happens when Dkk1 is removed? - Answers Hyperactive Wnt signaling
- lack a forebrain and anterior head structures
Retinoic Acid (RA) - Answers - Derivative of Vitamin A (retinol)
- Known to be powerful teratogen
- Levels are higher in posterior than anterior
- regulates HOX gene expression in vertebrates
Is RA signaling required for development? - Answers Yes;
- Reduction of RA acid synthesis affects HOX expression
- Embryos without RA die during embryonic development
Activators - Answers - BMP inhibitors
- FGF signaling
induce neural tissue with anterior characteristics
Transformers - Answers - RA
- Wnt
- FGF
- Otx2
- Gbx2
required to transform a portion of neural tissue to more posterior structures (i.e
hindbrain/spinal cord)
regulate the expression of TFs that repress each other
Otx2 - Answers -/- mutants lack a forebrain and anterior head structures
