Early Development Amphibians. Cleavage in a frog Describe the progression of events.
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Transcript of Early Development Amphibians. Cleavage in a frog Describe the progression of events.
Gastrulation in Xenopus What happens at the mid-blastula transition
in preparation for gastrulation?
How is dorsal-ventral axis established?
What happens if cortical rotation is blocked?
Gastrulation in Xenopus How did Gimlich and Gerhart demonstrate that
certain cells were responsible for inducing dorsal lip formation?
Gastrulation in Xenopus What appears to be the major factor directing
movement of cells into embryo?
Gastrulation in Xenopus What two factors appear to drive
convergent extension? adhesion proteins paraxial and axial
protocadherin are expressed changes in calcium concentrations
Axis Formation What classic
experiment was done by Spemann and Mangold that led to the concept of the organizer?
Axis Formation How did work of
Nieuwkoop and Nakamura contribute to an understanding of how the “organizer” worked?
Axis Formation What is involved in the mechanism of
induction of mesoderm by endoderm?
What appears to be the role of β-catenin?
What is the connection between β-catenin and glycogen synthase kinase – 3 (GSK-3)?
The Organizer What are the four major functions of this
tissue? differentiate into dorsal mesoderm induce formation of paraxial mesoderm induce formation of neural tube initiate gastrulation movements
The Organizer What are the functions of the diffusable
proteins cerberus, dickkopf and Frzb?
How do these proteins work?
Induction Toivonen and Saxen postulated two
gradients in amphibian embryos dorsal gradient – “neuralizing” activity caudal gradient – “posteriorizing” activity
What is the primary protein involved in posteriorizing the neural tube?