I. Bioethics
You should be able to answer basic questions about pre-embryo biopsy, including how the procedure is performed.
II. Gastrulation
Cell Movements During Gastrulation
What are the basic types of cell movements that take place in gastrulating embryos? Can you think of specific examples of these movements?
Blastula Structure and Gastrulation
How does the yolk content of the egg affect blastula structure and gastrulation movements? What does gastrulation accomplish?
Sea Urchin Gastrulation
What changes in adhesive affinity take place as primary mesenchyme cells ingress? How do we know that these changes take place? What are some ideas put forward to account for the initial invagination of the archenteron? How does cell rearrangement result in lengthening of the archenteron? How do we know that rearrangement takes place? What role do the filopodia of secondary mesenchyme cells play during sea urchin gastrulation? What experiments tell us about their role? What experiments indicate that local pattern information is present in the sea urchin embryo for both primary and secondary mesenchyme cells ? What role does the extracellular matrix play during sea urchin gastrulation?
Amphibian Gastrulation
What major things does gastrulation accomplish in amphibians (list as many as you can think of!)? What are the major territories in a Xenopus gastrula? What basic sorts of movements do each of these regions perform? How do the deep cells of the involuting marginal zone differ from the surface (superficial) cells of the marginal zone [Hint: superficial cells of the IMZ are endoderm; what do they become? Deep cells are mesoderm]? How is blastopore closure accomplished? What do Keller "sandwiches" do? How can we use cells explanted in vitro to study gastrulation movements in more detail? What role(s) does fibronectin in the extracellular matrix probably play during leading edge mesoderm migration? What experiments indicate this?
Zebra Fish Gastrulation
How are zebrafish and amphibian gastrulation similar? Different? How is the embryonic shield similar to the dorsal involuting marginal zone of Xenopus? What does the half baked mutant tell us about the necessity for epiboly during zebrafish gastrulation? How can we use mutants to analyze cell migration during zebrafish gastrulation? What does the appearance of somites in spadetail and trilobite embryos tell us about possible defects in gastrulation in these mutants?
Chick and Mammalian Gastrulation
How does the hypoblast arise in chicks? How does the formation of the presumptive endoderm differ from amphibians? How is Henson's node similar to the dorsal blastopore lip in an amphibian? How do cells move through the primitive groove during chick gastrulation? How is regression of Henson's node coupled with formation of the notochord? What is the head, or notochordal process? What are the two basic types of cells in early mammalian embryos? What do trophoblast cells make? Inner cell mass cells? How do chick and human gastrulation compare? How is convergence and extension similar among frogs, chicks, mammals, and fish?
III. Neuralation and Neural Ectoderm
Neuralation
What are the basic events of neurulation? How do neural crest cells arise during neurulation? What ideas have been put forward to account for neurulation? What experiments support these ideas? How does the notochord interact with the neural plate in chicks, and why is that significant for morphogenesis? How does the neural plate region change overall shape (i.e., it rolls up, but what else happens?)? What are the two basic types of tissue in the ectoderm? How do their behaviors differ? What role does N-cadherin play during neurulation?
Central Nervous System Differentiation
How do the brain vesicles form? What mechanisms may be partly responsible for this? What major brain structures form from the various brain vesicles found at various stages of human development? What structures give rise to the retinas of the eyes? The lenses? What role does N-cadherin appear to play in optic vesicle formation? What is a rhombomere?
IV. Mesoderm and Endoderm
Notochord and Somites
How does the notochord form? What do Keller explants tell us about notochord formation? What are somitomeres? What changes take place in somites as they form? What are three basic tissues that derive from somitic mesoderm? What do they make?
Lateral Mesoderm
What are the two basic types of lateral mesoderm? What are the somatopleure and the splanchnopleure, and what tissue layers are they made from (i.e., they're double-layered!)? What is the central body cavity between these layers?
Endoderm
What major structures are formed by budding from the primary endodermal tube formed by ventral bending of the
embryo (e.g., lungs, pancreas, liver, endocrine portion of pituitary, etc.)? What are pharyngeal pouches?
Extraembryonic Membranes
What is an amniote? What animals have amniotic eggs, and how do these eggs allow them to survive on land? How are the splanchnopleure and the somatopleure modified in amniotes? What are the four major extraembryonic membranes, and what are their functions? How is the chorion modified in mammals? The allantois? What does the allantois help to form in mammals? What is chorionic villus sampling ? Amniocentesis ?
Blood and Blood Vessels
What are blood islands (also known as angiogenetic cell clusters)? Where do they form, i.e., what extraembryonic membrane is involved? How does the heart in amniotes form? What happens if ventral migration of the heart primordia is prevented? What role do stem cell populations play in blood cell differentiation? What is a growth factor? What is erythropoetin? What is vascular endothelial growth factor (VEGF)?What modifications are found in the fetal circulatory system to support gas and nutrient exchange with the placenta at various times during fetal development?
Bone Formation
What are the two major ways bone forms in higher vertebrates? What is endochondral ossification? Intramembranous ossification? What are bone morphogenetic proteins? What does the short ear mutation tell us about the role of BMPs in skeletal patterning? What role do fibroblast growth factor receptors play in bone development? How do we know?
V. Things To Know Exclusively From Your Readings
You need to know about brain vesicles and what they form.
