Early Development of Vertebrates Fish, Birds, and Mammals.

Early Development of Vertebrates

Fish, Birds, and Mammals

Zebrafish Development

Cleavage in Zebrafish

What kind of cleavage occurs in fish?

Cleavage in Zebrafish

At the time of the mid-blastula transition three cell populations form:yolk syncytial layer (YSL)enveloping layer (EVL)deep cells

What is the importance of each?

Gatrulation in Fish

How does gastrulation begin?

Gastrulation in Fish

What is the germ ring in the developing embryo?

How does hypoblast form?

Gastrulation in Fish

What is the role of convergence and extension?

Axis Formation in Fish

How has it been demonstrated that the embryonic shield is critical to dorsal-ventral axis formation?

What structures form from it?


How does notocord induce neural structures from overlying ectoderm?


Where is the Nieuwkoop center and how does it function?

What determines the anterior-posterior axis?

Cleavage in Birds

What kind of cleavage occurs in birds?

Cleavage in Birds

What is the area pellucida, area opaca and subgerminal cavity?

Gastrulation in Birds

How is the two-layered blastoderm formed?


What is the primitive streak?


What is important about the primitive groove?

the primitive knot or Henson’ node?

How does the primitive streak define the embryonic axes?


What is the fate of cells migrating through the primitive streak?


What happens to the primitive streak?


What is needed to complete the process of gastrulation?

Axis Formation in Birds

How does the pH influence the formation of the dorsal-ventral axis?

How do we know this is true?


How goes gravity influence formation of anterior –posterior axis?


How does formation of Nieuwkoop center in birds compare with amphibians?


From where does the “organizer” in the chick form?


How is left-right axis formed?

How has this been demonstrated experimentally?

Early Mammalian Development

What makes mammalian cleavage unique?


What is compaction and when does it occur?


How is trophoblast different from inner cell mass?

How does blastocyst form from morula?

Early Mammalian Development What enables the blastocyst to attach to the

uterus?

Gastrulation in Mammals

Development is internal. What modifications to the anatomy does this involve?

Derivation of Mammalian Tissues


gastrulation begins at the posterior end of the embryo

What appears to control cell migration and specification?


precursors of ectoderm are anterior to primitive streak

human hypoblast cells are replaced by endoderm precursors

Extraembryonic Membranes

Extraembryonic Membranes

How does placenta provide nutrients and oxygen to fetus?

Anterior-Posterior Axis Formation

Where are the two signaling centers located in the mammalian embryo?


How is mouse node and AVE similar to chick and frog organizer tissues?


What kind of interactions occur between visceral endoderm and epiblast in mice?


What is believed to be the role of the Hox genes?


What kind of evidence has enabled us to break the Hox gene code?knockout experimentsexperiments with retinoic acidcomparative anatomy studies


What was shown to occur when the Hoxa-3 gene was “knocked out”?

the Hoxa-2 gene?


How has the application of retinoic acid provided us information about hox genes?


What is the connection between hox gene expression and the type of vertebrae formed?

Dorsal-Ventral Axis Formation

What is the connection between a-v pole and d-v axis?

Left-Right Axis

What appears to be responsible for specifying the left-right axis?

Early Development of Vertebrates Fish, Birds, and Mammals.

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