V

D

Latent Dorsalizing Factors

The Point of Fertilization Orients the D/V Axis of the Frog

ß-Catenin Acts as a Morphogen to Pattern the D/V Axis

Gastrulation: From Embryo to Tadpole

Cleavage: From Fertilized Egg to Blastula

Gastrulation of A Frog Embryo

Evolutionary Conservation of Hox Expression Patterns

Evolutionary Conservation of Hox Gene Function

Evolutionary Conservation of Hox Gene Function

Wild-Type Antenna

Antenna Transformed by Mouse Hox Gene

Wild-Type Leg

Claw Claw

Neural Induction by the Spemann Organizer

The Mangold Spemann Experiment

Chordin Versus BMP Expression in Frog Embryo

Allow Cells toDifferentiate

Animal Caps

Reaggregate Cells

Incubate

Dissociate Cells

Allow Cells toDifferentiate

Animal Caps

Reaggregate Cells

Incubate

Dissociate Cells

+ BMP4+ BMP4+ Chordin

Allow Cells toDifferentiate

Animal Caps

Reaggregate Cells

Incubate

Dissociate Cells

+ BMP4

Allow Cells toDifferentiate

Animal Caps

Reaggregate Cells

Incubate

Dissociate Cells

+ BMP4+ BMP4+ Chordin

Allow Cells toDifferentiate

Animal Caps

Reaggregate Cells

Dissociate Cells

Incubate + BMP4+ BMP4+ Chordin

Evolutionary Conservation of BMP Signaling

Evolutionary Conservation of BMP Signaling

Inverted-brateHypothesis

Evolutionary Conservation of Neural Induction