The Body Plan Flashcards
(20 cards)
What is the body plan?
The basic spatial organisation of body axes and tissues
What are the three axes?
Anterior-Posterior, Dorsal-Ventral, Left-Right
What sets the A-P axis?
Primitive streak formation
What signals posterior identity?
FGF and Wnt
What signals anterior identity?
Retinoic acid and AVE signals
What inhibits BMP for dorsal identity?
Chordin, Noggin, Follistatin
What forms the dorsal neural tube?
BMP inhibition in ectoderm
What forms ventral structures like the gut?
High BMP activity
What organises L-R asymmetry?
Cilia-driven flow at the node
What genes act on the left side?
Nodal, Lefty, Pitx2
What happens if L-R asymmetry fails?
Situs inverses or heterotaxy
What defines segmental identity?
Hox gene expression
What secretes SHH in the midline?
The notochord
What does the AVE do?
Promotes head development by inhibiting Wnt
What is the node equivalent in amphibians?
Spemann organiser
What defines dorsal mesoderm fate?
High Nodal + low BMP
What germ layer becomes skin and CNS?
Ectoderm
What germ layer becomes heart and muscle?
Mesoderm
What layer becomes gut and lungs?
Endoderm
What is a fate map?
A diagram showing which embryonic regions give rise to which tissues
