Exam 3 Study Guide
What germ layer are neural crest cells derived from?
What are some tissues derived from Neural crest cells?
Be familiar with characteristics of neural crest cells.
Be familiar with how neural crest cells are able to give rise to different cell types (eg they
are mulitpotent, the migrate to new positions)
EMT and neural crest cells
How do we determine what cell/tissues are derived from neural crest cells experimentally?
Be generally familiar with neural crest cells with respect to pigmentation and craniofacial
Paraxial Mesoderm (main focus is on somites)
What tissues are derived from Paraxial Mesoderm?
What gene class controls patterning of the somites along the A-P axis?
What are the characteristics of somites?
Be familiar with some tissues derived from somites and how somites are patterned.
Be familiar with the processes of endochondrial ossification- what types of bones develop
Be familiar with development of the vertebrae.
Intermediate Mesoderm (urogenital system, main focus is on Kidney)
Be familiar with progression of kidney development, what stages are transient and where
does the adult kidney come from?
Be familiar with specification of the kidney and the experiments that demonstrated this.
Be familiar with the reciprocal inductive interactions during kidney development and the
basic steps of kidney development- you do not need to memorize the specific molecules
Lateral Plate Mesoderm
What are some tissues derived from the lateral plate mesoderm?
Be familiar with heart development: heart tube, looping and formation of the chambers are
the main topics.
What are some tissues that are derived from endoderm?
The main focus is on the digestive system
How is the digestive tube patterned along the A-P axis, generally?
Know that the different organs that form from the digestive tube and the pattern of the
digestive tube is also due to interactions between the endoderm and lateral plate
Know that the lungs form by branching off of the digestive tube.
How are forelimbs distinguished from hindlimbs?
Know generally how limb buds are induced (you don’t have to memorize the specific
molecules, but you should understand conceptually how different molecules function in
What is the AER? What axis is it important for patterning?
Understand the role of the AER and the limb mesenchyme in P-D axis patterning and the
experiments used to discover these roles.
What is the progress zone?
What is the ZPA and how does it pattern the A-P axis of the limb? Understand experiments
that demonstrated the function of the ZPA and Shh in limb patterning.
How does Shh pattern the limb?
What role does apoptosis play in limb development? How is this different in different
How do limbs continue to grow after they are patterned?
How do limbs stop growing when the animal reaches its adult size?
Be familiar with disease that result from misregulation of bone growth.
You sould know the role of FGF signaling by the AER and the role of SHH signaling by the
Understand how the Retinoic Acid and FGF gradients pattern the P-D limb axis.
How do Hox genes pattern the P-D axis of the limb? What happens to a limb if you delete
one of the Hox genes?
Post embryonic development: Metamorphosis and Regeneration (aging will not be
on the final)
What are the 4 ways that regeneration occurs, know an example of each
How do planarians reproduce?
What are neoblasts and what is their role in regeneration? What experiments
demonstrated that regenerated tissues come from neoblasts?
What is the wound epithelium? What is the blastema?
Understand the role of BMP (TGFb) in Dorsal Ventral polarity.
What is the role of Wnt and b-catenin in planarian regeneration? How can you get an
animal that regenerates two heads?
How do salamanders regenerate their limbs?
Understand the 3 basic requirements for limb regeneration.
What is the wound epithelium, blastema, and AEC? What are their roles in limb
Understand experiments that lead to the understanding of lineage restriction of blastema
cells in amphibians.
How do hydras regenerate?
How was the head activator defined experimentally?
What tissue can act as an organizer in hydra?
How is budding restricted to the center of the body in hydra?
What is the role of wnt and b-catenin in hydra regeneration?
How does the mammalian liver regenerate?
Know what direct development and indirect development are and know examples of
animals that undergo each of these types of development.
Know the difference between primary and secondary larva and know some examples.
Know some examples of structures that change during amphibian metamorphosis.
How is metamorphosis triggered in amphibians? In what ways do tissues respond? Know
some of the examples discussed.
Is the response of tissues to thyroid hormones location or tissue specific in amphibians?
What are the three different ways that insects undergo metamorphosis (you wont need to
recall these terms, but be able to recognize them if you see them).
Generally, how does drosophila undergo metamorphosis?
What are imaginal cells? How do they function in metamorphosis?
Understand patterning of the wing imaginal disc.
You should understand the role of hh,
engrailed, dpp in A-P patterning.
Remember that metamorphosis is hormonally controlled in insects and how larval molts
and the pupal molt differ.
Understand the concept of aging as a part of an organisms developmental program.
Know the role of DNA repair, p53, telomeres, Insulin signaling and misregulation of DNA
methylation in aging.
What are some of the different mechanisms that animals use to determine sex?
Mammalian Sex determination: Be familiar with chromosomal sex determination in
mammals, primary sex determination, secondary sex determination, the role of SRY.
Where does the gonad develop from? (what germ layer?)
You don’t need to memorize all the different cell and tissue types of the male and female
Understand that the ovary and testis develop from a biopotential gonad and that sex
determination directs whether the gonad develops as an ovary or testis
Understand how SRY controls sex determination.
Know SRY, Sox9, Wnt4, and B-catenin.
Secondary sex determination: general concepts.
Know the hormones that are involved.
Know some structures that are affected by secondary sex determination (especially the
Sex Determination in Drosophila: how does XY chromosomal sex determination in
drosophila differ from mammalian XY chromosomal sex determination?
Know that there are genes on the X that regulate Sxl in a dose-dependant way.
Know Sxl and Dsx and how they control male vs female fate.
What is a gynandomorph (generally)? What does it tell you about how sex is determined?
Sex Determination in Birds: How is chromosomal sex determination similar/different to
chromosomal sex determination in mammals and drosophila?
How does DMRT1 control sex determination in birds, what gene is it related to?
Environmental Sex Determination: What are some environmental factors that determine
*Experimental data should be understood conceptually.