Development: Anterior-Posterior Patterning

Question 1

Molecule responsible for neurulation

Answer 1

Retinoic acid (RA)

Question 2

What does retinoic acid turn on at specific times and places?

Answer 2

• Sonic Hedgehog (SHH)
• Homeobox genes (HOX)

Question 3

Peptide signal important for the axis of neural tube development

Answer 3

Sonic Hedgehog (SHH)

Question 4

Genes involved in dorsal differentiation

Answer 4

Bone Morphogenic Proteins (BMP)

Question 5

Genes thought to be masters organizers of body segments

Answer 5

Homeobox genes (HOX)

Question 6

This needs to be inhibited in order to transform ectoderm from a epidermal fate to a neural fate

Answer 6

Bone Morphogenic Proteins

Question 7

At what day is most of the neurotube closed?

Answer 7

22

Question 8

At what day does the anterior portion of the neurotube close?

Answer 8

25

Question 9

At what day does the posterior portion of the neurotube close?

Answer 9

27

Question 10

Failure of the anterior portion of the neurotube closing

Answer 10

Anencephaly

Question 11

Failure of the posterior portion of the neurotube closing

Answer 11

Spina bifida

Question 12

More mild form of spina bifida

Answer 12

Occulta

Question 13

More serious form of spina bifida

Answer 13

Cystica

Question 14

What may spina bifida cystica cause?

Answer 14

• Paralysis
• Hydrocephalus

Question 15

Mineral that can reduce incidences of neural tube defects by 70%

Answer 15

Folic acid (4mg/day)

Question 16

Medication that increases the risk of neural tube defects?

Answer 16

Anticonvulsants

Question 17

What does most of the CNS arise from?

Answer 17

Neural tube

Question 18

What does most of the PNS arise from?

Answer 18

Neural crest

Question 19

By which day do the 3 vesicles form the future brain?

Answer 19

24