Molecular Embryology and Trunk Development - Reverse

Question 1

High BMP4 and low Shh

Answer 1

surface ectoderm induced by

Question 2

Intermediate BMP4 and Shh

Answer 2

neural crest induced by

Question 3

low BMP4 and high Shh

Answer 3

neural tube induced by

Question 4

specifies neural crest cell fate/promotes cells migration

Answer 4

SNAIL/SLUG

Question 5

BMP4 concentration gradient

Answer 5

specification of the mesoderm

Question 6

high BMP4

Answer 6

lateral plate mesoderm (lpm) IB

Question 7

intermediate BMP4

Answer 7

intermediate mesoderm(im) IB

Question 8

low BMP4, differentiates into somites

Answer 8

paraxial mesoderm (pm) IB

Question 9

transcription factors responsible for craniocaudal body segmentation, e.g. Hoxa1, Hoxd13

Answer 9

Hox proteins

Question 10

4 chromosomes, 13 gene clusters that code for Hox proteins. Provide spatial/temporal colinearity of gene expression & development

Answer 10

homeobox genes

Question 11

Cranial to caudal. RA (cranial) promotes Hox gene expression. FGF8 (caudal) inhibits Hox.

Answer 11

Somite development order

Question 12

located where RA signal overpowers FGF8 signal

Answer 12

someite differentiation front

Question 13

induces paraxial mesoderm to form somites via Hox. intercellular signaling molecule that guides development of the posterior portion of the embryo.

Answer 13

RA

Question 14

from notocord induces sclerotome

Answer 14

Shh (effect on mesoderm)

Question 15

from neural tube/surface ectoderm induces myotome

Answer 15

Wnt (effect on mesoderm)

Question 16

from neural tube induces dermatome

Answer 16

NT-3 (effect on mesoderm)

Question 17

part of a somite that forms the muscles of the animal. cells express MyoD or Myf5.

Answer 17

myotome

Question 18

differentiate into dermis. the dorsal portion of the paraxial mesoderm somite which gives rise to dermis.

Answer 18

dermatome

Question 19

SHH -> Pax1

Answer 19

scleratome (signal + TF)

Question 20

WNT -> MRF (Myf5 + MoyD)

Answer 20

myotome (signal + TF)

Question 21

NT-3 -> Pax3

Answer 21

dermatome (signal + TF)

Question 22

a secretory protein that induces lateral plate mesoderm to form left-side structures by promoting expression of Pitx2.

Answer 22

NODAL

Question 23

responsible for the establishment of the left-right axis, the asymmetrical development of the heart, lungs, and spleen, twisting of the gut and stomach, as well as the development of the eyes. locally expressed in the left lateral mesoderm, tubular heart, and early gut which leads to the asymmetrical development of organs and looping of the gut.

Answer 23

Pitx2

Question 24

BMP4 from ectoderm promoting expression of Pax 3 & Pax 7

Answer 24

dorsalization

Question 25

Shh from the notocord antagonizes BMP4 (represses Pax 3 & Pax 7)

Answer 25

ventralization

Question 26

promotes migration of neural crest cells

Answer 26

SLUG

Question 27

signaling molecule secreted by the lateral plate mesoderm required for the early differentiation of the embryo and establishing of a dorsal-ventral axis. It is secreted from the dorsal portion of the notochord, and acts in concert with sonic hedgehog (released from the ventral portion of the notochord) to establish a dorsal-ventral axis for the differentiation of later structures as well as inducing posterior neural tube (sensory)

Answer 27

BMP4

Question 28

FGF8 cause cilia that preferentially sweep toward the left sidethat activates NODAL which induces LPM to promote Pitx2 induced left side development.

Answer 28

left-right asymettry

Question 29

releases NODAL. Where invagination occurs.

Answer 29

primitive node

Question 30

expression at primitive streak controls cell migration

Answer 30

FGF8

Question 31

form skeletal muscle in head, don't dorm bony structures that come from somites. form on sides of cranial neural tube. do not segregate into sclerotome, dermatome, and myotome.

Answer 31

somitomeres

Question 32

differentiate into axial skeleton. cells express PAX1.

Answer 32

sclerotome

Question 33

induces sclerotome development

Answer 33

SHH and Noggin expression

Question 34

myotome posterolateral origin. MyoD expression. body wall and limb muscles. anterior primary rami.

Answer 34

hypaxial division

Question 35

myotome posteromedial origin. Myf5 expression. intrinsic back muscles. posterior primary rami

Answer 35

epaxial division

Question 36

begins in utero by 7 weeks. primary centers form by 7 weeks and are active until age 6. secondary ossification is complete around 25 years of age. at birth vertebrae consist of three bony parts united by cartilage.

Answer 36

ossification

Question 37

form from notochord and mesenchyme of somites. notochord forms nucleus pulposus. mesenchyme forms anulus fibrosus

Answer 37

intervertebral discs

Question 38

occurs as each vertebra forms from the fusion of the caudal half of the sclerotome of one somite and the cranial half of the sclerotome of the subjacent somite. somites surround neural tube and notochord.

Answer 38

resegmentation

Question 39

visceral mesoderm, initally between somites and finish at mid-vertebrae.

Answer 39

intersegmental arteries

Question 40

outgrowth of neural tube, initially at mid-somite, finish between vertebrae.

Answer 40

spinal nerves

Question 41

come from paraxial mesoderm, initially within somite and finish to span vertebrae, allowing for movement of the vertebral column)

Answer 41

myotomes

Question 42

bony part derived from sclerotome portion of paraxial mesoderm. cartilaginous part derived from sclerotome cells that migrated.

Answer 42

ribs

Question 43

derived from parietal layer of lateral plate mesoderm.

Answer 43

sternum

Question 44

right and left halves do not fuse appropriately.

Answer 44

cleft sternum

Question 45

loss of function mutation of various Hox genes, can lead to accessory cervical or lumbar ribs.

Answer 45

accessory, forked, or fused ribs

Question 46

malformations of the spine resulting in wedge-shaped vertebrae that can cause an angle in the spine (such as kyphosis, scoliosis, and lordosis).

Answer 46

hemivertebra

Question 47

fracture of pars interarticularis due to congenital developmental defects or trauma

Answer 47

spondylolysis

Question 48

dislocation between adjacent vertebrae subsequent to spondylolysis.

Answer 48

spondylolisthesis

Question 49

ancephaly, spina bifida, rachischisis. Can be indicated pre-birth with a-feroprotin increase inmaternal serum tests.

Answer 49

failure of neuropores to close results in:

Question 50

severe caudal failure, in which neural tissue is exposed and often becomes necrotic)

Answer 50

rachischisis

Question 51

intake prior to and during pregnancy can decrease incidence of neural tube defects by as much as 70%

Answer 51

folic acid supplement reason

Question 52

lateral plate, intermediate, paraxial. Driven by BMP4 concentration gradient.

Answer 52

mesoderm differentiation

Question 53

induces ectoderm to form neuroectoderm which undergoes neurulation to form neural tube and neural crest, then induces anterior neural tube (motor).

Answer 53

SHH

Question 54

non-migratory myoblasts, i.e. back muscles.

Answer 54

epaxial derivatives

Question 55

Spermreach oocyte, pass through CR. Acrosome reaction (male), Zona reaction (female). Sperm fuses with ocyte membrane, oocyte completes M2. Pronuclei fuse to from single diploid nucleus.

Answer 55

Day 1

Question 56

Cleavage, compaction (day 4), cavitation, hatching, implantation (day 6)

Answer 56

Week 1

Question 57

uteroplacental circulation, trophoblast differentiation (cytotrophoblast and syncytiotrophoblast.), bilaminar disc formation, chorionic cavity formation, hcG detectable day 8.

Answer 57

Week 2

Question 58

ectopic pregnancy, placenta previa, molar pregnancy, choriocarcinoma.

Answer 58

Week 2 complications

Question 59

Gastrulation, neurulation, NODAL expression, FGF8 expression, hypoblast displaced, body axes established, lateral body folding.

Answer 59

Weeks 3-4

Question 60

forms urogenital system

Answer 60

Intermediate mesoderm

Question 61

forms connective tissue of body wall and limbs

Answer 61

parietal layer of lateral plate mesoderm

Question 62

GI/respiratory organs exxcept epithelial lining

Answer 62

visceral layer of lateral plate mesoderm

Question 63

somites differentiate (wk 4), myotome differentiation (wk 5), resegmentation (wk 5), organogenesis

Answer 63

Weeks 4-8

Question 64

chondrification centers for vertebral column develop

Answer 64

week 6

Question 65

primary ossification centers for vertebral column develop

Answer 65

week 7

Question 66

ribs form (sclerotome), tail regresses, limbs rotate/enlongate, digits and face develop,

Answer 66

week 8

Question 67

produces floating ribs

Answer 67

hox9

Question 68

prevents rib formation

Answer 68

hox 10

Question 69

from parietal layer of lateral plate mesoderm

Answer 69

sternum formation

Question 70

sacralization of vertebrae

Answer 70

Hox11

Question 71

rostral neuropore doesn't close

Answer 71

Anencephaly

Question 72

causal neuropore doesn't close

Answer 72

spina bifida

Question 73

malformed pelvis, underdeveloped lower limbs, 250X more in pregestational diabetics

Answer 73

Caudal dysgenesis

Question 74

form of CD, mermaid syndrome

Answer 74

Sirenomelia

Question 75

Loss of function: ribcages with all ribs attacted to sternum

Answer 75

Mutation of Hox9

Question 76

Loss of function: lumbar and sacral vertebrae with ribs. Gain of function: Thoracic vertebrae without ribs

Answer 76

Mutation of Hox10

Question 77

LoF: Sacral vertevrae that donot fuse. GoF: vertebrae at various levels fusing

Answer 77

Mutation of Hox 11

Question 78

fracture of pars interarticularis

Answer 78

Spondylolysis

Question 79

Hox11 gain of function mutation at L5

Answer 79

Sacralization of L5 vertebra

Question 80

bone ossification centers (wk 12), ext genetalia visible (wk 12), swallowing and urine formation (wk 10), respiratory movements (wk 15)

Answer 80

Weeks 9+ (fetal period)

Question 81

weeks 24 - 28

Answer 81

Sound and light recognition