Molecular Embryology and Trunk Development - Reverse Flashcards Preview

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Flashcards in Molecular Embryology and Trunk Development - Reverse Deck (81)
1

High BMP4 and low Shh

surface ectoderm induced by

2

Intermediate BMP4 and Shh

neural crest induced by

3

low BMP4 and high Shh

neural tube induced by

4

specifies neural crest cell fate/promotes cells migration

SNAIL/SLUG

5

BMP4 concentration gradient

specification of the mesoderm

6

high BMP4

lateral plate mesoderm (lpm) IB

7

intermediate BMP4

intermediate mesoderm(im) IB

8

low BMP4, differentiates into somites

paraxial mesoderm (pm) IB

9

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

Hox proteins

10

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

homeobox genes

11

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

Somite development order

12

located where RA signal overpowers FGF8 signal

someite differentiation front

13

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

RA

14

from notocord induces sclerotome

Shh (effect on mesoderm)

15

from neural tube/surface ectoderm induces myotome

Wnt (effect on mesoderm)

16

from neural tube induces dermatome

NT-3 (effect on mesoderm)

17

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

myotome

18

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

dermatome

19

SHH -> Pax1

scleratome (signal + TF)

20

WNT -> MRF (Myf5 + MoyD)

myotome (signal + TF)

21

NT-3 -> Pax3

dermatome (signal + TF)

22

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

NODAL

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.

Pitx2

24

BMP4 from ectoderm promoting expression of Pax 3 & Pax 7

dorsalization

25

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

ventralization

26

promotes migration of neural crest cells

SLUG

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)

BMP4

28

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

left-right asymettry

29

releases NODAL. Where invagination occurs.

primitive node

30

expression at primitive streak controls cell migration

FGF8

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.

somitomeres

32

differentiate into axial skeleton. cells express PAX1.

sclerotome

33

induces sclerotome development

SHH and Noggin expression

34

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

hypaxial division

35

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

epaxial division

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.

ossification

37

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

intervertebral discs

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.

resegmentation

39

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

intersegmental arteries

40

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

spinal nerves

41

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

myotomes

42

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

ribs

43

derived from parietal layer of lateral plate mesoderm.

sternum

44

right and left halves do not fuse appropriately.

cleft sternum

45

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

accessory, forked, or fused ribs

46

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

hemivertebra

47

fracture of pars interarticularis due to congenital developmental defects or trauma

spondylolysis

48

dislocation between adjacent vertebrae subsequent to spondylolysis.

spondylolisthesis

49

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

failure of neuropores to close results in:

50

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

rachischisis

51

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

folic acid supplement reason

52

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

mesoderm differentiation

53

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

SHH

54

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

epaxial derivatives

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.

Day 1

56

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

Week 1

57

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

Week 2

58

ectopic pregnancy, placenta previa, molar pregnancy, choriocarcinoma.

Week 2 complications

59

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

Weeks 3-4

60

forms urogenital system

Intermediate mesoderm

61

forms connective tissue of body wall and limbs

parietal layer of lateral plate mesoderm

62

GI/respiratory organs exxcept epithelial lining

visceral layer of lateral plate mesoderm

63

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

Weeks 4-8

64

chondrification centers for vertebral column develop

week 6

65

primary ossification centers for vertebral column develop

week 7

66

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

week 8

67

produces floating ribs

hox9

68

prevents rib formation

hox 10

69

from parietal layer of lateral plate mesoderm

sternum formation

70

sacralization of vertebrae

Hox11

71

rostral neuropore doesn't close

Anencephaly

72

causal neuropore doesn't close

spina bifida

73

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

Caudal dysgenesis

74

form of CD, mermaid syndrome

Sirenomelia

75

Loss of function: ribcages with all ribs attacted to sternum

Mutation of Hox9

76

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

Mutation of Hox10

77

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

Mutation of Hox 11

78

fracture of pars interarticularis

Spondylolysis

79

Hox11 gain of function mutation at L5

Sacralization of L5 vertebra

80

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

Weeks 9+ (fetal period)

81

weeks 24 - 28

Sound and light recognition