endoderm

Question 1

Embryonic origin of endoderm

Answer 1

The cells of the hypoblast, which is the innermost germ layer

Question 2

Markers of pluripotency in epiblast

Answer 2

Nanog+/Oct4+

Question 3

Markers of multipotency in hypoblast

Answer 3

Gata6+/Sox17+

Question 4

Position of endoderm precursors in invertebrates

Answer 4

internally located

Question 5

Position of endoderm precursors in sea urchin

Answer 5

near primitive gut/archenteron

Question 6

Position of endoderm precursors in Drosophila

Answer 6

midgut result of movement

Question 7

Position of endoderm precursors in mouse

Answer 7

near primitive streak

Question 8

Position of endoderm precursors in chick

Answer 8

posterior part

Question 9

Embryonic Origin of the Endoderm: Sea urchin

Answer 9

Ectoderm
Endoderm
Mesoderm

Question 10

Embryonic Origin of the Endoderm: Xenopus

Answer 10

Ectoderm
Mesoderm
Endoderm

Question 11

Embryonic Origin of the Endoderm: Zebrafish

Answer 11

Ectoderm
Mesoderm
Mesendoderm
Yolk

Question 12

Embryonic Origin of the Endoderm: Mouse

Answer 12

Shaped like a cap
Ectoderm outside
Mesoderm and endoderm goes inside

Question 13

The mesendoderm becomes mesoderm in the presence of ________

Answer 13

Nkx2.5

Question 14

The mesendoderm becomes endoderm in the presence of ________

Answer 14

HNF

Question 15

Important in the specification and differentiation of the mesendoderm

Answer 15

GATA456

Question 16

Major functions of the definitive endoderm

Answer 16

INDUCE formation of mesoderm/mesodermal organs
CONSTRUCT linings of digestive and respiratory tubes

Question 17

Endoderm-Mesoderm Interaction

Answer 17

1. Shh in endo
2. Reception of Shh protein in meso
3. Hox gene expression in meso
4. Specification of meso
5. BMPs, FGFs made by meso
6. Reception of paracrine signals by endo
7. Specification and differentiation of endo
8. Paracrine factors
9. Differentiation of meso

Question 18

Stages of endoderm development

Answer 18

1. Endoderm formation
2. Tube formation
3. Bud formation
4. Organ-specific cyto-differentiation

Question 19

Regional expression of TFs in endoderm

In the chick, it appears to be

Answer 19

Regionally specified even before it forms the tube (1.5 d)

Question 20

Timeline of endoderm organ formation in mouse

Answer 20

E7.5 (Endoderm formation)
- Gastrulation
- Mesendoderm and ectoderm
- Mesoderm and endoderm

E8.5 (Endoderm patterning)
- Endoderm becomes foregut, midgut, and hindgut

(Organ specification)

E9.5 (Organ buds)

(Proliferation differentiation)

Question 21

Differential TF gene expression in the chick endoderm

Answer 21

• one-dimensional patterning
• expression of Hox-cluster genes
• Expression of ParaHox-cluster genes

Question 22

Patterning of the gut tube

Answer 22

Anterior part - Liver
Median part - Dorsal pancreas
Posterior part - Hindgut

Question 23

TFs responsible for esophagus

Answer 23

Hoxa-3, Hoxb-4, Hoxa-2, Six2/Sox2

Question 24

TFs responsible for stomach

Answer 24

Hoxc-5

Question 25

TFs responsible for pancreas

Answer 25

Pdx-1

Question 26

TFs responsible for liver

Answer 26

Hex1

Question 27

TFs responsible for small intestine

Answer 27

Hoxc-9, Hoxb-8, Hoxc-6, Hoxb-9

Question 28

TFs responsible for ceca/cecum

Answer 28

Hoxd-13, Hoxa-13, CdxA

Question 29

TFs in the early gut tube (foregut)

Answer 29

- TTF1/Nkx2.1 - Nkx2.6 - Pax8 - Pax9 - Hex1 - Hoxb1

Question 30

TFs in the early gut tube (fore/midgut)

Answer 30

- Pdx1 - Pax4 - Pax6 - Nkx2.2 - Isl-1 - NeuroD

Question 31

TFs in the early gut tube (mid/hindgut)

Answer 31

- cdx2 - Hoxd genes

Question 32

Which transcription factor regulates patterning of intestinal epithelium

Answer 32

Cdx2

Question 33

Derivatives of the Endoderm

Answer 33

- Digestive tube, (esophagus, stomach, intestine) liver, pancreas and gall bladder - Respiratory tube pharynx (tonsils,thyroid,thymus and parathyroid) trachea bronchi, lungs

Question 34

Derivatives of the foregut

Answer 34

1. Pharynx and its derivatives 2. The lower respiratory tract 3. The esophagus 4. The stomach 5. The duodenum, proximal to the ampulla of Vater 6. The liver 7. The pancreas 8. The biliary apparatus

Question 35

Derivatives of the midgut

Answer 35

1. the small intestine (except for the proximal duodenum) 2. the cecum 3. the appendix 4. the ascending colon 5. the right 1/2 to 2/3 of the proximal part of the transverse colon

Question 36

Derivatives of the hindgut

Answer 36

1. cloaca 2. urogenital sinus 3. urinary bladder 4. ampulla of Vater 5. distal one-third of the transverse colon 6. descending colon

Question 37

GERM LAYER ORIGIN OF GI TRACT (Endoderm)

Answer 37

Source of the epithelial lining of the gastrointestinal tract, liver, gallbladder, pancreas.

Question 38

GERM LAYER ORIGIN OF GI TRACT (Mesoderm)

Answer 38

Connective tissue, including the wall of the gut tube and the smooth muscle

Question 39

GERM LAYER ORIGIN OF GI TRACT (Ectoderm)

Answer 39

NCC is the source of the PNS, including the neurons of the GI tract (enteric nervous system)