Development of Chicken Embryo

Name: Score: _____________

Icban, Shahad O. Date: February 2, 2014

Jimenez, Ivy O.

Professor: Maam Olgga Hara

Worksheet 10

Development of Chicken Embryo

1. Compare the process of embryonic development of the chicken and the frog.

Table 10.1 Comparison of the embryonic development of the chicken and the frog.

Basis of Comparison Chicken Frog

Early development Cells of the blastoderm divide and as they do, they pile up producing a multicellular layer on top of the yolk. With time, the layer of cells on top of the yolk split, forming two layers separated by a cavity called the blastocoel.

Cells in the animal pole begin dividing more rapidly than those in the vegetal pole and thus become smaller and more numerous. No growth.

Late Development Primitive streak produced; brain, neural structures, and somites are formed. They will form part of the backbone and will also contribute cells for the formation of limbs. Some of the ectoderm folds in on itself and pinches off, forming a hollow tube called the neural tube. The neural tube then differentiates into the brain and spinal cord.

Invagination of cells in the region of the embryo once occupied by the middle of the gray crescent which produces blastopore that will be the future anus, and Spemann organizer. Germ layers are formed.

Others Many new organs are visible including parts of brain, eye, heart, ear, limb buds, and allantois. Yolk is large, gone when hatched.

Although the various layers of cells have definite and different fates in store for them, these are not readily apparent in their structure. However, the cells of the embryo take on the specialized structures and

functions that they have in the tadpole, forming neurons, blood cells, muscle cells, epithelial cells, etc. Yolk still present when hatched.

Analyze table 10. 1

Chick eggs are larger than frog eggs. Frog eggs have a jelly-like covering, while chick eggs have a

hard shell and must be fertilized internally. Both embryos have gills in the beginning, and have yolk sacs

that nourish the embryo until it is able to feed independently.

2. Label the different structures of the whole mount of the chicken embryo at 24, 33, 48 and 72.

24 hour chicken embryo (40x)

1. Anterior neuropore

10. Primitive groove

8. Somite

2. Prosencephalon

4. Rhombencephalon

3. Mesencephalon

9. Area pellucida

7. Notocord

11. Neural plate

5. Vitelline membrane

12. Primitive streak

6. Neural fold

33 hour chicken embryo (40x)

48 hour chicken embryo (40x)

1. Proaminion

3. Notocord

4. Vitelline vein

2. Diencephalon

6. Prosencephalon

8. Mesencephalon

5. Sinoarterial region of the heart

9. Metencephalon

10. Ventricle of the heart

1. Metencephalon

6. Tail bud

14. Spinal cord

5. Somite

4. Vitelline artery

13. Ventricle of heart

7. Mesencephalon

9. Diencephalon

11. Telencephalon

3. Brachial arches

2. Otic vesicle

10. Optic cup + lens

12. Cranial intestinal portal

8. Brachial groove

7. Optic stalk and vesicle

72 hour chicken embryo

8. Metencephalon 2. Auditory vesicle

4. Brachial arch 3. Brachial groove

12. Diencephalon

7. Ventricle

13. Pineal gland

6. Conotruncus

1. Ganglion VII-VIII

11. Choroid fissure

14. Telencephalon

9. Mesencephalon

10. Myelencephalon

5. Truncus arteriosus

3. Label the different structures of the serial transverse section of the chicken embryo at 24, 33,

48, 72 and 96 hours of incubation viewed at LPO.

24 hour chicken embryo

Section through the pharynx (400x)

Section through the neural tube (400x)

1. Neural tube

3. Foregut

5. Coelom

4. Pharyngeal

membrane

6. Subcephalic pocket

2. Mesenchyme

7. Neural fold

9. Mesenchyme

8. Ectoderm 10. Neural tube

12. Coelom

11. Somatic mesoderm 13. Splanchnic mesoderm

Section through the somite (400x)

33 hour chicken embryo

Section through the pharynx and ventral aorta (400x)

14. Neural fold

15. Somite

1. Neural crest cells 2. Notocord

3. Mesencephalon

5. Foregut 6. Dorsal aorta

7. Ventral aorta 4. Coelom

Section through the open gut (400x)

Section through the heart (400x)

9. Ectoderm

11. Endoderm of gut

13. Lateral body fold

10. Somatic mesoderm

8. Neural crest cells

14. Foregut

16. Endocardium

17. Epi-myocardium

15. Dorsal aorta

12. Vitelline vein

48 hour chicken embryo section through the stomach, heart and eye (400x)

48 hour chicken embryo section through the midgut, vitelline veins and mesonephros (100x)

1. Spinal cord

9. Notochord

3. Dorsal aorta

2. Superior ganglion

13. Optic cup

15. Lens

14. Opticoel 8. Diencephalon

7. Portion of telencephalon

4. Pharynx

5. Aortic arch

6. Extraembryonic coelom 11. Epibrachialplacode

12. Ventral mesentery

10. Anterior cardial vein

1. Chorion

2. Yolk sac 3. Intraembryonic coelom

4. Vitelline vein

5. Dorsal aorta

7. Spinal cord

8. Somite

9. Mesonephric duct rudiment

10. Amnion

6. Anterior intestinal portal

72 hour chicken embryo section through the brachial arches (400x)

72 hour chicken embryo section through the Rathkes pouch

1. Spinal cord

2. Dorsal aorta 7. Notochord

3. Pharyngeal pouch III

4. Brachial arch III

5. Brachial arch II

6. Mandibular process

12. Metencephalon 11. Precardinal vein

8. Dorsal aorta

10. Pre-oral gut

12. Mesencephalon

10. Infundibulum

3. Precardinal vein

2. Notochord

6. Mandibular process

5. Brachial arch II

8. Pharynx

7. Dorsal aorta

9. Stomodeum

1. Dermomyotome

11. Precardinal vein

9. Third aortic arch

4. Third aortic arch

72 hour chicken embryo section through the eye and heart (40x)

12. Diencephalon

11. Sensory retina

7. Aortic sac

8. Mesoesophagus

9. Pharynx

10. Common cardinal vein 5. Atrium

6. Endocardium of conotruncus

4. Lung bud

3. Common cardinal vein

2. Post cardinal vein

96 chicken embryo section through the auditory vesicle

2. Anterior cardinal vein

1. Dermomyotome

3. Auditory vesicle

1. Neural tube

7. Diencephalon

8. Metencephalon

5. Ganglion V

4. Auditory nerve

6. Amnion

96 hour embryo through the esophagus, lung bud, heart and eye (40x)

8. Myotome

9. Posterior cardinal vein

10. Lung bud

11. Esophagus

12. Dorsal mesocardium

13. Lens vesicle

14. Retina

2. Pleural cavity

1. Descending aorta

3. Pericardial cavity

4. Atrium

5. Choroid fissure

6. Optic stalk

7. Diencephalon

96 hour embryo through the mesonephros, limb bud, and telencephalon (40x)

Conclusion

When the egg is laid, some embryonic development has occurred and usually stops until

proper cell environmental conditions are established for incubation to resume. At first, all the

cells are alike, but as the embryo develops, cell differences are observed. Some cells may

become vital organs; others become a wing or leg. From the primitive streak, the head and

backbone of the embryo develop. A precursor of the digestive tract forms; blood islands appear

and will develop later into the vascular or blood system; and the eye begins. Other organs such

as brain, heart, ear, limb buds, and allantois are also then formed.

References

Comparing Eggs and Embryos. Retrieved on 1 Feb 2015 from

http://www.lamer.lsu.edu/pdfs/NFC_10Embryos.pdf

Developmental Biology. Retrieved on 1 Feb 2015 from

http://www.uic.edu/classes/bios/bios100/labs/develop.htm

Frog Embryology. Retrieved on 1 Feb 2015 from

http://users.rcn.com/jkimball.ma.ultranet/BiologyPages/F/FrogEmbryology.html

7. Spinal ganglion

8. Posterior cardinal vein

9. Anterior cardinal vein

10. Esophagus

11. Stomach

12. Hindgut

1. Spinal cord

2. Notochord

3. Dorsal aorta

4. Pharynx

5. Sinus venosus

6. Telencephalon