1 mm

1. Chap 47 Animal development Preformation homunculus 1 mm

2. Development is determined by the zygote’s genome and molecules in the egg called cytoplasmic determinants Cell differentiation is the specialization of cells in structure and function Morphogenesis is the process by which an animal takes shape FertilizationCleavageGastrulationOrganogenesis

3. Fig. 47-3-1 Basal body(centriole) Spermhead Acrosome Jelly coat Vitelline layer Sperm-bindingreceptors Egg plasmamembrane

4. Fig. 47-3-2 Basal body(centriole) Spermhead Hydrolytic enzymes Acrosome Jelly coat Vitelline layer Sperm-bindingreceptors Egg plasmamembrane

5. Acrosomal reaction Fig. 47-3-3 Spermnucleus Acrosomalprocess Basal body(centriole) Actinfilament Spermhead Hydrolytic enzymes Acrosome Jelly coat Vitelline layer Sperm-bindingreceptors Egg plasmamembrane

6. Acrosomal reaction fast block to polyspermy Fig. 47-3-4 Sperm plasmamembrane Spermnucleus Acrosomalprocess Basal body(centriole) Actinfilament Spermhead Fusedplasmamembranes Hydrolytic enzymes Acrosome Jelly coat Vitelline layer Sperm-bindingreceptors Egg plasmamembrane

7. A fast block to polyspermy Acrosomal reaction Cortical reaction: a slow block to polyspermy Fig. 47-3-5 Sperm plasmamembrane Spermnucleus Fertilizationenvelope Acrosomalprocess Basal body(centriole) Actinfilament Spermhead Corticalgranule Fusedplasmamembranes Perivitellinespace Hydrolytic enzymes Acrosome Jelly coat Vitelline layer Sperm-bindingreceptors Egg plasmamembrane EGG CYTOPLASM

8. EXPERIMENT Ca2+ the formation of the fertilization envelope？ Fig. 47-4 25 sec 35 sec 1 min 10 sec afterfertilization 500 µm RESULTS 10 sec afterfertilization 20 sec 30 sec 1 sec beforefertilization 500 µm CONCLUSION Point ofspermnucleusentry Spreadingwave of Ca2+ Fertilizationenvelope

9. Fig. 47-4a EXPERIMENT 10 sec afterfertilization 25 sec 35 sec 1 min 500 µm

10. Fig. 47-4b RESULTS 10 sec afterfertilization 20 sec 30 sec 1 sec beforefertilization 500 µm

11. Fig. 47-4c CONCLUSION Point ofspermnucleusentry Spreadingwave of Ca2+ Fertilizationenvelope

12. Fertilization in mammals Zona pellucida Fig. 47-5 Follicle cell Cortical granules Spermnucleus Spermbasal body

13. Holoblastic cleavage meroblastic cleavage Cleavage Fig. 47-6 (a) Fertilized egg (b) Four-cell stage (c) Early blastula (d) Later blastula

14. (a) The three axes of the fully developed embryo Dorsal Right Fig. 47-7 Anterior Posterior Left Ventral (b) Establishing the axes Animal pole Firstcleavage Pigmentedcortex Point ofspermnucleusentry Animalhemisphere Futuredorsalside Vegetalhemisphere Graycrescent Vegetal pole (right—left) (Dorsal– ventral ) (anterior—posterior)

15. Fig. 47-7b-1 Animal pole Animalhemisphere Vegetalhemisphere Vegetal pole (b) Establishing the axes

16. 0.25 mm 0.25 mm Fig. 47-8-6 Blastocoel Animal pole Vegetalpole Zygote 2-cellstageforming 4-cellstageforming 8-cellstage Blastula(crosssection)

17. Gastrulation I (sea urchin) Future ectoderm Fig. 47-9-1 Future mesoderm Future endoderm Animalpole Blastocoel Mesenchymecells Vegetalplate Invagination Vegetalpole

18. Future ectoderm Fig. 47-9-2 Future mesoderm Future endoderm

19. Future ectoderm Fig. 47-9-3 Future mesoderm Future endoderm Filopodiapullingarchenterontip Archenteron

20. Future ectoderm Fig. 47-9-4 Future mesoderm Future endoderm Blastocoel Archenteron Blastopore

21. Future ectoderm Fig. 47-9-5 Future mesoderm Future endoderm Ectoderm Mouth Mesenchyme(mesodermforms futureskeleton) Digestive tube (endoderm) Anus (from blastopore)

22. Fig. 47-9-6 Key Future ectoderm Future mesoderm Future endoderm Archenteron Blastocoel Filopodiapullingarchenterontip Animalpole Blastocoel Archenteron Blastocoel Blastopore Mesenchymecells Ectoderm Vegetalplate Vegetalpole Mouth Mesenchymecells Mesenchyme(mesodermforms futureskeleton) Digestive tube (endoderm) Blastopore 50 µm Anus (from blastopore)

23. Gastrulation II (frog embryo) Fig. 47-10-1 SURFACE VIEW CROSS SECTION Animal pole Blastocoel Dorsal lipof blasto-pore Dorsal lipof blastopore Key Blastopore Future ectoderm Earlygastrula Future mesoderm Vegetal pole Future endoderm Invagination andInvolution

24. Fig. 47-10-2 CROSS SECTION SURFACE VIEW Blastocoelshrinking Archenteron Key Future ectoderm Future mesoderm Future endoderm

25. Fig. 47-10-3 CROSS SECTION SURFACE VIEW Ectoderm Mesoderm Blastocoelremnant Endoderm Archenteron Key Blastopore Future ectoderm Lategastrula Future mesoderm Yolk plug Blastopore Future endoderm

26. SURFACE VIEW CROSS SECTION Animal pole Blastocoel Fig. 47-10-4 Dorsal lipof blasto-pore Dorsal lipof blastopore Blastopore Earlygastrula Vegetal pole Blastocoelshrinking Archenteron Ectoderm Mesoderm Blastocoelremnant Endoderm Archenteron Key Blastopore Future ectoderm Lategastrula Future mesoderm Yolk plug Blastopore Future endoderm

27. Gastrulation III (a chick embryo)

28. Dorsal Fertilized egg Primitive streak Anterior Embryo Fig. 47-11 Left Right Yolk Posterior Ventral Primitive streak Epiblast Futureectoderm Blastocoel Endoderm Migratingcells(mesoderm) Hypoblast YOLK

29. Eye Somites Tail bud Neural folds Neural plate Neuralfold Fig. 47-12 SEM 1 mm 1 mm Neural crestcells Neural tube Neuralfold Neural plate Notochord Coelom Neural crestcells Somite Notochord Ectoderm Archenteron(digestivecavity) Outer layerof ectoderm Mesoderm Endoderm Neural crestcells (c) Somites Archenteron (a) Neural plate formation Neural tube (b) Neural tube formation

30. Fig. 47-12a Neural plate Neuralfold 1 mm Neural folds Notochord Ectoderm Mesoderm Endoderm Archenteron (a) Neural plate formation

31. Fig. 47-12b-1 Neuralfold Neural plate (b) Neural tube formation

32. Fig. 47-12b-2 (b) Neural tube formation

33. Fig. 47-12b-3 Neural crestcells (b) Neural tube formation

34. Fig. 47-12b-4 Outer layerof ectoderm Neural crestcells Neural tube (b) Neural tube formation

35. Fig. 47-12c Neural crestcells Neural tube Somites Eye Tail bud Notochord Coelom Somite Archenteron(digestivecavity) SEM 1 mm (c) Somites

36. Notochord (vertebrate) Mesenchyme cells Fig. 47-13 Eye Neural tube Notochord Forebrain Somite Heart Coelom Archenteron Endoderm Lateral fold Mesoderm Bloodvessels Ectoderm Somites Yolk stalk Yolk sac These layersform extraembryonicmembranes Neural tube YOLK (a) Early organogenesis (b) Late organogenesis

37. organogenesis Fig. 47-14 ECTODERM MESODERM ENDODERM NotochordSkeletal systemMuscular systemMuscular layer ofstomach and intestineExcretory systemCirculatory and lymphaticsystems Reproductive system(except germ cells) Dermis of skinLining of body cavityAdrenal cortex Epidermis of skin and itsderivatives (including sweatglands, hair follicles)Epithelial lining of mouthand anusCornea and lens of eyeNervous systemSensory receptors inepidermisAdrenal medullaTooth enamelEpithelium of pineal andpituitary glands Epithelial lining ofdigestive tractEpithelial lining ofrespiratory systemLining of urethra, urinarybladder, and reproductivesystemLiverPancreasThymusThyroid and parathyroidglands

38. Extraembryonic membrane Amnion Fig. 47-15 Allantois Embryo Amnioticcavitywithamniotic fluid Albumen Shell Yolk (nutrients) Chorion Yolk sac

39. Mammalian development Endometrialepithelium(uterine lining) Expandingregion oftrophoblast Fig. 47-16-5 Maternalbloodvessel Uterus Inner cell mass Epiblast Trophoblast Hypoblast Blastocoel Trophoblast Expandingregion oftrophoblast Amnion Amnioticcavity Chorion Ectoderm Epiblast Mesoderm Hypoblast Endoderm Yolk sac (fromhypoblast) Yolk sac Extraembryonicmesoderm cells(from epiblast) Extraembryonicmesoderm Chorion (fromtrophoblast) Allantois

40. Ectoderm Morphogenesis: Cell type, position, and adhesion Fig. 47-17-6 Neuralplate Microtubules Actin filaments Neural tube

41. Convergent extension Fig. 47-18 Convergence Extension

42. CAMs(cell adhesion molecules): Cadherin Fig. 47-19 RESULTS 0.25 mm 0.25 mm Control embryo Embryo without EP cadherin EP cadherin is required for proper cell organization in the blastula

43. RESULTS An organized fibronectin matrix is required for convergent extension. Experiment 1 Fig. 47-20 Injection the molecule to block the interaction of fibronectin and its receptor Control Matrix blocked Experiment 2 Tightly packed in a column Control Matrix blocked

44. The developmental fate of cells depends on their history and on inductive signals Fig. 47-21 Fate map Epidermis Centralnervoussystem Epidermis 64-cell embryos Notochord Blastomeresinjected with dye Mesoderm Endoderm Larvae Neural tube stage(transverse section) Blastula (a) Fate map of a frog embryo (b) Cell lineage analysis in a tunicate

45. Zygote 0 First cell division Fig. 47-22 Outer skin,nervous system Muscula-ture, gonads Germ line(futuregametes) Nervoussystem,outer skin, muscula-ture Time after fertilization (hours) Musculature 10 Hatching Intestine Intestine Mouth Anus Eggs Vulva ANTERIOR POSTERIOR 1.2 mm

46. Gray cresent affects the developmental potential of the first two daught cells Fig. 47-23a EXPERIMENT Control egg(dorsal view) Experimental egg(side view) Graycrescent Graycrescent Thread

47. Control egg(dorsal view) Experimental egg(side view) Fig. 47-23b EXPERIMENT Graycrescent Graycrescent Thread RESULTS Normal Belly piece Normal

48. The Organizer of Spemann and Mangold Fig. 47-24 EXPERIMENT RESULTS Dorsal lip ofblastopore Primary embryo Secondary(induced) embryo Pigmented gastrula(donor embryo) Nonpigmented gastrula(recipient embryo) Primary structures:Neural tube Notochord Secondary structures:Notochord (pigmented cells) Neural tube (mostly nonpigmented cells)

49. Fig. 47-24a EXPERIMENT Dorsal lip ofblastopore Pigmented gastrula(donor embryo) Nonpigmented gastrula(recipient embryo)

50. RESULTS Primary embryo Fig. 47-24b Secondary(induced) embryo Primary structures:Neural tube Notochord Secondary structures:Notochord (pigmented cells) Neural tube (mostly nonpigmented cells)