Ability to molt Takes about 2 days to reach reproductive maturity Takes 4 days to reach reproductive maturity Start of visible segmentation at ~2.5 days Time of hatching or birth similar to xenopus
a. C. elegans b. zebrafish
6. Model organism (among the six) with the fastest a. rate of development to reach adult stage b. 7. Model organism (among the 6) with the slowest rate of development to reach adult stage 8. Can yield high numbers of embryos for genetic manipulation 9. Fertilization is external 10. Microsurgery from eggs is possible 11. Shorter time period (bet 2 model org.) to start the formation of germ layers 12. Takes about 3.5 months to reach sexual maturity 13. Takes about 5 months to reach sexual maturity 14. Takes about 9 months to reach sexual maturity 15. Capable of molting/metamorphosis
drossophila xenopus
a. Chick b. Mouse
16. Beginning of Balbiani body assembly 17. Reduction of pigmentation at the animal hemisphere 18. Accumulation of pigment granules at the vegetal 19. Convergent extension 20. Beginning of axis specification
a. Oogenesis b. Cleavage
21. Convergent extension takes place 22. Involves the non-canonical wnt signaling pathway 23. High gene expression of sox2 and N-CAM 24. Dependent on the formation of the Spemann organizer 25. Requires high concentration of BMP4
a. Gastrulation b. Neurulation
26. Region expressing high concentration of BMP inhibitors 27. Regional specification formed immediately after cortical rotation 28. Formation is favoured at low vegT expression 29. Formation is favoured at high vegT expression 30. Expresses high concentration of xnrs
a. Nieuwkoop centre b. Spemann’s organzer
31. High expression of BMP4 32. High expression of follistatin 33. Default fate of the dorsal-ventral region near the Spemann organizer 34. Fate of ectodermal cells 35. Fate of yolky endoderm
pole
a. Epidermis formation b. Brain formation
36. Regulates convergent extension during gastrulation 37. Wnt5a as the dominant ligand 38. Leads to the stabilization of beta-catenin 39. Involves the phosphoprotein dishevelled 40. Leads to the activation of RhoA and Rac 41. Requires the frizzled receptor
a. Wnt “canonical” pathway b. Wnt planar polarity pathway
Sequencing: Oogonium maturation into primary oocyte 42. Expression and association of VegT and Veg1 within the Balbiani body 43. Cdc25 phosphorylation 44. Activation of MPF 45. Release of progesterone from ovarian follicle cells 46. c-Mos activation Fertilization 47. secondary oocytes arrested in metaphase II 48. release of second polar body 49. rise in intracellular Ca+ 50. secondary oocyte fertilized by sperm 51. destruction of c-mos nd Cdk2 complex Cleavage 52. transcription of zygotic genome commence 53. cytoplasmic rearrangement 54. accumulation of beta catenin in the region of blastoporal lip 55. secretion of dorsalizing factors 56. formation Spemann organizer 57. a. b. c. d. e.
dorsalizing factor ventralizing factor c. dorsal mesoderm ventral mesoderm ectoderm
a. Endoderm b. Neural plate formation region of the brain c. Primordial germ cells d. Highly expressed in gut tissues 67. 68. 69. 70. 71. 72. 73. 74. 75. 76.
