1. Development system 5-2-2016

3. Type of questions developmental biology seeks to answer • How do cells arising from a fertilized egg become different from one another?(differentiation) • How do cells become organized into complex structures such as limbs? (patterning and morphogenesis) • What controls the behavior of individual cells such that these highly organized patterns emerge? • How are the organizing principles of development embedded within the egg, and within the DNA? • How have changes in developmental program and in gene expression, led to the evolution of the great diversity of animal forms? (EVO-DEVO)

8. Gene regulatory networks for development PNAS 102: 4936–4942; 2005

15. Are all embryos looks similar?

19. Historical origin of developmental biology

24. A Hierarchy of Inductive Interactions Subdivides the Vertebrate Embryo

26. Hox Genes Permanently Pattern the A-P Axis What is the regulatory role of Ubx in development?

30. The Developmental Potential of Cells Becomes Progressively Restricted

31. Regulatory DNA Seems Largely Responsible for the Differences Between Animal Species

32. Through Combinatorial Control and Cell Memory, Simple Signals Can Generate Complex Patterns

33. Two different types of development program British vs American

34. Small Numbers of Conserved Cell–Cell Signaling Pathways Coordinate Spatial Patterning

35. Morphogens Are Long-Range Inductive Signals That Exert Graded Effects

36. Morphogens Are Long-Range Inductive Signals That Exert Graded Effects Production (pulse or steady state), diffusion (fast or slow) and degradation (half life( determine the range and steepness of its resulting gradient

37. Lateral Inhibition Can Generate Patterns of Different Cell Types

38. Short-Range Activation and Long-Range Inhibition Can Generate Complex Cellular Patterns

39. Asymmetric Cell Division Can Also Generate Diversity

40. Initial Patterns Are Established in Small Fields of Cells and Refined by Sequential Induction as the Embryo Grows

41. Different Animals Use Different Mechanisms to Establish Their Primary Axes of Polarization

42. Studies in Drosophila Have Revealed the Genetic Control Mechanisms Underlying Development

43. Egg-Polarity Genes Encode Macromolecules Deposited in the Egg to Organize the Axes of the Early Drosophila Embryo

44. Egg-Polarity Genes Encode Macromolecules Deposited in the Egg to Organize the Axes of the Early Drosophila Embryo

45. Three Groups of Genes Control Drosophila Segmentation Along the A-P Axis

46. Three Groups of Genes Control Drosophila Segmentation Along the A-P Axis

47. A Hierarchy of Gene Regulatory Interactions Subdivides the Drosophila Embryo

48. A Hierarchy of Gene Regulatory Interactions Subdivides the Drosophila Embryo

49. Egg-Polarity, Gap, and Pair-Rule Genes Create a Transient Pattern That Is Remembered by Segment-Polarity and Hox Genes

50. A Competition Between Secreted Signaling Proteins Patterns the Vertebrate Embryo