Figure 20.1 Sperm and Egg Differ Greatly in Size Figures\Chapter20\High-Res\life7e-fig-20-01-0.jpg

Figure 20.4 Patterns of Cleavage in Four Model Organisms (Part 1) Figures\Chapter20\High-Res\life7e-fig-20-04-1.jpg

Figure 20.4 Patterns of Cleavage in Four Model Organisms (Part 2) Figures\Chapter20\High-Res\life7e-fig-20-04-2.jpg

Figure 20.5 The Mammalian Zygote Becomes a Blastocyst (Part 2) Figures\Chapter20\High-Res\life7e-fig-20-05-2.jpg

Figure 20.7 Twinning in Humans Figures\Chapter20\High-Res\life7e-fig-20-07-0.jpg

Two Blastulas

The Primary Germ Layers zygote blastula gastrula chordates vertebrates brain, spinal cord, spinal nerves ventral nerve cord lining of respiratory tract pharynx epidermis lining of digestive tract endoderm ectoderm neural crest gastrula notochord gill arches, sensory ganglia, Schwann cells, adrenal medulla glands circulatory system mesoderm integuments pancreas, liver blood, vessels outer covering of internal organs gonads somites heart lining of thoracic and abdominal cavities kidney segmented muscles skeleton dermis

Figure 20.8 Gastrulation in Sea Urchins Figures\Chapter20\High-Res\life7e-fig-20-08-0.jpg

Figure 20.9 Gastrulation in the Frog Embryo (Part 1) Figures\Chapter20\High-Res\life7e-fig-20-09-1.jpg

Figure 20.9 Gastrulation in the Frog Embryo (Part 2) Figures\Chapter20\High-Res\life7e-fig-20-09-2.jpg

Figure 20.9 Gastrulation in the Frog Embryo (Part 3) Figures\Chapter20\High-Res\life7e-fig-20-09-3.jpg

Neurulation “For the real amazement, if you wish to be amazed, is this process. You start out as a single cell derived from the coupling of a sperm and an egg; this divides in two, then four, then eight, and so on, and at a certain stage there emerges a single cell which has as all its progeny the human brain. The mere existence of such a cell should be one of the great astonishments of the earth. People ought to be walking around all day, all through their waking hours calling to each other in endless wonderment, talking of nothing except that cell.” --Lewis Thomas

Figure 20.15 Neurulation in the Frog Embryo (Part 1) Figures\Chapter20\High-Res\life7e-fig-20-15-1.jpg

Figure 20.15 Neurulation in the Frog Embryo (Part 2) Figures\Chapter20\High-Res\life7e-fig-20-15-2.jpg

Figure 20.16 The Development of Body Segmentation Figures\Chapter20\High-Res\life7e-fig-20-16-0.jpg

Figure 20.10 Spemann’s Experiment Figures\Chapter20\High-Res\life7e-fig-20-10-0.jpg

Figure 20.11 The Dorsal Lip Induces Embryonic Organization Figures\Chapter20\High-Res\life7e-fig-20-11-0.jpg

Figure 20.2 The Gray Crescent Figures\Chapter20\High-Res\life7e-fig-20-02-0.jpg

Figure 20.3 Cytoplasmic Factors Set Up Signaling Cascades Figures\Chapter20\High-Res\life7e-fig-20-03-0.jpg

Figure 20.12 Molecular Mechanisms of the Primary Embryonic Organizer Figures\Chapter20\High-Res\life7e-fig-20-12-0.jpg

multiple signals pattern the vertebrate neural tube and somite NC Shh sclerotome dermomyotome motorneurons fp dorsal epidermal ectoderm NT Wnt? somite Wnt BMP-4 FGF5? lateral mesoderm NT-3 multiple signals pattern the vertebrate neural tube and somite 6

Figure 19.9 Embryonic Inducers in the Vertebrate Eye Figures\Chapter19\High-Res\life7e-fig-19-09-0.jpg

Induction in eye development

Figure 19. 10 Induction during Vulval Development in C Figure 19.10 Induction during Vulval Development in C. elegans (Part 1) Figures\Chapter19\High-Res\life7e-fig-19-10-1.jpg

Figure 19. 10 Induction during Vulval Development in C Figure 19.10 Induction during Vulval Development in C. elegans (Part 2) Figures\Chapter19\High-Res\life7e-fig-19-10-2.jpg

Origami: sets of instructions (programs) to build 3-D models of organisms out of paper – Is this how developmental programs work?

Determination Differentiation A B C D E F G H The “landscape” of developmental programs: The determination of different cell types involves progressive restrictions in their developmental potentials. When a cell “chooses” a particular fate, it is said to be determined. Differentiation follows determination, as the cell elaborates a cell-specific developmental program. Determination Differentiation Differentiated Cell Types A B C D E F G H

2-D Electrophoresis of proteins extracted from two different mouse tissues Mouse Liver Proteins Mouse Lung Proteins

Sets of gene products in two cell types A A & B B Cell types A & B share a common set of “housekeeping” gene products and a set of unique “luxury” gene products that represent the A or B developmental program

Figure 19.2 Developmental Potential in Early Frog Embryos Figures\Chapter19\High-Res\life7e-fig-19-02-0.jpg

Figure 19.3 Cloning a Plant (Part 1) Figures\Chapter19\High-Res\life7e-fig-19-03-1.jpg

Figure 19.3 Cloning a Plant (Part 2) Figures\Chapter19\High-Res\life7e-fig-19-03-2.jpg

Figure 19.4 A Clone and Her Offspring (Part 1) Figures\Chapter19\High-Res\life7e-fig-19-04-1.jpg

Figure 19.4 A Clone and Her Offspring (Part 2) Figures\Chapter19\High-Res\life7e-fig-19-04-2.jpg

Figure 19.4 A Clone and Her Offspring (Part 3) Figures\Chapter19\High-Res\life7e-fig-19-04-3.jpg

Figure 19.5 Cloned Mice Figures\Chapter19\High-Res\life7e-fig-19-05-0.jpg

21_41_cloning.jpg 21_41_cloning.jpg

What is a stem cell? stem cell determined cell differentiated cell

21_39_hemopoietic.jpg 21_39_hemopoietic.jpg

Recent breakthroughs in stem cell research : stem cells can be obtained from adults and embryos/fetal tissue stem cells are multipotent! this very likely has theraputic value

Determination Differentiation A B C D E F G H The “landscape” of developmental programs: The determination of different cell types involves progressive restrictions in cellular developmental potentials. When a cell “chooses” a particular fate, it is said to be determined. Differentiation follows determination, as the cell elaborates a cell-specific developmental program. Determination Differentiation Differentiated Cell Types A B C D E F G H

Uses of human embryos obtain stem cells somatic cell transfer, then obtain stem cells use stem cells that are coaxed to develop into different tissues for therapeutic purposes

Figure 20.14 A Human Blastocyst at Implantation Figures\Chapter20\High-Res\life7e-fig-20-14-0.jpg

Week 1 Week 2

Week 3 Week 4 Week 5

Figure 19.6 The Potential Use of Embryonic Stem Cells in Medicine (Part 1) Figures\Chapter19\High-Res\life7e-fig-19-06-1.jpg

Figure 19.6 The Potential Use of Embryonic Stem Cells in Medicine (Part 2) Figures\Chapter19\High-Res\life7e-fig-19-06-2.jpg

Figure 19.7 Asymmetry in the Early Embryo (Part 1) Figures\Chapter19\High-Res\life7e-fig-19-07-1.jpg

Figure 19.7 Asymmetry in the Early Embryo (Part 2) Figures\Chapter19\High-Res\life7e-fig-19-07-2.jpg

Figure 19.8 The Principle of Cytoplasmic Segregation Figures\Chapter19\High-Res\life7e-fig-19-08-0.jpg

Figure 19.9 Embryonic Inducers in the Vertebrate Eye Figures\Chapter19\High-Res\life7e-fig-19-09-0.jpg

Figure 19.11 Apoptosis Removes the Tissue between Fingers Figures\Chapter19\High-Res\life7e-fig-19-11-0.jpg

Figure 19.12 Organ Identity Genes in Arabidopsis Flowers (Part 1) Figures\Chapter19\High-Res\life7e-fig-19-12-1.jpg

Figure 19.12 Organ Identity Genes in Arabidopsis Flowers (Part 2) Figures\Chapter19\High-Res\life7e-fig-19-12-2.jpg

Figure 19.13 A Nonflowering Mutant Figures\Chapter19\High-Res\life7e-fig-19-13-0.jpg

c. b. a. d. e. Nurse cells Anterior Posterior Movement of maternal mRNA Oocyte Follicle Fertilized egg a. d. e. Three larval stages Syncytial blastoderm Cellular blastoderm Nuclei line up along surface, and membranes grow between them to form a cellular blastoderm. Segmented embryo prior to hatching Metamorphosis Abdomen Thorax Head Hatching larva Copyright © The McGraw-Hill Companies, Inc. Permission required for reproduction or display. Nucleus Embryo

Egg with maternally-deposited mRNA A P bicoid nanos Gradients of informational proteins encoded by maternal mRNA Gap Genes hunchback Krupple Knirps Pair RuleGenes Segment Polarity Genes Homeotic Genes

Figure 19.15 A Gene Cascade Controls Pattern Formation in the Drosophila Embryo Figures\Chapter19\High-Res\life7e-fig-19-15-0.jpg

Fig. 19.13

Figure 19.14 Bicoid and Nanos Protein Gradients Provide Positional Information (Part 1) Figures\Chapter19\High-Res\life7e-fig-19-14-1.jpg

Figure 19.14 Bicoid and Nanos Protein Gradients Provide Positional Information (Part 2) Figures\Chapter19\High-Res\life7e-fig-19-14-2.jpg

hunchback & Krupple - gap class

even skipped - pair rule class

fushi tarazu (ftz) & even skipped (eve) - pair rule class

engrailed - segment polarity class

Fig. 19.17

wild-type Antennapediamutant Fly heads

Fig. 19.18

wildtype mouse Hoxb-4 knockout 5

2