Threshold dependent BMP Signaling:

Slides:

Advertisements

Similar presentations

GROWTH FACTOR SIGNALING, HOX GENES AND THE BODY PLAN

Advertisements

Development of the nervous system - I

Positional information: fields, boundaries, and gradients Development requires a dramatic increase in the amount of information contained within the organism.

Cell Differentiation: Cell interactions in Development

Current Model for how cells become neural 1)Default state is neural 2)Local secretion of BMPs by epidermis inhibits neural fate 3)Local secretion of noggin,

Neuroinduction Diffusible morphogen.

Axis Formation and Gastrulation II

Axis determination and early development in amphibians

BRAIN VERSUS SKIN DEVELOPMENT IN FLIES

HeadTail T1 T2 T3 A1 A2A4 A5 A6 A7 A3 A8 Metamorphosis Quiltwork Assembly of a Fly.

How does a single cell make a brain???

Drosophila dorsal/ventral axis detemination How are different tissue types specified at distinct positions on the embryonic dorsal- ventral axis?

Drosophila dorsal/ventral axis detemination

Allantois / placenta. Figure 2.22 The Amniote Chick Egg, Showing the Membranes Enfolding the 7-Day Embryo Chick Embryo.

Drosophila melanogaster development How do Drosophila embryos develop? How can one use genetics to find genes that regulate embryo development?

HeadTail T1 T2 T3 A1 A2A4 A5 A6 A7 A3 A8 Metamorphosis Quiltwork Assembly of a Fly.

D V High [Dorsal] Low [Dorsal] No Dorsal Graded Dorsal Concentration Created by Mother Hierarchy of Gene Action in D/V Patterning Mesoderm Genes Neuroectoderm.

Expression Profiling Using DNA MicroArrays - Each cell type within an organism expresses a unique combination of genes – this is, in part, what makes cells.

欢迎随时提问、切磋！ How does a simple cell turn into a complicated organism? How do genes coordinate and orchestrate the body planning?

V D Latent Dorsalizing Factors The Point of Fertilization Orients the D/V Axis of the Frog.

Development of the nervous system – 2

Developmental stage-specific biphasic roles of Wnt signaling in cardiomyogenesis and hematopoiesis (Atsuhiko T. Naito et al, 2006, Development)

Hox genes and pattern development of vertebrates Pattern formation: harmonious arrays of different elements, such as the array of fingers on the hand,

February 06 Developmental biology: imaginal discs 5 wingless hedgehog/engrailed * after several hours of interdependence of wingless and hedgehog: situation.

Inhibitory Gli3 Activity Negatively Regulates Wnt/  -Catenin Signaling Ulloa F. et al, Current Biology (2007)

Ectoderm Fate Neural tube development Building the brain You can see a lot by looking! The eye Epidermis development.

Formation and patterning of the nervous system

Neuroinduction Diffusible morphogen. Neural plate (Apposition of Different Germbands) Ant Post Endoderm and Mesoderm Involute with Gastrulation: Induction.

Vertebrate Embryonic Patterning 6 Limb Formation.

Genetics of Axis Specification in Drosophila: Dorsal-Ventral Axis Specification Gilbert - Chapter 9.

Differentiation of the Neural Tube Gilbert - Chapter 12.

Drosophila axis detemination; dorsal/ventral polarity How are the embryonic axes set up? How does the embryonic dorsal-ventral axis get translated into.

Examination 4 questions from 6 2 will be compulsory (ie. A big word meaning YOU HAVE TO DO THEM) 2 hours to complete test (portion approx 30mins per question.

Evolutionary conservation of patterning systems

David M. Umulis, Osamu Shimmi, Michael B. O'Connor, Hans G. Othmer

Appendage development

Bio 3411 Lecture IV. Mechanisms of Neural Development

Creation of a Sog Morphogen Gradient in the Drosophila Embryo

BRAIN VERSUS SKIN DEVELOPMENT IN FLIES

Drosophila melanogaster

Iain Patten, Marysia Placzek Current Biology

Volume 7, Issue 3, Pages (September 2004)

Patterning Lessons from a Dorsalized Embryo

Pioneering Work in Vertebrate Neural Development

Genomic Regulatory Networks and Animal Development

Gene-Regulatory Interactions in Neural Crest Evolution and Development

Sorting Sloppy Sonic Cell

A Hedgehog-Insensitive Form of Patched Provides Evidence for Direct Long-Range Morphogen Activity of Sonic Hedgehog in the Neural Tube James Briscoe,

Volume 86, Issue 4, Pages (August 1996)

1 time * transcription factors expressed in large blocks

Volume 21, Issue 1, Pages (July 1998)

FORMING THE NOSE VERSUS TAIL OF A FLY

Hedgehog and Patched in Neural Development and Disease

1 time * transcription factors expressed in large blocks

Dynamics of Inductive ERK Signaling in the Drosophila Embryo

Drosophila Development: Novel Signal Elicits Visceral Response

Formation of the BMP Activity Gradient in the Drosophila Embryo

Volume 111, Issue 5, Pages (November 2002)

Gastrulation Movements: the Logic and the Nuts and Bolts

Creation of a Sog Morphogen Gradient in the Drosophila Embryo

Evo-Devo: Variations on Ancestral Themes

Volume 14, Issue 4, Pages (April 2008)

Stefano De Renzis, J. Yu, R. Zinzen, Eric Wieschaus Developmental Cell

Petros Ligoxygakis, Siegfried Roth, Jean-Marc Reichhart

1 time * transcription factors expressed in large blocks

Jonas Muhr, Thomas M Jessell, Thomas Edlund Neuron

BRAIN VERSUS SKIN DEVELOPMENT IN FLIES

Conserved patterns of Shh expression from mammals to teleosts.

Volume 86, Issue 3, Pages (August 1996)

Drosophila Gastrulation: Identification of a Missing Link

Presentation transcript:

Threshold dependent BMP Signaling: A Conserved Mechanism for Patterning the Ectoderm Ethan Bier Section of Cell and Developmental Biology, UCSD

Epi Neuro Neuro Dorsal Meso snail dpp “sog” sog

Sog blocks BMP invasion of the neuroectoderm Mesodermal Genes Neuronal Genes Epidermal Genes Neuronal Genes BMP B r k Sog Dorsal = M e s o d r m N n - u a l E c t

X Neural Genes are Repressed By BMP Signaling Mesodermal Genes Neuronal Genes Sog Neuronal Genes Epidermal Genes B r k X Dpp = M e s o d r m N n - u a l E c t

Neural Genes are Repressed By BMP Signaling Neuronal Genes Mesodermal Genes = M e s o d r m N n - u a l E c t

Neural Genes are Repressed By BMP Signaling dpp- wt l’sc tkv

X Dpp Invades the Neuroectoderm of sog- Mutants Epidermal Genes Dpp Mesodermal Genes Neuronal Genes Epidermal Genes Neuronal Genes Dpp X Sog = M e s o d r m N n - u a l E c t

Dpp Invades the Neuroectoderm of sog- Mutants Epidermal Genes Neuronal Genes Dpp Mesodermal Genes = M e s o d r m N n - u a l E c t

Dpp Invades the Neuroectoderm of sog- Mutants wt sog-; Dpdpp

The Default state of Ectoderm is Neural

Subdivision of the neuroectoderm Dorsal Dpp Non-neural genes Neural genes Sog B r k

Subdivision of the neuroectoderm Dorsal Dpp Non-neural genes Neural genes Neuronal genes Msh Ind Vnd

Patterning the neuroectoderm in flies and mice Dorsal Dpp ind msh vnd dpp Drosophila Neuroectoderm Mouse Neural Tube Sonic Hh BMPs Msx Nkx2.2 Gsh

Ventral dominance Ventral dominant repression D msh ind vnd V

Generating lateralized embryos ECT 3 2 NE 2 1 MES Mid-lateralized Embryos -> Uniform “ind” levels of Dorsal st2-dpp “ind”

Gene expression in lateralized embryos Mid-Lateralized Embryos ind msh vnd dpp Dorsal

Localized Dpp activity along the A/P axis sog+ sog dpp pMAD sog dpp pMAD sog-

Subdivision of the neuroectoderm dpp merge

Gene expression borders shift in BMP- cells ECT NE MES 1 3 2 st2-brk Brk Dpp st2-brk

Dosage dependent BMP-repression in vertebrates

BMPs can pattern lateralized vertebrate embryos

Conserved Patterning of the Neuroectoderm? Drosophila Neuroectoderm Nkx2.2 Gsh/Pax6 Msx1/2 BMP4 Chd Ventral Midline = Floorplate Vertebrate Neuroectoderm msh vnd ind Dpp Sog Ventral Midline