Transcript 4061-intro-lecture1-update-jan-4-2017

4061 Molecular and Cellular Principles of
Animal Development
4061 Molecular and Cellular Principles of
Animal Development
• Classic approaches to embryonic development
• Molecular approach- genes take centre stage ‘genetic
programs underlying development’
• ‘Programs executed by molecular networks of proteins
operating within and between cells’
• ‘In order to understand development we need to
understand the underlying genetic circuitry’
• ‘Moving from an organism-based approach towards
molecular mechanisms’
Primary Question
• How can a complex animal emerge from a single egg?
Fourth century BC Aristotle dissected chicken’s eggs
Principle of ‘epigenesis’- development
a process of growth in size combined with increasing
complexity and organization
Descriptive Embryology
• Development of microscope in seventeenth century
Experimental Embryology
• Wilhelm Roux- ‘empirical approach
Manipulate frog embryo and observe consequences
‘embryonic induction’
• Developmental Genetics (70’s)
Drosophila melanogaster – transmission of genetic traits
• Genetics meets Molecular Biology
Clone the developmental genes
• Developmental Biology
Fusion of Molecular Biology, genetics and morphology
• Impact on Society
In vitro fertilization (IVF)
‘Teratology’ effect of environmental agents (chemicals,
viruses, radiation) on embryos
Chromosomal basis of some human birth defects
(amniocentesis)
• Future
Functional genomics - therapeutic targets
- combinatorial chemistry
Tissue repair - Stem cells
- ex vivo tissue engineering
- organogenesis
Genetic engineering - ‘cloning’!!!
Readings from Gilbert 11th edition
• Chapter p1-27 Mechanisms of
Developmental Organization(p1-27 ( 10th
p5-29) Comprehending Development
- intro read for general interest
• Chapter 3 Differential Gene Expression
p45-93 (Ch 2 p31-65 10th)
The essence of embryonic development:
• A regulated expansion in cell numbers, coordinated in space and time with an
increase in cell diversity
Primary Question
How can a complex animal emerge from a single
egg?
Questions of Differentiation
Questions of morphogenesis
Questions of growth
Questions of regeneration
Questions of evolution
Questions of environmental adaptation
SC/BIOL 4061,SC/BCHM 4061 Molecular and
Cellular Principles of Animal Development Winter
term, 2017 OUTLINE
Course Director: John McDermott PhD
Office : 427b Life Sciences Building
Office tel extension: 30344
Email address: [email protected]
Web site:
www.yorku.ca/jmcderm/
Scheduled Office hours: TBA (email for an appointment or to
request an alternate time to meet)
Topic outline
1)
Introduction to Molecular Analysis of Development Descriptive embryology -Genetics and molecular biology
2)
Programs and Regulatory Elements in DNA
3)
Transcriptional Circuits- epigenetic regulation of
gene expression- differential gene expression
4)
Gastrulation and early development- axis
specification and formation
5)
Features of Major Model Organisms- Mouse,
Chick, Drosophila
6)
Techniques for the study of Mouse Development:
gene targeting/editing technology
7)
Receptors, Ligands
8)
Cell-cell communication, Signaling Networks,
Induction and Competence
9)
Molecular Co-ordination of Cell Division and
Differentiation ( Myogenesis)
10)
Focus on Paraxial Mesoderm, Somitogenesis and
Patterning
11)
Cell Death in Development
12)
Lineage Generation - Embryonic and Adult Stem cell
properties and lineage commitment
13)
Cell Type Specification, Induction of pluripotency in
stem cells (iPS) and cell fate programming
14)
Patterning in 1 and 2 Dimensions
15)
Molecular and cellular basis of 3D Patterning- Heart
development
16)
Postembryonic development: Regeneration and
Aging
17)
Developmental mechanisms of evolutionary
conservation and change
Evaluation
1 Test (prior to Reading week -date: Thurs 16th Feb) 30%
1 Essay (HARD COPY due date Tue 28th March by
5pm ) 30%
(In some cases students may be able to do a class
presentation
in lieu of the essay assignment on permission of the
instructor)
1 Test (Final in exam period date -TBA) 40%
Course Text: (11th edition available in York bookstore)
Developmental Biology
Companion web site: www.devbio.com
Scott F.Gilbert
Sinauer Associates, Inc
ISBN 0-87893-384-6
ZYGOTE
CLEAVAGE
GASTRULATION
ectoderm
endoderm
mesoderm
4061
Comparative embryology
snake
tortoise
Ernst Haeckel (4 edn 1903)
chicken
dolphin
monkey
The development of animal model systems.
Nematode
C.elegans
The development of animal model systems
V
Fruit fly
Drosophila A
melanogaster
P
D
The development of animal model systems, cont’d
Frog
Xenopus
laevis
The development of animal model systems, cont’d
Zebrafish
The development of animal model systems, cont’d
Chick
The development of animal model systems, cont’d
Mouse
Types of evidence
• Correlative- weakest
• Loss of function
• Gain of function
A few classical terms concerning cell migration during gastrulation
Programs and regulatory elements
in DNA and RNA
Gilbert, Chapter 3 p45-93 Differential Gene
Transcription
DNA content and number of genes
21,733
17,000
24,189
21,000
DNA content and number of genes, cont’d
Phylogenetic analysis
Fundamental principles of development at the cellular level:
a) Cell proliferation
b) Continuous but regulated increase in cell diversity
General pattern of regulatory sequences
Model for assembly of
the RNA polymerase II
initiation complex on a
TATA-containing
promoter
GENE
mRNA
5`
3`
TF
Gene A (on)
Gene B (on)
mRNA
mRNA
Protein A
Protein B
Gene C (off)
Gene D (on)
mRNA
Protein D
Regulation of Transcription Factors
Homeodomain
Engrailed
Ribbon
Zinc Finger
ZIF 268
Zinc Finger
Gluc. Receptor
Leucine
Zipper GCN 4
GCN 4:DNA
HLH-leucine
zipper MAX
Modular design of eukaryotic transcription factors
Transcription factor x
DNA b.d.
Act.d
C
N
CANNTG
DNA b.d.
unrelated protein
C
N
DNA b.d.
unrelated protein
Act.d
C
N
tgacgtca
Control of CREB activity by cAMP
R
Nucleus
cAMP
R
+
P
Ser 133
R
CREB
CREB
OFF
ON
PKA holoenzyme
PKA catalytic subunit
Regulation of NFkB activity
p50
I
p65
P
p50
I
p65
P
Nucleus
Fig 2.8 Fusion of reporter genes to the enhancer
region
13.5d Myf 5 LacZ reporter expressed in eye,
facial limb muscles and segmented myotome
GFP fused to a lens crystallin promoter in
Xenopus tropicalis
Epigenetic control of gene expression
Nucleosome and chromatin structure
5.10 TAFII250, a TAF that binds TBP, can function as a histone
acetyltransferase
What regulates the transcription factors ?
Cell Signalling
modification
Protein
functional protein
interacting with other proteins
RNA
DNA
Overview of
RNA
processing in
eukaryotes
using β-globin
genes
Alternative Splicing
E1
I1
E2
E1
I2
E2
E1
E2
E3
E1
E3
gene
E3
RNA1
mRNA1
E3
E1
E3
mRNA2
RNA2
Alternative Splicing
E1
I1
E2
E1
I2
E2
E1
E2
E3
E1
E3
gene
E3
RNA1
mRNA1
E3
E1
E3
mRNA2
RNA2