Brainscape's Knowledge GenomeTM


Top Flashcards (Certified)
All Flashcards

Genetics > L21-23: Developmental Genetics > Flashcards

L21-23: Developmental Genetics Flashcards

1
Q

What is developmental biology?

A

The study of the process by which organisms grow and develop
Focuses on growth, differentiation and morphogenesis

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
2
Q

Why is developmental biology important?

A

To understand congenital malformations and diseases and understanding regeneration, repair, aging and cancer

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
3
Q

What is development in mammals?

A

The period between fertilisation and birth

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
4
Q

What is the developing organism known as?

A

An embryo

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
5
Q

What does the study of developmental biology focus on?

A

The initiation and construction

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
6
Q

Where does most organogenesis occur?

A

During embryogenesis

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
7
Q

Where do most congenital anomalies take place?

A

In the first 8 weeks

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
8
Q

What are the 3 general approaches to studying development?

A

Anatomical
Physical
Genetic

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
9
Q

What is a model organism?

A

A well established experimental biological system

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
10
Q

Which gene in the eye can be studied to find functionality?

A

The Pax6 gene

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
11
Q

What is the oldest know bilaterian?

A

The Ikaria wariootia

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
12
Q

Which genes are focused on in Drosophila?

A

Homeotic selector genes (Homeobox genes)

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
13
Q

What is temporo-spatial collinearity?

A

When genes are expressed in chronological order

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
14
Q

Why is Drosophila useful?

A

-Genome sequenced
-Genes have some homologues in mammals
-Many mutants available
-Short life cycle
-Easily accessed larvae
-Allowed the understanding of basic gene networks that regulate early body plan

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
15
Q

How can we find what a gene does?

A

By removing it

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
16
Q

Why are zebrafish useful?

A

-Genome sequenced
-Fundamental developmental processes similar to mammals
-Easy to manipulate genetically
-Easily to manipulate experimentally
-Regenerates body parts
-Transparent embryos

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
17
Q

Why are amphibians useful?

A

-Have large embryos to be easily manipulated
-More similar anatomically to mammals than files/fish
-Capable of regenerating body parts

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
18
Q

Why are birds useful?

A

-Large accessible eggs
-Easy to manipulate and image
-Anatomically similar to mammals

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
19
Q

What is a disadvantage of using birds as a model?

A

They have complex genetics

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
20
Q

Why are mice useful?

A

-Genome sequenced
-Similar to human
-Large number of mutants available
-Possible to manipulate genome
-Relatively rapid life cycle
-Model of choice for most developmental genetics

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
21
Q

What are the disadvantages of using mice as a model?

A

-Difficult to physically manipulate
-Relatively affordable

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
22
Q

What genetic tools are available for use?

A

-Morpholinos (siRNA)
-Chemical mutagenesis
-Transgenesis (transient)
-Transgenesis (germline)
-Single gene knockout and knockins
-Conditional gene knockouts
-CRISPR

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
23
Q

Why are animal models essential?

A

-Cannot experiment on humans
-Cannot model disease processes in cell culture
-Cannot test toxicity of new drugs/ disease treatment in cell culture
-Cannot model complex development/ aging processes in cell culture

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
24
Q

What would be advantages to using humans as a model?

A

-Have genetic disease kindreds
-Many tools available for identifying disease genes

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
25
What are disadvantages to using humans as models?
-Cannot genetically manipulate (ethical!!) -Complex genetics -Limited access to human embryos
26
What are organoids?
Self-organising three-dimensional cell cultures
27
Where were organoids derived from?
Pluripotent stem cells
28
What are the main functions for organoids?
They are used to recapitulate early stages of development
29
What are the key characteristics for a good model for developmental genetics research?
-Sequenced genome -Anatomically resembles human -Rapid rate of development to maturity -Large number of offspring -Easily manipulated and genetically tracible -Readily available
30
When does patterning occur?
Early in development
31
What is morphogenesis?
The emergence of form, the process by which an organism/structure beings to develop 3D form
32
What are the 3 fundamental processes in developmental biology?
Morphogenesis Differentiation Growth
33
What is axis formation?
The establishment of body plan
34
What is a body plan?
The map of an organism
35
How many axis are crucial to the foundation of the body?
3
36
What are the 3 crucial axes of the body?
-Antero-posterior -Dorso-ventral Left-right
37
What is body axis dependent on?
Different parts of the embryo becoming distinct
38
What are examples of long range signalling molecules required in embryos?
Hedgehog, Wnt and TGFbeta
39
What is an example of a short range signalling molecule required in embryos?
Notch
40
What determines genes being activated in long range signalling?
The type of signal and how strongly it binds
41
What are the 4 components to cell signalling?
-Release and transmission of a signal by source cell -Reception of the signal by the target cell -Transduction of the signal -Cellular response - requires activation/repression of gene expression
42
What is used to pattern the embryo?
Growth factors (morphogens)
43
How do morphogens work?
Form gradients as they diffuse which activates different genes at different concentrations and determines specific characteristics
44
What is the first step to establish Anterior-posterior polarity in flies?
A gradient of bicoid
45
How do morphogens achieve long range signalling in cellularised tissues?
-Different mechanisms suggested -Diffusion over long distances -Relay from cell to cell -Cellular extensions -Not mutually exclusive (different morphogens, different mechanisms)
46
What is the sonic hedgehog signalling?
It is a crucial vertebrate morphogen
47
What are the signalling centres in early mammalian embryos?
-Anterior visceral endoderm (AVE) - first, patterns anterior part of embryo -Node - patterns whole embryo, works cooperatively with AVE at anterior
48
Where does the breaking of symmetry first take place?
At the node
49
Which organs differ from left to right?
Left - heart, stomach, spleen Right - liver Lungs have different number of nodes
50
What is the L-R signalling pathway?
-Initiated at the node -Morphogens secreted -Nodal signalling activated on left side of embryo -Nodal activates Pitx2 regulating downstream gene expression -organ specific process when enough Pitx2 governing asymmetric organ development
51
What is the function of the Pitx2 gene?
Regulates downstream gene expression
52
What does the L-R signalling pathway suggest?
That the right side is default
53
How does Shh (sonic hedgehog signalling) act in L-R signalling?
it acts at the midline barrier to stop left signals getting to the right
54
What tools were used to teach L-R patterning?
Physical tools: inverting and transplanting the node Genetic tools: Knockout Lefty-1/ Shh gene
55
What are the consequences to the Nodal being on the left side?
The thorax becomes inverted (heart and lungs switch)
56
What are the consequences to the nodal being on the right side?
The organs in the abdomen switch sides or both organs in the abdomen and in the thoracic cavity are switched
57
What are the consequences to nodal being on both sides?
Left isomerism the organs on the left are mirrored in the right side
58
What are the consequences of nodal being on neither side?
Right isomerism the organs on the right are mirrored in the left side
59
Which morphogens pattern the AP axis?
-Wnt signals specify the anterior -RA patterns the midbrain, hindbrain and trunk -FGF gradient patterns the caudal region
60
Which genes pattern the AP axis?
Hox
61
How many Hox genes are there in mammals?
4
62
How are the specific identities of AP patterned structures defined?
By homeobox-containing genes
63
What happens to embryos when Hox6 is activated in ribless regions?
Extra ribs are found
64
What happens when Hox10 is expressed in the regions ribs are located?
No ribs develop in the embryo
65
What happens when the Hox10 gene is inactive?
Ribs become everywhere
66
Which signals are contained in D-V patterning when neural tube is patterned?
BMP dorsal region Shh ventral region
67
Why is D-V patterning essential?
For normal development of the nervous system
68
Where are limbs patterned?
In the proximal-distal axis
69
Which structure is required for limb outgrowth?
Apical ectodermal ridge (AER)
70
What is the result of disrupting Hox genes?
Digit patterning defects
71
How does Thalidomide impact patterning?
It disrupts limb patterning by stopping the production of blood vessels which blocks proliferation and altering the expression of Shh, FGF and Hox genes
72
Which transcription factor is degraded from Thalidomide?
Sall4
73
What is the impact of Sall4 mutations?
Can cause Duane Radial Ray Syndrome
74
What does Sall4 regulate?
Key growth factors and Hox genes in developing limbs
75
What are congenital malformations?
Malformations that are already present at birthW
76
hen do congenital malformations take place?
During embryogenesis
77
Why do congenital anomalies take place?
As a result of disruption of normal development
78
What environmental factors cause congenital malformations?
-Radiation -Maternal diabetes -Fever -Prescription drugs -Recreational drugs -Pollutants -Dietary deficiencies/ excesses
79
What genetic factors cause congenital malformations?
-Chromosomal defects -Syndromes -Single genes -Multi-gene interactions
80
What is the anatomical approach?
The study of naturally occurring mutations in humans and animal models Use histological techniques to study how defective structures are formed and how they end up
81
What are the key methodologies for anatomy?
-Gross morphology -Histology
82
What is the process of histology?
-Embryo/tissues dehydrated -Embedded in paraffin wax -Thin slices cut -Different tissues/cell types visualised
83
What is the physical manipulation approach?
-It is based on the principle that understanding abnormal development tells us about normal development -Manipulation of developing embryos used to ask specific questions and test hypotheses -Common methodologies are physical and chemical
84
What are the key methodologies for the physical manipulation approach?
-Removal of part of the embryo -Replacing one part of an embryo with another -Using a drug to interfere with a developmental process
85
What is the genetic approach?
Studying the genes of the families with congenital malformations
86
What are the key developmental genetic techniques?
-Visualisation of gene/protein expression -Transcriptomic sequencing -Measurement of levels of gene/protein expression -Disruption of gene function (total and conditional knockout) -Ectopic or "extra" gene expression (knockins, transgenes)
87
What is gene expression analysis?
Shows when genes are active Gives spatial and temporal information Links genes to specific cell types, tissues/ organs
88
What are methods for analysing gene expression?
-In situ hybridisation -Immunohistochemistry (uses antibodies) -Linkage of gene regulatory elements to a reporter gene
89
What is the effect of knocking out a gene?
Shows the effect it has on the embryo
90
What is an example of a knockout mouse?
CRISPR-Cas9
91
What is the benefit of the CRISPR-Cas9 mouse?
Generates mutants faster, with higher efficiency and at a lower cost
92
What are the different genetic manipulations that are possible?
Knockout of genes (shows what happens when function is deleted) Single amino acid-substitution (allows reproduction of human mutations) Floxed mice (allow knockout in defined spatio-temporal manner)
93
What is gastrulation?
Where 3 germ layers are formed
94
When does gastrulation take place?
In early development
95
What is involved in gastrulation?
Cell signalling and cell movements
96
What are the 3 different cell types developed during gastrulation?
Zygote, blastocyte and gastrula
97
How can gastrulation be replicated?
During differentiation of stem cells
98
What are the factors of neural tube defects (NTDs)?
-One of the most common congenital malformations -~2/1000 live births -300,000 babies born with NTD each year -Multifactorial -Caused by abnormalities in the normal process of neurulation
99
What is the Lp mouse?
It is a model of severe neural tube defects
100
What happens during NTDs?
Embryos are short and neural tube closure is not initiated, and there is a broadened floor plate
101
How was it tested that the broad floor plate prevents the neural folds coming together?
The neural tube was tied together bringing the folds together which resulted in no neural tube closure
102
What is the Lp gene known as in Drosophila?
Vangl2
103
What is Vangl2 involved in?
It is a component of a signalling pathway (Wnt dependent pathway) In flies, the pathway regulates position of cells in cuticle and in eye Regulates the convergence-extension movements and gastrulation in vertebrates
104
What is PCP signalling?
It takes place at gastrulation By a process of cell intercalation Results in the narrowing and lengthening of the embryo
105
What is the result of defects in CE?
Prevents neural tube closure
106
What are therapies of NTDs?
-Folic acid (not NTDs seen in Lps) -B vitamin - inositol
107

Genetics (11 decks)

Brainscape helps you reach your goals faster, through stronger study habits.
© 2025 Bold Learning Solutions. Terms and Conditions