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Genetic Effects of Stress
in Vervet Monkey
Olivera Grujic
Dr. Eleazar Eskin’s Lab, UCLA
Dr. Nelson Freimer’s Lab,UCLA
SoCalBSI, 2008
Project Importance

Evaluate biomedical bases of inter-individual
differences in response to stressor.
Stress Related Diseases:
•Depression
•Post Traumatic Stress Disorder
Response to stress has genetic component!
Challenging of Studying Genetic
Factors of Stress
Complex trait
 Experiments in humans
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Need:
Model organism that reacts to stress!
Vervet Research Colony
African Vervets
(Chlorocebus aethiops sabaeus)
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Inbred pedigree
1000 members
Small number brought to the Carribean (300400 years ago)
57 wild-caught brought from St. Kitts to UCLA
(1975-1989)
Colony moved from UCLA to Wake Forest (in
January 2008)
Advantages of Researching
Vervet over Human Population
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Same stressor
Controlled environment
Good quality of tissue
Simultaneous effect in multiple organ systems
Highly informative pedigree
Vervet genetic map suitable for QTL mapping
Freimer NB, et al. A quantitative trait locus for variation in dopamine metabolism mapped in a primate
model using reference sequences from related species. Proc Natl Acad Sci U S A. 2007 Oct
2;104(40):15811-6. Epub 2007 Sep 20.
Jasinska AJ, et al. A genetic linkage map of vervet monkey. (2007) Mamm Genome 18:347–360.
Data Collection
Moving can be stressful.
Vervet Colony exposed to a major
stressor - all of them were moved under
the same conditions, at the same time
(in controlled way)!
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Before move:
– Blood samples from ~380 individuals
– Brain tissue from 12 individuals
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After move:
– Blood samples from ~340 individuals
– Brain tissue from 4 individuals
Goal: Use samples to determine effects of stress
in terms of:
•gene expression profiles
•interindividual differences
Challenges
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No vervet genome and no vervet microarrays
Not much known about gene expression in
primate brain
Mostly collecting blood data
Available expression data only before move
First Task
Assess quality of DNA probes
Identify inter-species sequence
differences
* Vervet
BAC end sequences
submitted to NCBI in batches
Probe Comparison Workflow
Illumina BeadStudio Output File
341,172 Vervet Sequences
Extract and Add Headings
Convert to
22184 Probe Sequences
Vervet Database
Compare Using BLAST
BLAST Output File
Parse
Top Hit for Each Probe
Count Frequency
Probes per Nucleotides Matched
Length
Results
Probe Comparison
15 nucleotides
5%
16 nucleotides
20 nucleotides
23%
5%
19 nucleotides
8%
18 nucleotides
15%
17 nucleotides
28%
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197
225
186
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104
70
81
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638
1198
1662
3382
6286
5100
1046
0
Freq
Probe Alignments
Second Task
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Characterize regional gene expression in vervet brain
Characterize group of genes with low gene expression
variability between brain and blood
Approach:
Cluster expression data from blood and following brain tissues:
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Head of Caudate
Cereballar Vermis
Hippocampus
Frontal Pole
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Dorsolateral Prefrontal Cortex
Orbital Frontal Cortex
Pulvinar
Occipital Pole
Obtain a list of genes where more than 75% of
variability is due to inter-individual differences!
Blood
Head of Caudate
Cerrebalar Vermus
Hippocampus
Frontal Pole
DLPFC
Orbital Frontal
Pulvinar
Occipital pole
Results: Clustering
Individuals
Tissue Type
Blood Tissue
Genes
Cluster1
Cluster2
Samples
GO Analysis on Cluster 1
GO Analysis on Cluster 2
Future Work
Third Task: brain to blood mapping
 Fourth Task: compare pre-move and
post-move expression data
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Acknowledgments
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UCLA
Dr. Eleazar Eskin
Dr. Nelson Freimer
Dr. Ania Jasinska
My Labmates
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SoCalBSI
Dr. Jamil Momand
Dr. Sandra Sharp
Dr. Nancy Warter-Perez
Dr. Wendie Johnston
Dr. Beverly Krilowicz
Dr. Silvia Heubach
Dr. Jennifer Faust
Ronnie Cheng
SoCalBSI 2008 Interns
Funded by: