Genetic Effects of Stress in Vervet Monkey

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Genetic Effects of Stress in Vervet Monkey

• Olivera Grujic
• Dr. Eleazar Eskins Lab, UCLA
• Dr. Nelson Freimers Lab,UCLA
• SoCalBSI, 2008

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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!
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Challenging of Studying Genetic Factors of Stress

• Complex trait
• Experiments in humans
• Need
• Model organism that reacts to stress!

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Vervet Research Colony
African Vervets (Chlorocebus aethiops sabaeus)

• Inbred pedigree
• 1000 members
• Small number brought to the Carribean (300-400
  years ago)
• 57 wild-caught brought from St. Kitts to UCLA
  (1975-1989)
• Colony moved from UCLA to Wake Forest (in January
  2008)

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Advantages of Researching Vervet over Human
Population

• 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 2104(40)15811-6. Epub 2007 Sep
20. Jasinska AJ, et al. A genetic linkage map of
vervet monkey. (2007) Mamm Genome 18347360.
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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)!

• Before move
• Blood samples from 380 individuals
• Brain tissue from 12 individuals
• 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

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Challenges

1. No vervet genome and no vervet microarrays
2. Not much known about gene expression in primate
   brain
3. Mostly collecting blood data
4. Available expression data only before move

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First Task

• Assess quality of DNA probes
• Identify inter-species sequence differences

Vervet BAC end sequences submitted to NCBI in
batches
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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
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ResultsProbe Comparison
Length
Freq
50 197 49 225 48 186 47 160 46 146 45 121 44 104 4
3 70 42 81 41 55 40 57 39 45 38 44 37 43 36 43 35
64 34 44 33 41 32 45 31 47 30 35 29 39 28 51 27 61
26 67 25 104 24 94 23 208 22 322 21 638 20 1198 1
9 1662 18 3382 17 6286 16 5100 15 1046 14 0
15 nucleotides 5
16 nucleotides 23
20 nucleotides 5
19 nucleotides 8
18 nucleotides 15
17 nucleotides 28
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Probe Alignments
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Second Task

• 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

• Head of Caudate
• Cereballar Vermis
• Hippocampus
• Frontal Pole

• 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!
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Blood
Head of Caudate
Cerrebalar Vermus
Hippocampus
Frontal Pole
DLPFC
Orbital Frontal
Pulvinar
Occipital pole
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Results Clustering
Individuals
Tissue Type
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Blood Tissue
Samples
Genes
Cluster1
Cluster2
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GO Analysis on Cluster 1
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GO Analysis on Cluster 2
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Future Work

• Third Task brain to blood mapping
• Fourth Task compare pre-move and post-move
  expression data

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Acknowledgments

• UCLA
• Dr. Eleazar Eskin
• Dr. Nelson Freimer
• Dr. Ania Jasinska
• My Labmates

• Funded by

• 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