Upload
brandon-robertson
View
215
Download
3
Tags:
Embed Size (px)
Citation preview
An Atlas of Gene Expression in
Mouse Development
www.mouseatlas.orgwww.mouseatlas.org
•technology development
•technology implementation
•public access
Pipeline
– Known coding elements– New genes (housekeeping and regulated)– New transcripts– New exons– New regulatory RNAs
Tissues
RNAs
Tags
Transcribed Features
•Tag-to-gene mapping
•longSAGE•longSAGE Lite
•Manual dissection•Laser capture microdissection•RNA purification
Bioinformatics
Major technical accomplishments
• Established a SAGE library construction pipeline aimed at constructing 150 libraries by March 31, 2005.
• Established methods for tissue acquisition and dissection (manual and LCM) that yield high-quality mRNA for SAGE.
• Established methods for construction of
SAGE libraries from nanograms of total RNA.
• Established bioinformatics pipeline for extraction and analysis of 21mer SAGE tags.
SAGE library production queue
88 samples in queue(57% complete)
61 libraries constructed
52 libraries passed QC
39 libraries complete(26 % complete)
179,000 sequence reads5.7 million tags33 tags/read
The majority of tags can be mapped to existing sequence
datasets
Tag Frequency
0
0.1
0.2
0.3
0.4
0.5
0.6
0.7
0.8
0.9
1
1 2 3 4 5 6-10 11-50 51-100 101-1000 >1000
Pro
port
ion o
f ta
gs
Most transcripts are “hit” by a
SAGE tag
4,552,635 tags; 543,545 transcripts
Tags mapped: XXXX
mgcmouse: 22419/24607 0.911
refmouse: 13871/18212 0.762
refmouseX: 17464/25362 0.689
refmouseGS: 19795/42393 0.467
Detection of 3’ endvariants
Mouse Atlas SAGE meta-library:4,552,635 tags, 543,545 tag types
61% of moderately abundant transcripts show multiple tag positions
18,775 transcripts(8,400 genes) >10
52% of highly abundant transcripts show multiple tag position
6,888 transcripts(3,550 genes) >=100
Comparison of all tags to 27,026 transcripts from refseq, refseqX, refseqGS, and mgc:
•Approximately 1.6 variants per locus•1 variant / locus for 58% of genes
•2.8 variants / locus for 42% of genes
Tag-to-genome mapping
Location All tags > 7 tags• Exons 25% 73%• Introns 18% 1.4%• 5kb from a UTR 11.5% 11.5%• Intergenic 15% 4.4%• Minus strand 29.4% 8.9%
The distribution of tags or their annotation varies with the level of expression
62 % of tag “types” map uniquely to the genome
Website Usage
Website Usage
Relationship Between Mouse Efforts
SAGE MouseAltas Project
(Marra and Hoodless)150 SAGE Libraries
MPSS MouseProject
(Chris Austin)94 MPSS Libraries
CGAPSAGEgenie(Greg Riggins)
PublicAccessibility
244 Digital Libraries
5 RNAs to bedirectly compared
Transfer of data(34 libraries to date)
Other efforts to note: Australia, Czech website
Total co-funding
Supplemental Slides
Most transcripts are “hit” by a
SAGE tag 4,552,635 total tags; 543,545 transcripts
Total tags mapped to any transcript = XXXX
mgcmouse anywhere: 22419/24607 = 0.91108
mgcmouse position 1: 20981/24607 = 0.85264
refmouse anywhere: 13871/18212 = 0.76164
refmouse position 1: 12176/18212 = 0.66857
refmouseX anywhere: 17464/25362 = 0.68859
refmouseX position 1: 14664/25362 = 0.57819
refmouseGS anywhere: 19795/42393 = 0.4669
refmouseGS position 1: 15947/42393 = 0.37617
Alternate 3’ ends: Multiple tags map to
a gene
AAAAAAA7 6 5 4 3 2 1
Positions in the transcript are defined by NlaIII sites.
Alternate 3’ end formation (alternate splicing) canresult in different tags identifying the same transcript.
AAAAAAA
AAAAAAA
7 6 5 4 3 2
7 6 5 4
Contaminants/ artifacts
• hnRNA (unspliced mRNA) and genomic DNA not likely to be a major contaminant. 18 % of all tags map to introns versus 1.4% of abundant tags (slide 8).
• Partial digestion not likely to be a major artifact. The majority (58%) of transcripts show only a single variant. Of N manually inspected examples that show multiple variants, m looked like the picture in the next slide
Tag position in the transcript
Splice variants
236 tags detected for transcript nm144802
AAAAAAA7 6 5 4 3 2 1
Rate of tag generation and tag quality
0
100000
200000
300000
400000
500000
600000
700000
800000
900000
1000000
All
95%
99%
Required from May 04 – Mar 05: 1.176 million tags / mo(~36,000 reads)
ProcessProcedural Step QC/QA
Tissues are dissected (LCM, manual)
RNA is extracted
SAGE libraries are built
Libraries are sequenced to >100,000 tags
Tags are mapped to genesDiscoverySpace @ BCGSCSageGenie @ CGAP
Tissue and library information is published
www.mouseatlas.org cgap.nci.nih.gov
Sage tag variation:• Approximately 1.6 variants per locus
•1 variant per locus for 40% of genes• 3.8 variants per locus for 60% of genes
•If there exist 30000 genes in the human genome
• Predict 50400 “3’ UTR variants”• Total of 80400 variants
•This assumes the ratio holds for all gene expression•Sage tag variants are a subset (3’utr) of splice variants
• 5’sage may expand the subset
Frequency of variants detected by SAGE
For all transcripts with count >=20 (15915 transcripts) from refseq, refseqX, refseqGS, and mgc
Novel gene discovery via SAGE
• 3519 tags occurred only in predicted transcripts– Intron and 3’utr locations indicate alternate splicing
• 150K (28%) tag types occurred only in the genome, not in transcripts– 9087(1.7%) with frequency > 10 and 24352(4.5%)
with frequency > 3– Would expect 2% polymorphism, except this is
inbred line?• 326K (60%) of tag types were unaccounted for
– 3450(0.6%) with frequency > 10, 13378(2.5%) with frequency > 3
– Sequence error, expectation is now known– Polymorphism, expect 2% of tag types, except this
is inbred line?– Spliced tags in novel transcripts, up to 6% of tag
types to be spliced
Many undiscovered transcripts exist, 2% at a moderate to high frequency, 10-15% at low frequency
Novel gene discovery via SAGE
• 3047 tags occurred only in predicted transcripts– Intron and 3’utr locations indicate alternate splicing
• 124K (36%) tag types occurred only in the genome, not in transcripts– 7022(2.0%) with frequency > 10 and 19155(5.5%)
with frequency > 3– Would expect 2% polymorphism, except this is
inbred line?• 162K (47%) of tag types were unaccounted for
– 641(0.2%) with frequency > 10 and 2384(0.7%) with frequency > 3
– Sequence error should be very low for non-singletons
– Polymorphism, expect 2% of tag types, except this is inbred line?
– Spliced tags in novel transcripts, up to 6% of tag types to be spliced
Many undiscovered transcripts exist, 2% at a moderate to high frequency, 10-15% at low frequency
Mouse Atlas 28 libraries after clustering tags
Detection of coding features
• N million tags representing N transcripts and at least N genes. (complexity)
• Distribution of transcript abundance (graph)
• coverage of refseq, MGC and unigene (complexity and breadth)
• N differentially expressed between any two stages at p < 0.001 (regulated)
• N not differentially expressed at p < 0.001 (housekeeping)
• N candidate new genes identified
• Genes that map, genes that don’t map, etc
• Quality of the data
Co-funding spent
Library construction rates
• Mouse libraries needed (May 04 – Feb 05).…………………….9.8 / mo
• Mouse libraries made (Oct 03 – Apr
04, excl. Dec 03)..…………6.2 / mo
• Mouse libraries made (Mar 04 – Apr 04)..………………………7 / mo
• All libraries made (Mar 04 – Apr 04)…………………………….9 / mo
• Most libraries made: (Oct 03, Mar 04)…………………………...10 / mo
02468
101214
J J A S O N D J
Month (June 2004-January 2005)
Nu
mb
er o
f T
issu
es
Libraries Made 52Libraries in Progress 5Tissues Waiting for Library Construction 17Tissues Collected (but not yet delivered) 12Tissues To Be Collected 64
Tissue Acquisition Pipeline
www.mouseatlas.org
cgap.nci.nih.gov
Training / Recruitment
Management
Detection and elimination of contamination
101 SAGE libraries built
101 SAGE libraries
Tags sequenced
Library Construction Scale-Up
0
2
4
6
8
10
12
Date (Month-Year)
Nu
mb
er l
ibra
ries
All libraries
Mouse
Rationale and Goals
Systematic association of expressed genes with precisely defined tissues sampled throughout development will enhance dramatically the mouse as a tool for developmental biologists and those seeking to understand the genetic basis of disease in murine models.
•To construct and sequence 150 SAGE libraries representing a variety of tissues and developmental stages
•To place these data in the public domain
ProgressObjective 1: Define the normal state for many tissues by determining…the number and identity of genes expressed throughout development.
•Progress: longSAGE library construction pipeline established! LCM tissue harvesting explored. Tech. D. on small samples well advanced. SAGELite and PCRSAGE libraries constructed. N SAGELite libraries constructed and sequenced by March 31, 2005. Trans-NIH group completed tissue harvesting for 90 adult tissues. Projected MPSS data in public domain before Fall 2004. Tag-to-gene mapping (v.1) complete at Vancouver. Mouse SAGE Genie under development (Hopkins / CGAP; G. Riggins PI).•Plan for completion: Continue at current rate with increasing emphasis on small, manually- and LCM-dissected samples.
Objective 2: Establish a data structure / curation strategy that will facilitate the ongoing collection of gene expression data….
•Progress: www.mouseatlas.org active and www.ncbi.nlm.nih.gov/ncicgap/ will soon host data (N libraries submitted to S. Greenhut and C. Schaeffer).•Plan for completion: Essentially complete. Data and annotation from Mouse Atlas and NIH /LYNX will populate databases.
Objective 3: Assemble gene expression profiles [to] test hypotheses related to technologies, tumor models and models of abnormal development.•Progress: N % complete. List models so far. Philosophy has been
to focus on establishing pipeline for wild-type tissues as these nay be most relevant to broader community. Increased focus on models over remainder of project.•Plan for completion: Construct, sequence and analyze N libraries representing specific models, including….
Detailed MilestonesYear 1• Establish the project management and communication system. COMPLETE• Launch of project web site in public domain. The launch will include a registration onthe website of all of the tissues we intend to include in the Atlas. COMPLETE• Complete dissections of type A tissues (See Table 1). INCOMPLETE• Complete experiments to compare the use of amplified and non-amplified RNA inSAGE library construction. COMPLETE• Complete experiments to compare the use of RNA from tissues isolated by LaserMicrodissection and by manual dissection in SAGE library construction. INCOMPLETE• Implement SAGE Bioinformatic processing pipeline. This includes implementation ofsoftware to automatically perform quality control testing on the sequencing of thetags, and entry of the tags into SAGEdb for subsequent analysis. COMPLETE• Expand SAGEdb to accommodate dissection procedures and digital images ofmouse tissues used to generate the SAGE libraries. WEBSITE• Construct and sequence 40 (30) SAGE libraries and enter them in the database. COMPLETEYear 2• Complete dissections of type B and C tissues (See Table 1). INCOMPLETE• Construct and sequence 80 (60) SAGE libraries and enter them in the database. IN PROGRESS• Web enabled data mining tool available for SAGE library comparisons. IN PROGRESS• Use of bioinformatics to identify differentially expressed genes from SAGE librariesfor further analysis and to assess the quality of the libraries generated. IN PROGRESSYear 3• Complete dissections of type D tissues and mouse models (See Table 1). INCOMPLETE• Construct and sequence 80 (60) SAGE libraries and enter them in the database. INCOMPLETE• Complete quantitative RT-PCR (QPCR) and in situ hybridization analysis for qualitycontrol and quality assurance. IN PROGRESS• Complete SAGE library construction, sequencing and analysis on mouse models to testutility of the database. IN PROGRESS• Demonstrate of the potential uses of the Atlas through SAGE analysis of specificmouse models. IN PROGRESS• Generate a spin-off project based on SAGE-based discoveries from mouse models(cancer models, early embryogenesis, or ‘fierce’ mice, see below). COMPLETE• Identify candidate genes not previously reported in mouse databases. IN PROGRESS• Target corporate partnership to build microarrays based on new candidate genes. INCOMPLETE• Present research discoveries based on the Atlas at scientific conference (e.g.Gordon Conference). IN PROGRESS• Publish dataset in peer-reviewed journals. IN PROGRESS
Established collaboration with NIH group to compare MPSSand SAGE and coordinate effort. LYNX efforts focused on adults; BC efforts focused on earlier developmental stages.
Mouse Atlas: SAGE Library Construction
Genome Sciences CentreBC Cancer Agency
11th May 2004
SAGE
LIBRARY
CONSTRUCTION
Agilent Bioanalyzer – RNA picochip, total RNA, 115 pg/uL
synthetic 25nt marker
PCR Optimization on 12% Polyacrylamide Gel
My Network Places/ mapper.ro on Xena/ GeneExpLab/ Typhoon Data/ LongSAGE folder/ Library Folder/ gel name_date
25
bp
La
dde
r (2
0 n
g/u
L)
23 cycles 25 cycles
25
bp
La
dde
r (2
0 n
g/u
L)
27 cycles 35 cycles
25
bp
La
dde
r (2
0 n
g/u
L)
25
bp
La
dde
r (2
0 n
g/u
L)
Bre
w o
nly
(Bre
w c
ontr
ol)
1/2
0 d
il N
o L
iga
se (
-’ve
co
ntr
ol)
1/1
0 d
il L
S C
ont
rol t
em
pla
te (
+’v
e c
ontr
ol)
1/2
0 d
il L
iga
tion
1/4
0 d
il L
iga
tion
1/8
0 d
il L
iga
tion
Bre
w o
nly
(Bre
w c
ontr
ol)
Bre
w o
nly
(Bre
w c
ontr
ol)
Bre
w o
nly
(Bre
w c
ontr
ol)
1/2
0 d
il N
o L
iga
se (
-’ve
co
ntr
ol)
1/2
0 d
il N
o L
iga
se (
-’ve
co
ntr
ol)
1/2
0 d
il N
o L
iga
se (
-’ve
co
ntr
ol)
1/1
0 d
il L
S C
ont
rol t
em
pla
te (
+’v
e c
ontr
ol)
1/1
0 d
il L
S C
ont
rol t
em
pla
te (
+’v
e c
ontr
ol)
1/2
0 d
il L
iga
tion
1/2
0 d
il L
iga
tion
1/4
0 d
il L
iga
tion
1/4
0 d
il L
iga
tion
1/8
0 d
il L
iga
tion
1/8
0 d
il L
iga
tion
125 bp
150 bp
200 bp
100 bp
75 bp
50 bp
25 bp
175 bp
131 bp Ditag
Load 5uL of Ladder
Load 5uL of sample
131bp Ditag on 12% Polyacrylamide Gel
My Network Places/ mapper.ro on Xena/ GeneExpLab/ Typhoon Data/ LongSAGE folder/ Library Folder/ gel name_date
Load 5uL of Ladder
Load 6 – 8 uL of sample per well
25bp Ladder(20ng/uL)
131 bpDitag
75 bp
100 bp
125 bp
150 bp
175 bp
200 bp
36bp Ditag on 15% Polyacrylamide Gel
My Network Places/ mapper.ro on Xena/ GeneExpLab/ Typhoon Data/ LongSAGE folder/ Library Folder/ gel name_date
25bp ladder
25bp Ladder
25 bp
50 bp
75 bp
100 bp
125 bp
150 bp
175 bp
200 bp
131 bpUncut Ditag
84 bp and 87 bpPartially cutDitag
44bp and 47bpAdaptor sequence
36 bp Ditag
Load 5uLLadder
Load 4 ul of sample per well
(20 ng/uL)(20 ng/uL)
Em
pty
lane
Em
pty
lane
Concatemer on 8% Polyacrylamide Gel
My Network Places/ mapper.ro on Xena/ GeneExpLab/ Typhoon Data/ LongSAGE folder/ Library Folder/ gel name_date
100 bp Ladder(10 ng/uL)Load 10 uL
100 bp Ladder(20 ng/uL)Load 5 uL
Load all 10 uL of concatemer into 1 well
100 bp
200 bp
300 bp
400 bp
500 bp
600 bp
700 bp
800 bp900 bp
1000 bp
100 bp
200 bp
300 bp
400 bp
500 bp
600 bp700 bp800 bp900 bp1000 bp
1500 bp
2072 bp
Small size fraction
Medium size fraction
Large size fraction
Colony PCR on 1.5% Agarose Gel
My Network Places/ mapper.ro on Xena/ GeneExpLab/ Typhoon Data/ LongSAGE folder/ Library Folder/ gel name_date
Small size fraction Medium size fraction Large size fractionNo DNA and No Ligase
-’ve controls
Load 1.5 uL of Sample per well
1 Kb+ Ladder(20 ng/uL)Load 1 uL
Library construction – future throughput & staffing
Bottom line : one 3’ most tag per transcript
Tissue and stage selection
150 libraries, 22 stages of development, 24 tissues, and tissue subtypes
Tissue selection, heart & lung
Theiler Stage 1 3 4 9 11 13 15 17 19 20 21 22 23 24 25 26 27Description 1 cell morula blast Neonates
days post coitum (dpc) 6.5 7.5 8.5 9.5 10.5 11.5 12.5 13.5 14.5 15.5 16.5 17.5 18.5Embryos
time post birth 1 2 3 4 5heart
whole bulbous cordisatriumatrio-ventricular cushionsventricle
lung
90 adult libraries to be produced using MPSS (Lynx) technology by a group at NHGRI led by Chris Austin
Discovery and Analysis
Data quality, error detection and correctionTag to gene mappingFunctional mappingDiscovery of novel features
Low frequency tags map poorly to genome and transcript resources
Tag Frequency
Proportion of tag types mapped
0
0.1
0.2
0.3
0.4
0.5
0.6
0.7
0.8
0.9
1
1 2 3 4 5 6-10 11-50 51-100 101-1000 >1000
Correction of sequence errors by clustering tags
• High frequency tags are correct• Single base changes in lower frequency tags are errors• A prediction of about 10% tags in error• Extrapolation vs PHRED quality scores yields 4.6% error• Library construction error (rt, pcr) was 5%• Apply this model to the full data set
Colinge & Feger, 2001
More tags map to exons
All tag types
Highly expressed tag types
5’
3’
73%
3.4% 1.6%
1.5% 9.9%
0.8%
1.4%
3. 1%
4.4%
5’
3’
25%
13% 5.2%
3.1% 8.4%
7.0%
18%
4.2%
15%
Conclusions
The mouse atlas is available, please start using it.
Tag errors can be accounted for in several ways
Tags map to all areas of the genome, which will lead to new feature discovery
Only a small proportion of splice variants are currently annotated.
Funding
• Genome Canada
• NCI
• NHGRI
• BC Cancer Agency
• Applied Biosystems
Steven JonesGenome Sciences Centre
Asim SiddiquiScott ZuyderduynRichard VarholDerek LeungKevin TeagueLisa LeeAnita Landry
Our Team
Elizabeth M. Simpson CMMT
Robert XieSlavita BohacecByron Kuo
Adrian BurkeGenomeBC
Caroline AstellProject Manager
Pamela HoodlessTerry Fox Laboratory
Jim RupertMona WuRebecca Cullum
Cheryl HelgasonCancer Endocrinology
Brad HoffmanTeresa Ruiz de
AlagaraIda Zhang
Marco MarraGenome Sciences Centre
Jaswinder KhattraAllen DelaneyJennifer AsanoSusanna Chan
Greg Riggins, JHUDaniela Gerhardt, NCIChris Austin, NHGRI
Tag location All 1 2 3 4 5 6 7 8 9 10 11-100 101-1000 >1000
exin 448 215 72 22 17 12 15 5 3 8 4 64 11 0
exin- 252 140 37 21 19 5 3 3 3 2 2 14 3 0
exon 32633 12825 4834 2354 1403 904 690 613 500 435 351 6202 1471 51
exon- 17629 8663 3199 1508 915 604 436 301 261 186 142 1342 70 2
inex 357 192 60 26 8 17 7 5 4 2 4 28 4 0
inex- 328 169 48 23 15 7 9 2 2 2 3 45 3 0
intergenic 20081 14139 2776 864 473 278 220 131 123 89 85 808 88 7
intron 24264 18085 3512 1029 484 273 163 122 95 63 49 355 29 5
intron- 9306 7253 1202 296 163 83 54 35 27 23 20 131 15 4
utr3 11175 4989 1658 798 448 372 267 185 162 143 127 1825 200 1
utr3- 6861 3711 1125 521 311 187 158 124 95 70 37 490 32 0
utr5 4190 2369 632 303 153 105 89 44 49 42 29 342 31 2
utr5- 5653 2924 883 377 241 158 115 84 67 49 53 639 62 1
Total: 133177 75674 20038 8142 4650 3005 2226 1654 1391 1114 906 12285 2019 73
Tag count All 1 2 3 4 5 6 7 8 9 10 11-100 101-1000 >1000
exin 0.34 0.28 0.36 0.27 0.37 0.40 0.67 0.30 0.22 0.72 0.44 0.52 0.54 0.00
exin- 0.19 0.19 0.18 0.26 0.41 0.17 0.13 0.18 0.22 0.18 0.22 0.11 0.15 0.00
exon 24.50 16.95 24.12 28.91 30.17 30.08 31.00 37.06 35.95 39.05 38.74 50.48 72.86 69.86
exon- 13.24 11.45 15.96 18.52 19.68 20.10 19.59 18.20 18.76 16.70 15.67 10.92 3.47 2.74
inex 0.27 0.25 0.30 0.32 0.17 0.57 0.31 0.30 0.29 0.18 0.44 0.23 0.20 0.00
inex- 0.25 0.22 0.24 0.28 0.32 0.23 0.40 0.12 0.14 0.18 0.33 0.37 0.15 0.00
intergenic 15.08 18.68 13.85 10.61 10.17 9.25 9.88 7.92 8.84 7.99 9.38 6.58 4.36 9.59
intron 18.22 23.90 17.53 12.64 10.41 9.08 7.32 7.38 6.83 5.66 5.41 2.89 1.44 6.85
intron- 6.99 9.58 6.00 3.64 3.51 2.76 2.43 2.12 1.94 2.06 2.21 1.07 0.74 5.48
utr3 8.39 6.59 8.27 9.80 9.63 12.38 11.99 11.19 11.65 12.84 14.02 14.86 9.91 1.37
utr3- 5.15 4.90 5.61 6.40 6.69 6.22 7.10 7.50 6.83 6.28 4.08 3.99 1.58 0.00
utr5 3.15 3.13 3.15 3.72 3.29 3.49 4.00 2.66 3.52 3.77 3.20 2.78 1.54 2.74
utr5- 4.24 3.86 4.41 4.63 5.18 5.26 5.17 5.08 4.82 4.40 5.85 5.20 3.07 1.37
Total: 100 100 100 100 100 100 100 100 100 100 100 100 100 100
Proportions of tag types
Count of tag types, mouse atlas
All tags and singletonsproportion by location
0.00
5.00
10.00
15.00
20.00
25.00
30.00
All
1
Proportion by tag locationselected tag frequency
classes
0.00
10.00
20.00
30.00
40.00
50.00
60.00
1
2
5
11-100
Mention sageLite and amplified libraries?
E9.5 primitive ventricle SAGE library68,270 tags; 15,496 tag
types
E9.5 atria SAGE library60,466 tags;
14,393 tag types
E9.5 bulbus cordis SAGE library
77,826 tags; 18,980 tag types
9.5 dpc heart (> 5 tags)
73
2141
141822
* significantly more or less frequent at P>0.05
040531ATLASSITE VISIT
LCM/BRAIN
SPECIFIC OVERHEA
DS
Relationship of Technologies
High-Quality RNA Sent to GSC
33% Compl
ete
Brain-Specific Advisory Team
Max Cynader, Ph.D.Director,
Brain Research Centre
Shiv Prasad, Ph.D.Research Associate,
Brain Research Centre
John O’Kusky, Ph.D.Core Leader & Assoc.
Prof.Department of Pathology
Anthony G. Phillips,
FRSC., Ph.D.Professor
Department of Psychiatry
Blair Leavitt,MD, CM, FRCP(C)Scientist & Assoc.
Prof.CMMT, UBC
Process Underlying Library Choices
Striatum Collaboration
Cortical Neurogenesis
50 Brain Biolog
yLibrari
es
?ADD TO PROJECT
WIDE SLIDES?
Collaborators (additional to pg. 22)
Blair R. Leavitt MD,CM, FRCP(C) (CMMT, UBC)Dr. Leavitt is a neurologist with both a clinical and research focus on degenerative disease. He is interested in expression profiling results for the striatum because of the key roll of that region in the development of Huntington Disease. He is ready and able to follow-up experimentally on striatum specific genes we identify.
Publications (additional to pg. 56)
Ongoing:Web publication during first 5.5 months of 2004. Ave. page views/month: 4090. Ave. downloads/library: 10
Abstract:Society for Neuroscience Meeting, San Diego, Oct. 23-27, 2004. SAGE libraries constructed from murine neural tissue harvested by laser capture microdissection (LCM). Xie, Y.-Y., Bohacec, S., Khattra, J., Lee, L., Delaney, A., Jones, S., Marra, M., and Simpson, E. M.
In preparation:??
Planned: Laser capture microdissection (LCM) adapted to construct SAGE-lite libraries from embryonic sites of neurogenesis. Xie, Y.-Y., Bohacec, S., Khattra, J., Lee, L., Delaney, A., et al., Jones, S., Marra, M., and Simpson, E. M. (200_). Journal of Neuroscience Methods.
Ocular dominance plasticity critical period expression profiled by SAGE, Affymetrics, and CodeLink. Cynader, M. S., Bohacec, S., Prasad, S. S., Dewell, S., Kuo, B., Kojic, L., Khattra, J., et al., Jones, S., Marra, M., Wasserman, W. W., and Simpson, E. M. (200_). Nature Neuroscience.
What next? (ideas - not an overhead)
eQTL focused on Disease Modifiers Couple large scale Affy chip technology and Strain-specific sequencing to
actually clone and identify the sequence differences of Quantitative Trait Loci (QTL) for traits or modifiers of mouse phenotypes (including such things as drug response, regulatory pathways, behaviour, and cancer susceptibility)
Subsection: Comparative SAGE libraries from mouse strains used to create the heterogeneous strains for QTL
Resources required at genomic level:mice, SAGE, Affy, sequencing, bioinformatics, genomic scanningAim: not just map but actually clone and find the specific bp change for ?# disease modifiers; and create a pipeline to do more
Background: The technology and throughput is finally here to achieve the identification of mouse QTLs. This has been a promising but unfruitful approach for years, which scientists and funding agencies (NIH, MRC) are recognizing the time may be here for correctly positioned multidisciplinary groups. Key are three recent developments: sequence of mouse genome, eQTL, start of mouse haplotype map.
Examples of Literature• Doerge, R. W. (2002). Mapping and analysis of quantitative trait loci in
experimental populations. Nat Rev Genet 3, 43-52.• Lemon, W. J., Bernert, H., Sun, H., Wang, Y., and You, M. (2002).
Identification of candidate lung cancer susceptibility genes in mouse using oligonucleotide arrays. J Med Genet 39, 644-55.
• Prows, D. R., McDowell, S. A., Aronow, B. J., and Leikauf, G. D. (2003). Genetic susceptibility to nickel-induced acute lung injury. Chemosphere 51, 1139-48.
PROBABLY NOT MAKE
OVERHEADS