56
RNA-seq analysis: From reads to differen6al expression Alicia Oshlack Murdoch Childrens Research Ins6tute @AliciaOshlack

RNA-seq analysis - Bioinformaticsbioinformatics.org.au/ws/wp-content/uploads/sites/... · Collaborave analysis and methods development Transcriptomics Epigenomics Genomics Clinical

  • Upload
    others

  • View
    12

  • Download
    0

Embed Size (px)

Citation preview

Page 1: RNA-seq analysis - Bioinformaticsbioinformatics.org.au/ws/wp-content/uploads/sites/... · Collaborave analysis and methods development Transcriptomics Epigenomics Genomics Clinical

RNA-seqanalysis:Fromreadstodifferen6alexpression

AliciaOshlackMurdochChildrensResearchIns6tute

@AliciaOshlack

Page 2: RNA-seq analysis - Bioinformaticsbioinformatics.org.au/ws/wp-content/uploads/sites/... · Collaborave analysis and methods development Transcriptomics Epigenomics Genomics Clinical

The current MCRI bioinformatics team •  Dr Nadia Davidson •  Dr Anthony Hawkins •  Dr Jovana Maksimovic •  Dr Katrina Bell •  Dr Belinda Phipson •  Dr Simon Sadedin •  Harriet Dashnow •  Luke Zappia •  Rebecca Evans

PhDposi6onsavailable

Page 3: RNA-seq analysis - Bioinformaticsbioinformatics.org.au/ws/wp-content/uploads/sites/... · Collaborave analysis and methods development Transcriptomics Epigenomics Genomics Clinical

MCRIBioinforma6csCollabora6veanalysisandmethodsdevelopment

Transcriptomics Epigenomics Genomics ClinicalGenomics

•  RNA-seq•  miRNA-seq•  Differen6al

expression•  Cancer•  Non-model

organisms•  Alterna6ve

splicing•  Singlecell

RNA-seq

•  Methyla6onarrays

•  Bisulfitesequencing

•  Histonemodifica6ons

•  ChIP-seq

•  Exomeanalysis

•  WGS•  Targeted

capture•  SNPs•  CNV•  Tandem

repeats

•  Clinicalexomes

•  TumourRNA-seq

Page 4: RNA-seq analysis - Bioinformaticsbioinformatics.org.au/ws/wp-content/uploads/sites/... · Collaborave analysis and methods development Transcriptomics Epigenomics Genomics Clinical

RNA-seqanalysis

Page 5: RNA-seq analysis - Bioinformaticsbioinformatics.org.au/ws/wp-content/uploads/sites/... · Collaborave analysis and methods development Transcriptomics Epigenomics Genomics Clinical

Genesandtranscripts

Gene

transcript

SlidefromAliciaOshlack

Page 6: RNA-seq analysis - Bioinformaticsbioinformatics.org.au/ws/wp-content/uploads/sites/... · Collaborave analysis and methods development Transcriptomics Epigenomics Genomics Clinical

RNA-seq

Pepkeetal,NatureMethods,2009

Page 7: RNA-seq analysis - Bioinformaticsbioinformatics.org.au/ws/wp-content/uploads/sites/... · Collaborave analysis and methods development Transcriptomics Epigenomics Genomics Clinical

Twowaystolookatsequencingdata

Sequenceof(mapped)read• genomesequencing• variantdetec6on• genomicrearrangements• Bisulfite-seq(methyla6on)• RNAedi6ngetc.

Posi6onofmappedread• RNA-seq• ChIP-seq• MeDIP-seqforDNAmethyla6onetc.

7

Page 8: RNA-seq analysis - Bioinformaticsbioinformatics.org.au/ws/wp-content/uploads/sites/... · Collaborave analysis and methods development Transcriptomics Epigenomics Genomics Clinical

TwowaystolookatRNA-seqdata

Sequenceof(mapped)read• Assembly• Determininggenes/transcripts

Posi6onofmappedread• Expressionlevels• Differen6alexpression

8

Page 9: RNA-seq analysis - Bioinformaticsbioinformatics.org.au/ws/wp-content/uploads/sites/... · Collaborave analysis and methods development Transcriptomics Epigenomics Genomics Clinical

Rawdata(fastqfiles)

•  Shortsequencereads•  Qualityscores

@HWI-ST1148:308:C694RACXX:5:1101:1768:1990 1:N:0:CGTACG NTAGGCCTTGGCAGTTTTGGAGAATCACTGCTGCCAAAGAGTCTACTTGG + #0<FFFFFFFFFFIIIIIIIIIIIIIIIIIIIIIIIIIIIIFFIIIIIII @HWI-ST1148:308:C694RACXX:5:1101:3409:1990 1:N:0:CGTACG NAGTTACCCTAGGGATAACAGCGCAATCCTATTCTAGAGTCCATATCAAC + #000BFBFFFFFFF<BFFFFBBBBBFBBFF<<FBFFIBFFFBFFFIIBFF

50bpsequence

Page 10: RNA-seq analysis - Bioinformaticsbioinformatics.org.au/ws/wp-content/uploads/sites/... · Collaborave analysis and methods development Transcriptomics Epigenomics Genomics Clinical

Differen6alexpression•  Whichgenesarechangingexpressionlevelbetweensamples?–  treatedvsuntreated,–  diseasevsnondisease,–  earlyvslate6mepoints,–  cellsinoneenvironmentvsanotherenvironment,–  etc,…

•  Thousandsofgenesbutonlyafewsamples–  Sophis6catedsta6s6calmethodsarerequiredforanalysis

Page 11: RNA-seq analysis - Bioinformaticsbioinformatics.org.au/ws/wp-content/uploads/sites/... · Collaborave analysis and methods development Transcriptomics Epigenomics Genomics Clinical

RNA-seqanalysisstepsRawsequencereads

Mapontogenome

Summarizereadstotranscripts

Sta6s6caltes6ng:Determinedifferen6allyexpressedgenes

Systemsbiology

DenovoassemblyAnnota6onbased Genomeguidedassembly

Whichtranscriptome?

Page 12: RNA-seq analysis - Bioinformaticsbioinformatics.org.au/ws/wp-content/uploads/sites/... · Collaborave analysis and methods development Transcriptomics Epigenomics Genomics Clinical

RNA-seqanalysisstepsRawsequencereads

Mapontogenome

Summarizereadstotranscripts

Sta6s6caltes6ng:Determinedifferen6allyexpressedgenes

Systemsbiology

DenovoassemblyAnnota6onbased Genomeguidedassembly

Whichtranscriptome?

Page 13: RNA-seq analysis - Bioinformaticsbioinformatics.org.au/ws/wp-content/uploads/sites/... · Collaborave analysis and methods development Transcriptomics Epigenomics Genomics Clinical

Mappingreadstothegenome•  Wheredothemillionsofshortsequencescomefrominthegenome?

•  Sequencingtranscripts,notthegenome

CDS CDS CDS CDS

CDS CDS CDS CDS

Gene

transcript

Page 14: RNA-seq analysis - Bioinformaticsbioinformatics.org.au/ws/wp-content/uploads/sites/... · Collaborave analysis and methods development Transcriptomics Epigenomics Genomics Clinical

Lotsofgoodalignershandlesplicejunc6onswell(e.g.TopHat,Star)

Exon1 Exon2

Page 15: RNA-seq analysis - Bioinformaticsbioinformatics.org.au/ws/wp-content/uploads/sites/... · Collaborave analysis and methods development Transcriptomics Epigenomics Genomics Clinical

RNA-seqdatainIGV

Page 16: RNA-seq analysis - Bioinformaticsbioinformatics.org.au/ws/wp-content/uploads/sites/... · Collaborave analysis and methods development Transcriptomics Epigenomics Genomics Clinical

Whichtranscriptometouse?

Page 17: RNA-seq analysis - Bioinformaticsbioinformatics.org.au/ws/wp-content/uploads/sites/... · Collaborave analysis and methods development Transcriptomics Epigenomics Genomics Clinical

Rawsequencereads

Mapontogenome

Summarizereadstotranscripts

Sta6s6caltes6ng:Determinedifferen6allyexpressedgenes

Systemsbiology

RNA-seqanalysissteps

DenovoassemblyAnnota6onbased GenomeguidedassemblyWhichtranscriptome?

Page 18: RNA-seq analysis - Bioinformaticsbioinformatics.org.au/ws/wp-content/uploads/sites/... · Collaborave analysis and methods development Transcriptomics Epigenomics Genomics Clinical

Op6on1

•  Useannota6on(knowngenes)– Workswellforwellstudiedorganisms(human,mouse,arabidopsis,drosophila,…)

– onlyasgoodasyourannota6on– Nonoveltranscriptsareanalysed

Page 19: RNA-seq analysis - Bioinformaticsbioinformatics.org.au/ws/wp-content/uploads/sites/... · Collaborave analysis and methods development Transcriptomics Epigenomics Genomics Clinical

Op6on2:Genomeguidedtranscriptassembly

•  Usestheloca6onanddensityofreadsalongthegenometoassembletranscripts

•  E.g.Cufflinks

•  Can’tassembleacrossbreaksinthegenome– Cancer,poorgenomes

Page 20: RNA-seq analysis - Bioinformaticsbioinformatics.org.au/ws/wp-content/uploads/sites/... · Collaborave analysis and methods development Transcriptomics Epigenomics Genomics Clinical

Op6on3:Denovotranscriptomeassembly

•  Assembletranscriptsfromthedatawithoutusingareferencegenome

•  “Harder”thangenomeassembly–  Ordersofmagnitudevaria6onincoverage–  Con6gsareshort–  Alterna6veisoforms/transcriptshaveoverlappingsequences–  *Very*computa6onallyintensive

•  Sokwareincludes –  Trinity–  Oases(velvet)–  TransAbyss–  …

Page 21: RNA-seq analysis - Bioinformaticsbioinformatics.org.au/ws/wp-content/uploads/sites/... · Collaborave analysis and methods development Transcriptomics Epigenomics Genomics Clinical

Example:Annota6ngthechickenWchromosome

ZZ ZW

Male Female

Twohypothesesformechanismsofaviansexdetermina6on:1.  DominantovarydetermininggeneonW(cfmammals)2.  DosageofZ-linkedgenes

Page 22: RNA-seq analysis - Bioinformaticsbioinformatics.org.au/ws/wp-content/uploads/sites/... · Collaborave analysis and methods development Transcriptomics Epigenomics Genomics Clinical

Thereisanannotatedchickengenome

•  ChickenWchromosomeispoorlyassembled•  AregenesonotherchromosomesreallyontheW,inpar6culartherandomchromosome?

Chromosome Assembled Size (Mb)

Size inc. random (Mb)

Estimated Size (Mb)

Estimated Genes

(Ensembl) Z 69 70 80 796

W 0.24 0.89 18-54 46

Un_random 56 - - 1287

Page 23: RNA-seq analysis - Bioinformaticsbioinformatics.org.au/ws/wp-content/uploads/sites/... · Collaborave analysis and methods development Transcriptomics Epigenomics Genomics Clinical

Experimentaldesign

PCRSexing

+12hourBlastoderms

HandplateforPCRSexing

RNA

Stage26pairedgonads(day4.5)

12Female

RNA

16Femalegonads

PooledSamples

12Female

16Femalegonads

12Male

12Male

16Malegonads

16Malegonads

RNA-seq• IlluminaHiSeq2000• Paired-end100bp• 4lanes• >80millionreads/sample

Page 24: RNA-seq analysis - Bioinformaticsbioinformatics.org.au/ws/wp-content/uploads/sites/... · Collaborave analysis and methods development Transcriptomics Epigenomics Genomics Clinical

Definingthetranscriptome

•  Annota6on~20,000genes•  Genomeguidedassembly(Cufflinks)~45,000genes

•  Denovotranscriptomeassembly~2.5milliontranscripts(Abysswithfiltering)!

Acombinedapproach•  Assemblecufflinkgenesusingtranscriptsfromourdenovoassembly

Page 25: RNA-seq analysis - Bioinformaticsbioinformatics.org.au/ws/wp-content/uploads/sites/... · Collaborave analysis and methods development Transcriptomics Epigenomics Genomics Clinical

Annota6onofthechickenWcombinedallthreeapproaches

W/W_random ChromsomeUn_random ChromosomeAutosomes

Blastoderm CoverageGonads Coverage

Abyss TranscriptsCufflinks TranscriptsEnsembl Transcripts

1000 1500 2000 2500 3000 3500

base position

039

1

Coverage

Genome

EnsemblCufflinks

AbyssRASA1−W

1400 1600 1800 2000 2200

base position

012

6

Coverage

Genome

EnsemblCufflinks

AbyssST8SIA3−W

2000 2200 2400 2600 2800

base position

069

9

Coverage

Genome

EnsemblCufflinks

AbyssGOLPH3−W

0 500 1000 1500 2000 2500

base position

019

4

Coverage

Genome

EnsemblCufflinks

AbyssZSWIM6−W

0 200 400 600 800 1000 1200 1400

base position

082

Coverage

Genome

EnsemblCufflinks

AbyssNEDD4−like−W

FulllistofWgenes/transcriptsfordifferen6alexpressionAyersetal,2013

Page 26: RNA-seq analysis - Bioinformaticsbioinformatics.org.au/ws/wp-content/uploads/sites/... · Collaborave analysis and methods development Transcriptomics Epigenomics Genomics Clinical

RNA-seqanalysisstepsRawsequencereads

Mapontogenome

Summarizereadstotranscripts

Sta6s6caltes6ng:Determinedifferen6allyexpressedgenes

Systemsbiology

DenovoassemblyAnnota6onbased Genomeguidedassembly

Whichtranscriptome?

Page 27: RNA-seq analysis - Bioinformaticsbioinformatics.org.au/ws/wp-content/uploads/sites/... · Collaborave analysis and methods development Transcriptomics Epigenomics Genomics Clinical

Summariza6on

Takeyour“transcriptome”andaddupthereads

Page 28: RNA-seq analysis - Bioinformaticsbioinformatics.org.au/ws/wp-content/uploads/sites/... · Collaborave analysis and methods development Transcriptomics Epigenomics Genomics Clinical

Coun6ngoverexonsvscoun6ngovergenes

Exon1 Exon2

Exon1=8readsExon2=10reads

Coun6ngoverwholegene(Exon1+Exon2)=15

Page 29: RNA-seq analysis - Bioinformaticsbioinformatics.org.au/ws/wp-content/uploads/sites/... · Collaborave analysis and methods development Transcriptomics Epigenomics Genomics Clinical

Non-modelorganismsDenovotranscriptomeassembly

1.  Clusterassembledcon6gsinto“genes”(independentoftheassembler)

2.  Performreadcoun6ngpercluster

Corset Ourmethod

Davidson&Oshlack,GenomeBiology,2014

Page 30: RNA-seq analysis - Bioinformaticsbioinformatics.org.au/ws/wp-content/uploads/sites/... · Collaborave analysis and methods development Transcriptomics Epigenomics Genomics Clinical

Summariza6onturnsmappedreadsintoatableofcounts

**veryhighdimensionaldata**

TagID A1 B1ENSG00000124208 478 4830

ENSG00000182463 27 48

ENSG00000125835 132 560ENSG00000125834 42 131ENSG00000197818 21 52ENSG00000125831 0 0ENSG00000215443 4 9ENSG00000222008 30 0ENSG00000101444 46 54ENSG00000101333 2256 2702

… …tensofthousandsmoretags…

Page 31: RNA-seq analysis - Bioinformaticsbioinformatics.org.au/ws/wp-content/uploads/sites/... · Collaborave analysis and methods development Transcriptomics Epigenomics Genomics Clinical

RNA-seqanalysisstepsRawsequencereads

Mapontogenome

Summarizereadstotranscripts

Sta6s6caltes6ng:Determinedifferen6allyexpressedgenes

Systemsbiology

DenovoassemblyAnnota6onbased Genomeguidedassembly

Whichtranscriptome?

Page 32: RNA-seq analysis - Bioinformaticsbioinformatics.org.au/ws/wp-content/uploads/sites/... · Collaborave analysis and methods development Transcriptomics Epigenomics Genomics Clinical

Summariza6onturnsmappedreadsintoatableofcounts

**veryhighdimensionaldata**

TagID A1 B1ENSG00000124208 478 4830

ENSG00000182463 27 48

ENSG00000125835 132 560ENSG00000125834 320 131ENSG00000197818 21 52ENSG00000125831 0 0ENSG00000215443 4 9ENSG00000222008 30 0ENSG00000101444 46 54ENSG00000101333 2256 2702

… …tensofthousandsmoretags…

Page 33: RNA-seq analysis - Bioinformaticsbioinformatics.org.au/ws/wp-content/uploads/sites/... · Collaborave analysis and methods development Transcriptomics Epigenomics Genomics Clinical

Whichgenesaredifferen6allyexpressed?

•  LikeanyotherexperimentRNA-seqneedstobereplicatedsowecangetameasureofvariance

Page 34: RNA-seq analysis - Bioinformaticsbioinformatics.org.au/ws/wp-content/uploads/sites/... · Collaborave analysis and methods development Transcriptomics Epigenomics Genomics Clinical

Replica6onisessen6al

TagID A1 A2 A3 B1 B2 B2ENSG00000124208 478 619 559 4830 7165 6651

ENSG00000182463 27 20 18 48 55 56

ENSG00000125835 132 290 450 560 408 266ENSG00000125834 320 462 355 131 99 91ENSG00000197818 21 29 23 52 44 65ENSG00000125831 0 0 0 0 0 0ENSG00000215443 4 4 4 9 7 3ENSG00000222008 30 23 23 0 0 0ENSG00000101444 46 63 55 54 53 52ENSG00000101333 2256 2793 2931 2702 2976 2226

… …tensofthousandsmoretags…

**veryhighdimensionaldata**

Page 35: RNA-seq analysis - Bioinformaticsbioinformatics.org.au/ws/wp-content/uploads/sites/... · Collaborave analysis and methods development Transcriptomics Epigenomics Genomics Clinical

Qualitycontrol–checkyourdata!

DatafromAndrewElefanty

Sortedcellpopula6ons

Page 36: RNA-seq analysis - Bioinformaticsbioinformatics.org.au/ws/wp-content/uploads/sites/... · Collaborave analysis and methods development Transcriptomics Epigenomics Genomics Clinical

Dataexplora6on

Page 37: RNA-seq analysis - Bioinformaticsbioinformatics.org.au/ws/wp-content/uploads/sites/... · Collaborave analysis and methods development Transcriptomics Epigenomics Genomics Clinical

Sta6s6caltestsfordifferen6alexpression

TagID A1 A2 A3 B1 B2 B2ENSG00000124208 478 619 559 4830 7165 6651

ENSG00000182463 27 20 18 48 55 56

ENSG00000125835 132 290 450 560 408 266ENSG00000125834 320 462 355 131 99 91ENSG00000197818 21 29 23 52 44 65ENSG00000125831 0 0 0 0 0 0ENSG00000215443 4 4 4 9 7 3ENSG00000222008 30 23 23 0 0 0ENSG00000101444 46 63 55 54 53 52ENSG00000101333 2256 2793 2931 2702 2976 2226

… …tensofthousandsmoretags…

**veryhighdimensionaldata**

Page 38: RNA-seq analysis - Bioinformaticsbioinformatics.org.au/ws/wp-content/uploads/sites/... · Collaborave analysis and methods development Transcriptomics Epigenomics Genomics Clinical

•  Normalisa6on–  Librarysize(sequencingdepth)

•  IncludeasoffsetinGLM•  Scalingnormalisa6on(sizefactors)

–  Composi6onbias(TMM)–  Batcheffects(RUVSeq)

Thingstothinkaboutbeforesta6s6caltes6ng

.

(a)

log2(Kidney1 NK1) − log2(Kidney2 NK2)

Den

sity

-6 -4 -2 0 2 4 6

0.0

0.4

0.8

log2(Liver NL) - log2(Kidney NK)

Den

sity

-6 -4 -2 0 2 4 6

0.0

0.2

0.4(b)

●●

●●

●●

●●

●●

●●

●●

●●

● ●

●●●

●●

●●

●●

●●

●●

●●

●●

●●

●● ●

●●

●●

●●

● ●●

● ●

●●

●●

●●

●●

●●

●●●

● ●●

●●

●●

●●

● ●●

● ●●

●●

●●

●●

●●

●●

● ●

●●

● ●

●●

●●

● ●

●●

●●

●●

●●

●●

●●●

●●

●●

●●

●●

●●

●●

● ●

●●

● ●

●●

● ●

●●

● ●

●●

● ●

●●

●●

●●

● ●●

●●

●●

●●

● ●●

●●

●●

●●

●●

●●

●●

●●

● ●

●●

●●●

● ●

●●

●●

● ●

●●

●●

●●

●●

●●

●●

●●

● ●●

●●

●●

● ●

●●

●●●

●●

● ●

● ●

●●

●●

●●●

●●

●●

●●

●●

●●

●●

●● ●

● ●

●●

●●

● ●

● ●

●●

●●

●●

●●

●●

●●

● ●

●●

●●

● ●

● ●●

●●

●● ●

●●

●●●

● ●

●●

●●●

●●

●●

●●

●●

●●

●●

●●

●●

●●●

●●

●●

●●

● ●● ●

●●

●●

●●

●●

●●

●●

● ●

●●

● ●

●●

● ●

●●

●●

● ●

●●

●●

●●

●● ●●

●●

●●

●●

●●

●●

●●

●●

●●

●●

●●

●●

● ●

●● ●●●

●●

● ●

●●

●●

●●

●●

● ●

●●

●●

●●

● ●

●●

●●

●●

● ●

● ●

●●● ●

●●

●●

●●

● ●

●●

● ●

●●

●●

● ●

●●

● ●

●● ●

● ●

●●

●●

●●

● ●●

●●

●●

●●

●●

●●

●●

● ●

● ●

● ●

●●

●● ●

●●

● ●

●●

● ●

●●

●●

●●

●●

●●

●●

● ● ●

● ●

● ●●

● ● ●

●●●

●● ●

●●

●●

● ●

●●

●●

●●

●●

● ●

●●

●●

● ●

●●

●●

● ●

●●

●●

●●

●●

● ●●

●● ●

●●

●●

● ●●

●●

●●

●●

● ●

●●

●●

●●

●●

● ●●

● ●

●●

●●

●●

●●

● ●

● ●

●●

●●

●●

●●●●

● ●

●●

●●

●● ●●

● ●

●●

●●

●●●

●●●

● ●

●●

● ●

●●

●●

● ●●

●●●

●●

●●

●●

●● ●●

● ●●

●●

●●

●●

●●

●●

●● ●

●●

●●●

●●

●●

●●

●●

● ●

●●

●●●

●● ●●● ● ●

●●●

●●

●● ●

● ●

● ●

●●●

● ●

● ●

●●

●●

●●

●●

●●

●●

●● ●

● ●

●●

●●

●●

● ●

● ●

●●

●●

● ●

● ●

●●

●● ● ●

●●

●●

●●

●●

●●

●●

●●

● ●● ●

● ●●

● ●●

●● ●

● ●

●●

●●

●●

●●

●●

●●

● ●

●●

● ●

●●

● ●

● ●

●●

●●

● ●

●●

● ●

●●

●●

● ●●

●●

●●

● ●●

● ●

●●

●●

●●

●●

● ●

●●

● ●

●●

●●●

●●●

●●

●●

●●

●●

●●

●●

●●●

●● ●

●●

●●

●●

●●

●●

●●

●●

●●

●●

● ●

●●

● ●

●●

●●

●●

●●

●●

●●

● ●●

●●

●●●

●●●

●●

● ●

●●

●●

●●

●●

●●

●●

●●

●●

●●

●●

●●

●●

●●

●●

● ●

●● ●

●●

●●

● ●

●●

●●

●●

● ●

●●

● ●

●●

● ●

●●

●●

●●

● ●

●●

● ●

● ●

●●

●●

● ●

●●

● ●

●●

●● ●

●●●●

●●●

●●

●●

●●

● ●

●●

●●

● ●●

● ●

●● ●●

●●

●●

●●

● ●

●●

●●

● ●

● ● ●

●●

●●

● ●●

●●

●●● ●

●●

●●

● ●

●●

●●

●●

●●

●●

●● ●

●●

●●●

●●●●

●●

● ●

●●

●●● ●

●●

●●

●●

●●

● ●

●●

●●

●●

● ●

●●

●●

●●

●●

●●

● ●

●●

●●

●●

●●

●●●

● ●

●● ●

● ●●

●●

●●

● ●

●●

●●

●●

●●

●●

●●

●●

●●

●●● ●

●●

●●

●●

●●

●●

●●

●●●

●●

●●

●●●

● ●

●●

●● ●

●●

●●

● ●

●●●

● ●●

●●

● ●

●●

●●

●●

●●

●●

● ●

●●

● ●

●●

●●

● ●●

●●

●●

●●

●●

●●●

●● ●

● ●

● ●●

●●

●●●

●●

●●

●●

●●

●●

●●

● ●

●●

●●

●●

●●

●●

● ●●

● ●

●●

● ●

●●

●●

● ●

●●

● ●

●●

●●

●● ●●

●●

●●

●●

●●

●●

● ● ●●

●●

●●

●●

● ● ●●

●●

● ●

●●

●●

● ●

●●

● ●

●●

●●

● ●

●●

●●

● ●●

●●

●● ●

●●

●●

●●

●●

●●

●●

●●

●●

●●●●

●●

●●

●●

●●

●●

●●

●●

●●

●●

●●

● ●

●●

●●

●●

● ●

●●

●●

● ●

●●●●

●●

●● ●

●●

●●

●● ●●

●●

●●

● ●●

● ●

●●

●●

●●

●●

●●

● ●●

●●

● ●●

● ●●

●●

●●

●●

● ●

●●

●●

●●

●● ●●

●●

●●

●● ●

●● ●

● ●

●●

●●

●●

● ●

●● ●

●●

● ●●

● ●

●●

●●

● ● ●

●●

●●

●●

●●●

●●

●●

●●

●●

● ●

●●

●●

● ● ●

● ●

●●

●●

●●

●●

●●

● ●

● ●●

●●

● ●

●●● ●● ●

●●

●●

●●●

●●●

●●

●●

●●

●●●

●●

● ●

● ●

●●

●●

●●

●●●

● ● ●

●●

●●

●●

●● ●

●●●

● ●

●●●

●●

● ●●

●●

●●

● ●●

●●●●●

●●●

●●

●●

●●●

●●

●●

●●

● ●

●●

● ●

●●

●●

●●

●●

●●

●●

● ●

●●

●●

●●

●●

●●

●●

●●

●●

●●

●● ●

●●

●●

● ●

●●

● ●

●●

●●

●●

●●

●●

●●

●●

●●

●●

●●

●●

●●

●●

● ●●

●●

● ●●

● ●

● ●

●●●

● ●●

● ●

●●

● ●

●●

●●

●●

●●

● ●

● ●

● ●

●●

●●

●●

● ●

● ●

●●

●●

●● ●

●●

●●

●●

● ●● ●

● ●●

●●

●●

●●

● ●

●●

●●

●●

● ●

●●

●●

●●●

●●●

●●

●●

●●

●●

●●

●●

●●

●●

●●

●●

● ●

●●

●●

●●

●●

●●

● ●

●●

●●

●●

●● ●

●●

●●

●●

●●

●●●

●●

●●

● ●

●●

●●

●●

●●

●●

●●

●●

●●

●●

●●●

● ●

● ● ●

●●

●●

●● ●

●●

●●

●●

● ●

●●

●●

●●

● ●

●●

● ●

●●●

●●

●●

● ●

●●

●●

●●

●●

●●

● ●

●●

● ●●

● ●

● ●●

●●

●●

● ●●

●●

● ●

● ●

●●

●●

●●

●●

●●

●●

●●

●●●

●●

●●

●●

●●●

●●

●●

●●

●●

●●

●●

●●

●●

●●

●●

●●

●●●

●●

● ●

●●

●●

●●

●●

●●

●●

● ●●

●● ●●

●●

●●

●●

●●

●●

●●

● ●●

●●● ●

● ●

●●

●●

●●

● ●

●●

●●● ●

●●

● ●

●●

●●

●●

●● ●●●

●●

●●

●●

● ●

●●

●● ●

● ●●

●●

●●

●● ●

●●●●

●●

●●

● ●

●●

●●

●●

●●

●●

●●

●●

●●

●●●

● ●

●●

●● ●

● ●

●●

●●

●●

●●

● ●

● ●

●●

●●

●●

●●

●●

● ●●

●●

●● ●

●●

●●

●●

●●

● ●

●● ●●

●●

● ●

● ●

● ●

●●●

●●●

● ●

●●

● ●

●●

● ●

●●

●●

●● ●

● ●

●●

●●● ● ●

●●

●●

● ●

●●

● ●

●●

●●

●●

●●●

●●

●●

●●● ● ●●●

●●

● ●●

●●●

● ● ●●

●●

●●

●●●●

●●

●● ●

●●

●●

● ●●

●●

●●●●

● ●●●

●●

●●

●●

●● ●

● ●●

●●

●●

●●

●●

●●●

● ● ●

●●

●●

● ●

●●

● ●

●●

●●●

●●

●●

●●

●●

●●

●●●

●●

● ●

●●

● ●

●●●

●●

● ●

●●

●●

● ●

●●

●●

●●

● ●

●●

● ●

●●

● ●

●●

●● ●

●●

●●

●●

●●

● ●

●●

●● ●

●●

●●

●●

●●

●●

●●

●●

●●

●●

●●

●●●

●●

● ●

● ●

● ●

● ●●

●●

●●

● ●

●●

●●

●●

●●

●●●

●●

●●

●●●

●●

●●

●●

●●

●●

●●

●●

●●

●●

●●

●●

●●

●●

●● ●

●●

●●

●●

●●

●●

● ●

●●

●●

●● ●

● ●

●●

●●

●●

●●

●●

●● ●●● ●

● ●

● ●

●●●

● ●

●●

●●

●●

● ●●●

●●●●

●● ●

● ● ●

●● ●

●●

●● ●

●●

●●

●●

●●

●●●●

● ●

● ●●

● ●

●●

●●

●●

●●

●●

●●

●●

●●

●●

●●

●●●

●●

●●

●●

●●

●●

●●

●● ●

●●●

● ● ●●

●●

●●

●●

●●

●● ●

●●

●●

●●

●●

●● ●

● ●

●●

●●

●●

●●

●●

●●

●●

●●

●●

●●

●●

●●

● ●●

●●

●●

●●

●●

● ●

●●

● ●

●●

●●

●●

●●

●●

●● ●

●●●

●●

●●

●●

● ●

●●

●●

●●

●● ●

●● ●

●●

●●

● ●●

●●

●●

●●

● ●●

●●

●●

●●

●●

●●●

●●

● ●

● ●

●●

●●

●●●

●●

● ●

●●●

●●

●●

●●

●●

● ●●

● ●

●●

●●

●●

●●

●●

● ●

●●

●●

● ●

●●

●●

● ●

●●

● ●

●●

● ●

●●

●●

●●

●●

●●

● ●

● ●

●●

● ●

● ●

●● ●

●●

●●

●●

●●

●●

●●

● ●

●●

● ●

●●

● ●

● ●

●●●●

●●

●●

●●

●●

●●

●●●

● ●

●●

●●

●●

●●

● ●

●●

●●

● ●

●●

●●

●●

●●

●●

● ●

●●

●● ●

●●

●●

●●

● ●

●●

●●

●●

● ●

●●

●●

●●

● ●●

●●

●●

●●

●●

●●

●●

●●

● ●

●●

●●

●●

●●

●●

●●

● ●

●●

●●●

●●

●●●

● ●

●●

●●●

●●

●●

●●

●●

●●

● ●

●●

●●

●●

● ●

● ●

●●

●●

●●

●●

●●

●●

●●

●●

●●

● ●●

●●

●●

●●

●●

●●

●●

●●

●●

●●

●●

●●

●●

●●

●●●

●●

●●

●●

●●

●●

●●

●●

●●

●●

● ●●●

●●

●●

●●

●●

● ●

●●

●●

●●

●●

●●

●●

●●●

●●

●●

● ●

●●

●●

●●

●● ●

●●

●●

● ●

● ●

●●

●●

● ●

● ●

●●

●●

●●

●●

● ●

● ●

●●●

●●

●●

●●

●●

●● ●

●●

● ●

●●

●●

● ●

●●

●●

● ●

● ●

●●●

●●

●●

●●

●●

● ●●

● ●

●●

●●●

●●

● ●

● ●

●●

● ●

●●

●●

●●

●● ●

●●

●●

● ●

●●

●●

●●

●●● ●

●●

●●

●●

●●

●●

●● ●

●●

●●

●●

●●

● ●

●●

●●

● ●

●●

●●

●●

●●

● ●

●●

●●

●●

●●

●●

●●

●●

●●

● ●

● ●

●●●

●●

●●

● ●

● ●

●●

●●

● ●

●●

●●●●

●●

●●

●●

●● ●

● ●

●●

●● ●

●●

● ●

●●

●●●

●●

●●

● ●

●●

●●

● ●

●●

●●

●●

●●

●●

●●

●●

●●

●●

●●

● ●

●●

● ●

●●

● ●

●●

●●

●●

● ●

●●

● ●

●●

●●

●●

●●

●●

● ●

●●

●●

●●

●●

●●

●● ●

●●

●●

●●●

●● ●

●●

●●

●●

●●

●●

●●

●●

●●

● ●

●●

●●

●●

●●

● ●

● ●

●●

● ●

●●

●●

●●

●●

●●

●●

●●

●●

●●

●●

●●

●●

● ●

●●

●●

●●

● ●

●●

●●

●●

●●

● ●

●●

●●

●●

●●

●●

●●

●●

●●

●●

● ● ●

●● ●

●●

●●

● ●● ●

●●

●●

●●

● ●

●●

●●

●●

●●

●●

● ●

●●

●●

●●

● ●

● ●●

●●

●●

●●

●●

● ●

●●●

●●

● ●

●●

●●

●●

● ●

● ●

●●

●●

●●

● ●

●●

● ●

●●●

●● ●

● ●●

●●

●●

●●

● ●

●●

●●

●●

●●

●●

● ●

●●

●●

●●

● ●

●●●

●●

●●

●●

●●

●●

●●

●●

●●

● ●

●●

● ●●

● ●

● ●

●●

●●

●●

●●

●●

●●

●●

●●●

●●

● ●

●●

●●●

●●

●●

●●

●●

●●

● ●

●●

● ●

●●

●●

●●

●●

●●

●● ●

●●●● ●

●●

● ●

●●

●●

●●

●●

●●

● ●

●●

● ●

●●

●●

●●

●● ●

● ●

● ●

●● ●●

●●

●●●

●●

●●●

●●

● ●

●●

●●

●●

●●

●●

●●

●●

●●

●●●

●●

●●

●●

●●●

● ●● ●

●●

●●

●●

●●

●●

● ●

●●

●●

●●

●●

●●

● ●

● ●

●●

●●●

●●

●●

●●

● ●●

● ●

● ●●●

●●

●●

●●

●●

●●

●●●

●●

● ●

●●

● ●

●●

●●

●●

●●

● ●

●●●

●●

●●

●●

●●

●● ●

●●

●●

● ●●●

●●

● ●

●●

●●

● ●

● ●●

●●

●●

●●

●●

●●

●●●

●● ●● ●

● ●●

●●

●● ●● ●●

● ●

●●

● ●

●●

●●

●●

●●

●●

● ●

● ●

●●●

●● ●

●●

● ●

●●

● ●

● ●●

●●

●●

●●

●●

●● ●

●●

●●

● ●

●●

●●

● ●

●●

●● ●

●●

● ● ●

●●

●●

●●

● ●

●●

●●

● ●

●●

●●

●●

●●

● ●●

●●

● ●

● ●●

●●

●●

● ●

●●

●●

●●

● ●●

●●

● ●

● ●

●●

●●

●●●

●●

●● ●

●●●

●●

● ●

●●

●●

●●

●●

●●

●●

●●

● ●

● ●

●●

● ●

●●●

●●

●●

●●

●●

●●

●●

●●

●●

●●

●●

●●

●●

●●

●●

●●

●●

●●

● ●

●●● ●

● ●

● ●

●●

●●

●●

●●

●●●

●●●

● ●●●● ●●

●●

●●

●●

●●● ● ●

● ●

●●●

●●

● ●

●● ●

●●

●●

●●●

●●

●●●

●●

●●

●●

●●

●●

● ●

●●

●●

●●

●●

●●

● ●

●●●

●●

●●

●●

●●●

●●

●●

●●

● ● ●

●●

●●

● ●

●● ●

● ●

● ●

●●

● ●

●●

●●

● ●●

●●

●●

●●

●●

●●

● ●

● ●

●●●

●●●●●

●●

●●

●●

●●

● ●

● ●

●●

●●

●●

● ●

● ●

●● ●●

●●

●●

● ●

● ●

●●

●●

● ●

●●●●

●●●

●●

●●

●●

● ●

●●

●●

●●

●●

●●

●●

●●

● ●

●●

●●

●●

● ●

●●

●●

●●

●●

● ●●

●●

●●

●●

● ●

● ●

●●

● ●

● ●

●●●

●●

●●

●●

●●

●●

●●

●●

●●

●●

●●

●●

●●

●●

●●

● ●

● ●

●●

●●●

●●

●●●

●●

● ●

●●

● ●

●●

●●

●●

●●

●●

●●

●●

● ●

●●

●●

●●

●●

●●

●●

●●

●●

●●

●●

●●

●●

● ●

●●

●●

●●

●●

●●

●●

●●

●●

● ●

●●

●●

●●

● ●

●●

●●

●●

●●

● ●●●●

●●●

●●

●● ●

● ●

● ● ●

●●

●●

●● ●

●●

●●

●●

●●

●●

●●

●●

●●

●●

●●

●●

●●

●●

●●

●●

●●

●●

●●

●●

●●

●●

●●

● ●

●●●

●●

● ●●

●●

● ●

●●

●●

●●

● ●

●●

● ●

●●

●●

●●

●●

●●

●●

●●

●●

● ●

●●

●●

● ●●

●●

●●●

●●

●●

●●

● ●

● ●

●●

●●

●●

●●

●●●●

●●●

● ●●

● ●

●●

●● ●●

●●

● ●●

●● ●

●●●

●●

●●●

●●●

● ●

● ●

●●

● ●

●●

●●

●●

● ●

●●

●●

●●

● ●

●●

●●

●●

● ●

●●

●●

●●

● ●

● ●●

●●

● ●●

●●

●●

●●

●●

●●

●●

●●●

●●

●●

●●

●●

● ●

●●

●●

●●

●●●

● ●

●●

● ●

●●

●● ●

●●

●●

●●

●●

●●

●●

● ●

● ●

●●

●●

●●

●●

●●

●●

●●

●● ●

●●

●●

●●

●●● ●

●●

●●

●●

● ●

● ●●

●●

●●

●●

●●

●●

●●

●●

●●

●●

●●

● ●

●●

●●●

●●

●●

●●

●●

●●●

●●

●●

●●

●●

●●

●●

● ●

●●

●●

●●

●●

●●

●● ●

●●●●●

●●

●●

●●

●●●

●●

●●●

● ●

●●

●●

● ●

●●

●●

●●

●●

●●

●●

● ●

●●

● ●

●●

●●

● ●●

●●

● ●●

●●

●●

●●

● ●

●●

● ●

● ●

●●

●●

●●

●●

● ●

●●

●●

●●

●●

●●

●●

●●

●●

●●

●●

●●

●●

●●

●●

●●

●●

●●

●●

● ●

●●

●●

●●

● ●

●●●

● ●

●●

●●

●●

●●

●●

●●

● ●

●●

●● ●

●●

●●

●●

● ●

●●

● ●

●●

●●

●●

● ●●

●●

● ●

● ●

●●

●●

●●

●●

●●

● ●

●● ●

●●

● ●

●●

●●

● ●●

●●

●●

● ●

●●

●●

●●

●●

●●

●●

●●

● ●

●●

●●

●●

●●●

●●

●●

●●

● ●

● ●

●●

● ●

● ●

● ●

●● ● ●

●●

●●●

●●

● ●●

●●

●●

●●

● ●●●

●●

● ●●

● ●

●●

● ●

● ●

●●

●●

●●

●●

● ●

●●

●●

● ●

●●

●●

●●

●●

●●

●●

●●●

●●

●●

●●●

●●

●● ● ●

● ●●

● ●

●●

●●

●●

● ●

● ●

● ●●

●●

●●

●●

●●

●●

●●

● ●

●●●

●●

●● ●

● ●

●●

●●

●●

●●

● ●

●●

● ●

●●

●●

●●

●●●

●●

●●

●●

●●

●●

●●

●●

● ●

●●

●●

●●

●●

●●

● ●

●●●

●●

●●

●●

●●●

●●

●●

●●●

●● ●

●●

●●

●●

●●

●●

●●

● ●● ●

●●

●●

●●

● ●●

●●

● ●

●●

●●

●●

● ●

●●

●●●

●●

●●●

● ●

●●

●●

●●

●●

●●

●●

●●

●●

●● ●

●●

●●

●●●● ●●

●●

● ●

● ●● ● ●●

● ●

●●

●●

●●

●●●●

●●

●●

●● ●

● ●●

●●

●●

●●

●●●●

●●

●●

●●

●●

●●

●●

●●

● ●

●●

●●

●●

●●●

● ●

●●

●●

●● ●●

● ●

●● ●

●●●

● ●

● ●

●●

●●

●●

●● ●

● ● ●

●●

● ●

●●

●●

●●

● ● ●●

●●

●●●

●●

● ●

●●

●●

● ● ●

●●

●●

●●

●●

●●●

●●

●●

●●

● ●●

●●

●● ●

●●

●●

●●

●●

● ●● ●

●●

●●

●●

●●

● ●●

●●

●●

●●

●●

●●

● ●

●●●

●●

● ●● ● ●

●●

●●

●●

● ●

●●

●●

●●

●●

●●

● ●

●●

●●

●●

●●

● ●

●●●

●●●●

●● ●

●● ●

●●

●●

●●

●● ●

●●

●●

●●

● ●

●●

●●● ●

●●

●●

●●

●●

●●

●●

●●

●●

●●

●●●

●●●

●●

●●●

●●

● ●

●●

●●

●●

● ●

●●

●● ●

●●

● ●●

●●

● ●

●●

●●

●●

● ●

●●

● ●

●●

●●●

●●

●●

● ●

●●

● ●

●●

●●

●●

●●

●●

●●

● ●

●●

●●

●●

●●

●●●

●●

●●

●●

●● ●

● ●

●●

●●

●●●

●●

●●●

●●

● ●

● ●

● ●

●●

●●

●●

●●

●●

●●

●●

●●

●●

● ●

●●

● ●

●●

●●

●●

●● ●

●●

●●

● ● ●

●●

-20 -15 -10

-50

5

A = log2( Liver NL Kidney NK)

M=

log 2

(Liv

erN

L)-

log 2

(Kid

ney

NK)

●●

●●

●●

●●

●●

●●

●●

● ●

●●

●●

●●●

●●

●●

●●

●●

●●

●●●

●● ●

●●

●●

● ●

●●●

●●

●●

●●

●●

● ●

●●

●●

●●

● ●

●●

●●

●●●

●●

● ●●

● ●

●●

● ●

●●

●●

●●

●●

●●

●●

●●

●●

●●

●●

●●

●●

●●

●●

●●

●●

●●

● ●●

●●

●●

●●

●●

● ●

●●

●●

●●

●●

●●

●●

●●

●●

●●

● ●

●●

●●

●●

Housekeeping genesUnique to a sample

(c)

Page 39: RNA-seq analysis - Bioinformaticsbioinformatics.org.au/ws/wp-content/uploads/sites/... · Collaborave analysis and methods development Transcriptomics Epigenomics Genomics Clinical

Sta6s6caltes6ngforDE

•  ForEACHGENE,isthemeanexpressionlevelforthegeneunderonecondi6onsignificantlydifferentfromthemeanexpressionlevelunderadifferentcondi6on?

39

TagID A1 A2 A3 B1 B2 B2ENSG00000124208 478 619 559 4830 7165 6651

ENSG00000182463 27 20 18 48 55 56

ENSG00000125835 132 290 450 560 408 266ENSG00000125834 320 462 355 131 99 91ENSG00000197818 21 29 23 52 44 65

… …tensofthousandsmoretags…

Page 40: RNA-seq analysis - Bioinformaticsbioinformatics.org.au/ws/wp-content/uploads/sites/... · Collaborave analysis and methods development Transcriptomics Epigenomics Genomics Clinical

Samplingreadsfrompopula6onofDNAfragmentis(approx.)mul2nomial

•  Take sample •  Sequence DNA

Library 1

Feature 1 λ1 Feature 2 λ2 Feature 3 λ3 Feature 4 λ4 Feature 5 λ5 Feature 6 λ6 …

DNA population

Page 41: RNA-seq analysis - Bioinformaticsbioinformatics.org.au/ws/wp-content/uploads/sites/... · Collaborave analysis and methods development Transcriptomics Epigenomics Genomics Clinical

For a single gene, it’s a coin toss, i.e. Binomial

Library 1

… feature i λi …

Yi ~ Binomial( M, λi ) Yi - observed number of reads for feature i M - total number of sequences λi - proportion Large M, small λi à approximated well by Poisson( μi = M�λi )

Page 42: RNA-seq analysis - Bioinformaticsbioinformatics.org.au/ws/wp-content/uploads/sites/... · Collaborave analysis and methods development Transcriptomics Epigenomics Genomics Clinical

42

ASmallRNA-SeqExperiment(TechReps)

Condi6onA Condi6onB

λg1 λg2 λg3 λg4

yg1 yg2 yg3 yg4

Genesg=1,…,30k

M1

M2M3 M4

E(ygi)=MiλgiReadsMi≈20million

Page 43: RNA-seq analysis - Bioinformaticsbioinformatics.org.au/ws/wp-content/uploads/sites/... · Collaborave analysis and methods development Transcriptomics Epigenomics Genomics Clinical

TrueTechnicalRepsShowPoissonVaria6onforEachGene

Data:Marionietal.,GenomeRes,2008 43

DavisMcCarthy

Page 44: RNA-seq analysis - Bioinformaticsbioinformatics.org.au/ws/wp-content/uploads/sites/... · Collaborave analysis and methods development Transcriptomics Epigenomics Genomics Clinical

44

ASmallRNA-SeqExperiment(BiologicalReps)

Condi6onA Condi6onB

λg1 λg2 λg3 λg4

yg1 yg2 yg3 yg4

Genesg=1,…,30k

M1

M2M3 M4

E(ygi)=MiλgiReadsMi≈20million

DavisMcCarthy

Page 45: RNA-seq analysis - Bioinformaticsbioinformatics.org.au/ws/wp-content/uploads/sites/... · Collaborave analysis and methods development Transcriptomics Epigenomics Genomics Clinical

BiologicalReplicateDatashowsQuadra6cMean-VarianceRela6onship

(developmentcycleofslimemould,2samplesathr00,&2athr04)

binnedvariance,samplevariance

Data:Parikhetal,GenomeBiology,2010

45DavisMcCarthy

Page 46: RNA-seq analysis - Bioinformaticsbioinformatics.org.au/ws/wp-content/uploads/sites/... · Collaborave analysis and methods development Transcriptomics Epigenomics Genomics Clinical

Manydifferentsta6s6calmethods•  Modelthecountsdirectly

– Nega6vebinomialmodellingisbestbecauseitcapturesbiologicalaswellastechnicalvariability

– MostpopularpackagesinR•  edgeR•  DESeq/DESeq2•  Lotsofothersexist(baySeq,NBPSeq,…)

•  Transformthecountsandusednormalbasedmethods– Voom+limma

Page 47: RNA-seq analysis - Bioinformaticsbioinformatics.org.au/ws/wp-content/uploads/sites/... · Collaborave analysis and methods development Transcriptomics Epigenomics Genomics Clinical

Sta6s6caltes6nggiveseachgeneap-valueforevidenceofDE

TagID P-valueENSG00000124208 0.0002

ENSG00000182463 0.12

ENSG00000125835 0.34

ENSG00000125834 0.08

ENSG00000197818 0.64

ENSG00000125831 1

ENSG00000215443 1

ENSG00000222008 0.06

ENSG00000101444 0.73

ENSG00000101333 0.22

… …tensofthousandsmoretags…

TagID A1 A2 A3 B1 B2 B2ENSG00000124208 478 619 559 4830 7165 6651ENSG00000182463 27 20 18 48 55 36ENSG00000125835 132 290 450 560 408 266ENSG00000125834 320 462 355 131 99 91ENSG00000197818 21 29 23 52 44 65ENSG00000125831 0 0 0 0 0 0ENSG00000215443 4 4 4 9 7 3ENSG00000222008 30 23 23 0 0 0ENSG00000101444 46 63 55 54 53 52ENSG00000101333 2256 2793 2931 2702 2976 2226

… …tensofthousandsmoretags…

Page 48: RNA-seq analysis - Bioinformaticsbioinformatics.org.au/ws/wp-content/uploads/sites/... · Collaborave analysis and methods development Transcriptomics Epigenomics Genomics Clinical

RNA-seqanalysisstepsRawsequencereads

Mapontogenome

Summarizereadstotranscripts

Sta6s6caltes6ng:Determinedifferen6allyexpressedgenes

Systemsbiology

DenovoassemblyAnnota6onbased Genomeguidedassembly

Whichtranscriptome?

Page 49: RNA-seq analysis - Bioinformaticsbioinformatics.org.au/ws/wp-content/uploads/sites/... · Collaborave analysis and methods development Transcriptomics Epigenomics Genomics Clinical

RNA-seqanalysisstepsRawsequencereads

Mapontogenome

Summarizereadstotranscripts

Sta6s6caltes6ng:Determinedifferen6allyexpressedgenes

Systemsbiology

DenovoassemblyAnnota6onbased Genomeguidedassembly

Whichtranscriptome?

Learnsomething!

Page 50: RNA-seq analysis - Bioinformaticsbioinformatics.org.au/ws/wp-content/uploads/sites/... · Collaborave analysis and methods development Transcriptomics Epigenomics Genomics Clinical

MovingbeyondDifferen6alExpression

Page 51: RNA-seq analysis - Bioinformaticsbioinformatics.org.au/ws/wp-content/uploads/sites/... · Collaborave analysis and methods development Transcriptomics Epigenomics Genomics Clinical

Findingfusiongenesincancer

•  Genomicsbreaksandrearrangementscanleadtogenefusions•  Somefusionsareoncogenic,otherarejustbystanders.•  Iden6fyingoncogenicgenefusionsisbeneficialfor

•  ClinicalTreatmentse.g.•  BCR-ABLfusionin95%ofCMLsImaAnib

Page 52: RNA-seq analysis - Bioinformaticsbioinformatics.org.au/ws/wp-content/uploads/sites/... · Collaborave analysis and methods development Transcriptomics Epigenomics Genomics Clinical

•  Transcriptomesofanyorganismscanbesequencedandanalysed

Non-modelorganisms

Blackwidowvenomtranscriptome

Desertpoplartranscriptomeinsalinecondi6ons

Page 53: RNA-seq analysis - Bioinformaticsbioinformatics.org.au/ws/wp-content/uploads/sites/... · Collaborave analysis and methods development Transcriptomics Epigenomics Genomics Clinical

Exploringthehumantranscriptome

Mostgeneshavemorethanoneexpressedisoform Mostgenehaveonemajorisoform

Page 54: RNA-seq analysis - Bioinformaticsbioinformatics.org.au/ws/wp-content/uploads/sites/... · Collaborave analysis and methods development Transcriptomics Epigenomics Genomics Clinical

Unknownandrareeventsinthehumantranscriptome

•  ENCODEsays–75%ofthegenomeistranscribed

Page 55: RNA-seq analysis - Bioinformaticsbioinformatics.org.au/ws/wp-content/uploads/sites/... · Collaborave analysis and methods development Transcriptomics Epigenomics Genomics Clinical

Non-canonicalRNAstructuresCircularRNAs

Intronreten6on

Memczaketal.Nature,2013

Wongetal.Cell,2013

Page 56: RNA-seq analysis - Bioinformaticsbioinformatics.org.au/ws/wp-content/uploads/sites/... · Collaborave analysis and methods development Transcriptomics Epigenomics Genomics Clinical

Thefuture

•  Analysismethodologyiscri6calands6lldevelopingforspecificpurposes

•  Effec6velydealingwithnogenomeorpoorqualitygenomesorcancer

•  Integra6ngRNA-seqdatawithothergenomicsdata

•  Opportuni6estousethisdatainnewandimagina6veways–requiresnewanalysismethodology