Towards the Arabidopsis Haplotype Map using Arrays Justin Borevitz Salk Institute naturalvariation.org
Talk Outline Single Feature Polymorphisms (SFPs) –Potential deletions Bulk Segregant Mapping –Extreme Array Mapping Haplotype analysis Expression Analysis New Arrays
What is Array Genotyping? Affymetrix expression GeneChips contain 202,806 unique 25bp oligo nucleotides. 11 features per probset for genes New array’s have even more Genomic DNA is randomly labeled with biotin, product ~50bp. 3 independent biological replicates compared to the reference strain Col GeneChip
Potential Deletions
Spatial Correction Spatial Artifacts Improved reproducibility Next: Quantile Normalization
False Discovery and Sensitivity PM only SAM threshold 5% FDR GeneChip SFPs nonSFPs Cereon marker accuracy % Sequence Sensitivity Polymorphic % Non-polymorphic False Discovery rate: 3% Test for independence of all factors: Chisq = , df = 1, p-value = 1.845e-40 SAM threshold 18% FDR GeneChip SFPs nonSFPs Cereon marker accuracy % Sequence Sensitivity Polymorphic % Non-polymorphic False Discovery rate: 13% Test for independence of all factors: Chisq = , df = 1, p-value = 1.309e-59 3/4 Cvi markers were also confirmed in PHYB 90%80%70% 41%53%85% 90%80%70% 67%85%100% Cereon may be a sequencing Error TIGR match is a match
Chip genotyping of a Recombinant Inbred Line 29kb interval Discovery 6 replicates X $500 12,000 SFPs = $0.25 Typing 1 replicate X $500 12,000 SFPs = $0.041
Potential Deletions >500 potential deletions 45 confirmed by Ler sequence 23 (of 114) transposons Disease Resistance (R) gene clusters Single R gene deletions Genes involved in Secondary metabolism Unknown genes
Potential Deletions Suggest Candidate Genes FLOWERING1 QTL Chr1 (bp) Flowering Time QTL caused by a natural deletion in MAF1 MAF1 MAF1 natural deletion
Fast Neutron deletions FKF1 80kb deletion CHR1cry2 10kb deletion CHR1 Het
Map bibb 100 bibb mutant plants 100 wt mutant plants
bibb mapping ChipMap AS1 Bulk segregant Mapping using Chip hybridization bibb maps to Chromosome2 near ASYMETRIC LEAVES1
BIBB = ASYMETRIC LEAVES1 Sequenced AS1 coding region from bib-1 …found g -> a change that would introduce a stop codon in the MYB domain bibbas1-101 MYB bib-1 W49* as-101 Q107* as1 bibb AS1 (ASYMMETRIC LEAVES1) = MYB closely related to PHANTASTICA located at 64cM
stamenstay Ler Sarah Liljegren Mapping confirmed
ein6een double mutant Ramlah Nehring Mapping confirmed
Array Haplotyping What about Diversity/selection across the genome? A genome wide estimate of population genetics parameters, θ w, π, Tajima’D, ρ LD decay, Haplotype block size Deep population structure? Col, Lz, Ler, Bay, Shah, Cvi, Kas, C24, Est, Kin, Mt, Nd, Sorbo, Van, Ws2
Pairwise Correlation between and within replicates
Array Haplotyping Inbred lines Low effective recombination due to partial selfing Extensive LD blocks ColLerCviKasBayShahLzNd Chromosome1 ~500kb
Distribution of T-stats null (permutation) actual Not ColColNANA duplications 32,427 Calls 208,729 12,250 SFPs
Sequence confirmation of SFPs
SFPs for reverse genetics 14 Accessions 30,950 SFPs`
Chromosome Wide Diversity
Diversity 50kb windows
Tajima’s D like 50kb windows
differences may be due to expression or hybridization
PAG1 down regulated in Cvi PLALE GREEN1 knock out has long hypocotyl in red light
RNADNA Universal Whole Genome Array Transcriptome Atlas Expression levels Tissues specificity Transcriptome Atlas Expression levels Tissues specificity Gene Discovery Gene model correction Non-coding/ micro-RNA Antisense transcription Gene Discovery Gene model correction Non-coding/ micro-RNA Antisense transcription Alternative Splicing Comparative Genome Hybridization (CGH) Insertion/Deletions Comparative Genome Hybridization (CGH) Insertion/Deletions Methylation Chromatin Immunoprecipitation ChIP chip Chromatin Immunoprecipitation ChIP chip Polymorphism SFPs Discovery/Genotyping Polymorphism SFPs Discovery/Genotyping ~35 bp tile,non-repetitive regions, “good” binding oligos,evenly spaced
ChipViewer: Mapping of transcriptional units of ORFeome From 2000v At1g09750 (MIPS) to the latest AGI At1g v Annotation (MIPS) The latest AGI Annotation
SNP SFP MMMMMM MMMMMM Chromosome (bp) conservation SNP ORFa start AAAAA Transcriptome Atlas ORFb deletion Improved Genome Annotation
Review Single Feature Polymorphisms (SFPs) can be used to Potential deletions (candidate genes) Identify recombination breakpoints eXtreme Array Mapping Haplotyping Diversity/Selection Association Mapping
NaturalVariation.org Syngenta Hur-Song Chang Tong Zhu UC Davis Julin Maloof University of Guelph, Canada Dave Wolyn Sainsbury Laboratory Jonathan Jones NaturalVariation.org Salk Jon Werner Todd Mockler Sarah Liljegren Ramlah Nehring Huaming Chen Joanne Chory Detlef Weigel Joseph Ecker UC San Diego Charles Berry Scripps Sam Hazen Elizabeth Winzeler Salk Jon Werner Todd Mockler Sarah Liljegren Ramlah Nehring Huaming Chen Joanne Chory Detlef Weigel Joseph Ecker UC San Diego Charles Berry Scripps Sam Hazen Elizabeth Winzeler Syngenta Hur-Song Chang Tong Zhu UC Davis Julin Maloof University of Guelph, Canada Dave Wolyn Sainsbury Laboratory Jonathan Jones