Objectives

After completing this module, the student will:

  1. Learn about the bioconductor project and it’s goals
  2. Learn how to install bioconductor packages
  3. Learn how to get help with bioconductor
  4. Perform some analysis with bioconductor, to learn the basic principles of bioconductor packages

Introduction

Bioconductor is an open source project for the analysis of biomedical data. It contains more than 1000 packages for example data, analysis tools, and development tools for building new packages. The bioconductor website http://bioconductor.org/ contains much more information on the project.

From the bioconductor webpage

The broad goals of the Bioconductor project are:

  • To provide widespread access to a broad range of powerful statistical and graphical methods for the analysis of genomic data.
  • To facilitate the inclusion of biological metadata in the analysis of genomic data, e.g. literature data from PubMed, annotation data from Entrez genes.
  • To provide a common software platform that enables the rapid development and deployment of extensible, scalable, and interoperable software.
  • To further scientific understanding by producing high-quality documentation and reproducible research.
  • To train researchers on computational and statistical methods for the analysis of genomic data.

We will view some exaples inspired by the paper:

http://www.ncbi.nlm.nih.gov/pmc/articles/PMC4509590/

Installing

Bioconductor has special tools for installing new packages.

source("http://bioconductor.org/biocLite.R")

Once you have loaded the installer, you can use it to install bioconductor packages.

biocLite("GenomicRanges")

A package must be loaded into each session that makes use of the package.

library(GenomicRanges)
## Loading required package: BiocGenerics
## Loading required package: parallel
## 
## Attaching package: 'BiocGenerics'
## The following objects are masked from 'package:parallel':
## 
##     clusterApply, clusterApplyLB, clusterCall, clusterEvalQ,
##     clusterExport, clusterMap, parApply, parCapply, parLapply,
##     parLapplyLB, parRapply, parSapply, parSapplyLB
## The following objects are masked from 'package:stats':
## 
##     IQR, mad, xtabs
## The following objects are masked from 'package:base':
## 
##     anyDuplicated, append, as.data.frame, as.vector, cbind,
##     colnames, do.call, duplicated, eval, evalq, Filter, Find, get,
##     grep, grepl, intersect, is.unsorted, lapply, lengths, Map,
##     mapply, match, mget, order, paste, pmax, pmax.int, pmin,
##     pmin.int, Position, rank, rbind, Reduce, rownames, sapply,
##     setdiff, sort, table, tapply, union, unique, unlist, unsplit
## Loading required package: S4Vectors
## Loading required package: stats4
## Loading required package: IRanges
## Loading required package: GenomeInfoDb

Documentation

bioconductor contains extensive documentation, usually of a very high quality.

help(package="GenomicRanges")

The package vignettes, in particular, have high level overviews of the package, with examples and data.

vignette("GenomicRangesIntroduction")

Data

As a general principle, bioconductor tries to maintain metadata about your experiment together with the raw data whenever possible. It is very rare to see a plain matrix of data.

In the paper, the SummarizedExperiment data structure is mentioned. We will use the vignette to explore a summarized experiment.

biocLite("airway")
library(airway)
## Loading required package: SummarizedExperiment
## Loading required package: Biobase
## Welcome to Bioconductor
## 
##     Vignettes contain introductory material; view with
##     'browseVignettes()'. To cite Bioconductor, see
##     'citation("Biobase")', and for packages 'citation("pkgname")'.
data(airway, package="airway")
airway
## class: RangedSummarizedExperiment 
## dim: 64102 8 
## metadata(1): ''
## assays(1): counts
## rownames(64102): ENSG00000000003 ENSG00000000005 ... LRG_98 LRG_99
## rowRanges metadata column names(0):
## colnames(8): SRR1039508 SRR1039509 ... SRR1039520 SRR1039521
## colData names(9): SampleName cell ... Sample BioSample

Here we extract one assay from the airway object.

head(assays(airway)$counts)
##                 SRR1039508 SRR1039509 SRR1039512 SRR1039513 SRR1039516
## ENSG00000000003        679        448        873        408       1138
## ENSG00000000005          0          0          0          0          0
## ENSG00000000419        467        515        621        365        587
## ENSG00000000457        260        211        263        164        245
## ENSG00000000460         60         55         40         35         78
## ENSG00000000938          0          0          2          0          1
##                 SRR1039517 SRR1039520 SRR1039521
## ENSG00000000003       1047        770        572
## ENSG00000000005          0          0          0
## ENSG00000000419        799        417        508
## ENSG00000000457        331        233        229
## ENSG00000000460         63         76         60
## ENSG00000000938          0          0          0

Extensive data about each feature is directly available in the dataset.

head(rowRanges(airway))
## GRangesList object of length 6:
## $ENSG00000000003 
## GRanges object with 17 ranges and 2 metadata columns:
##        seqnames               ranges strand   |   exon_id       exon_name
##           <Rle>            <IRanges>  <Rle>   | <integer>     <character>
##    [1]        X [99883667, 99884983]      -   |    667145 ENSE00001459322
##    [2]        X [99885756, 99885863]      -   |    667146 ENSE00000868868
##    [3]        X [99887482, 99887565]      -   |    667147 ENSE00000401072
##    [4]        X [99887538, 99887565]      -   |    667148 ENSE00001849132
##    [5]        X [99888402, 99888536]      -   |    667149 ENSE00003554016
##    ...      ...                  ...    ... ...       ...             ...
##   [13]        X [99890555, 99890743]      -   |    667156 ENSE00003512331
##   [14]        X [99891188, 99891686]      -   |    667158 ENSE00001886883
##   [15]        X [99891605, 99891803]      -   |    667159 ENSE00001855382
##   [16]        X [99891790, 99892101]      -   |    667160 ENSE00001863395
##   [17]        X [99894942, 99894988]      -   |    667161 ENSE00001828996
## 
## ...
## <5 more elements>
## -------
## seqinfo: 722 sequences (1 circular) from an unspecified genome

As is information about each sample.

head(colData(airway))
## DataFrame with 6 rows and 9 columns
##            SampleName     cell      dex    albut        Run avgLength
##              <factor> <factor> <factor> <factor>   <factor> <integer>
## SRR1039508 GSM1275862   N61311    untrt    untrt SRR1039508       126
## SRR1039509 GSM1275863   N61311      trt    untrt SRR1039509       126
## SRR1039512 GSM1275866  N052611    untrt    untrt SRR1039512       126
## SRR1039513 GSM1275867  N052611      trt    untrt SRR1039513        87
## SRR1039516 GSM1275870  N080611    untrt    untrt SRR1039516       120
## SRR1039517 GSM1275871  N080611      trt    untrt SRR1039517       126
##            Experiment    Sample    BioSample
##              <factor>  <factor>     <factor>
## SRR1039508  SRX384345 SRS508568 SAMN02422669
## SRR1039509  SRX384346 SRS508567 SAMN02422675
## SRR1039512  SRX384349 SRS508571 SAMN02422678
## SRR1039513  SRX384350 SRS508572 SAMN02422670
## SRR1039516  SRX384353 SRS508575 SAMN02422682
## SRR1039517  SRX384354 SRS508576 SAMN02422673

Querying online databases

Since we have information on the features, we can query online databases to get more information.

head(rownames(airway))
## [1] "ENSG00000000003" "ENSG00000000005" "ENSG00000000419" "ENSG00000000457"
## [5] "ENSG00000000460" "ENSG00000000938"
rownames(airway)[5]
## [1] "ENSG00000000460"

These identifiers are Ensembl gene IDs. The biomaRt package can get the data related to the gene. Ensembl is a huge online database for dozens of organisms.

library(biomaRt)
mart = useEnsembl('ENSEMBL_MART_ENSEMBL')
dim(listDatasets(mart))
## [1] 69  3
head(listDatasets(mart))
##                          dataset
## 1         oanatinus_gene_ensembl
## 2        cporcellus_gene_ensembl
## 3        gaculeatus_gene_ensembl
## 4 itridecemlineatus_gene_ensembl
## 5         lafricana_gene_ensembl
## 6        choffmanni_gene_ensembl
##                                  description version
## 1     Ornithorhynchus anatinus genes (OANA5)   OANA5
## 2            Cavia porcellus genes (cavPor3) cavPor3
## 3     Gasterosteus aculeatus genes (BROADS1) BROADS1
## 4 Ictidomys tridecemlineatus genes (spetri2) spetri2
## 5         Loxodonta africana genes (loxAfr3) loxAfr3
## 6        Choloepus hoffmanni genes (choHof1) choHof1
mart=useEnsembl(biomart="ensembl", dataset="hsapiens_gene_ensembl")
head(listAttributes(mart))
##                    name           description
## 1       ensembl_gene_id       Ensembl Gene ID
## 2 ensembl_transcript_id Ensembl Transcript ID
## 3    ensembl_peptide_id    Ensembl Protein ID
## 4       ensembl_exon_id       Ensembl Exon ID
## 5           description           Description
## 6       chromosome_name       Chromosome Name
dim(listAttributes(mart))
## [1] 1319    2
g=getBM(attributes=c("ensembl_gene_id", "ensembl_transcript_id", "coding"),
        filters="ensembl_gene_id", 
        values=rownames(airway)[5],  
        mart=mart)
g
##                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                      ensembl_gene_id
## 1                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                               Sequence unavailable
## 2 ATGTTTTTACCTCATATGAACCACCTGACATTGGAACAGACTTTCTTTTCACAAGTGTTACCAAAGACTGTGAAATTATTCGATGACATGATGTATGAATTAACCAGTCAAGCCAGAGGACTGTCAAGCCAAAATTTGGAAATCCAGACCACTCTAAGGAATATTTTACAAACAATGGTGCAGCTCTTAGGAGCTCTCACAGGATGTGTTCAGCATATCTGTGCCACACAGGAATCCATCATTTTGGAAAATATTCAGAGTCTCCCCTCCTCAGTCCTTCATATAATTAAAAGCACATTTGTGCATTGTAAGAATAGTGAATCTGTGTATTCTGGGTGTTTACACCTAGTTTCAGACCTTCTCCAGGCTCTTTTCAAGGAGGCCTATTCTCTTCAAAAGCAGTTAATGGAACTGCTGGACATGGTTTGCATGGACCCTTTAGTAGATGACAATGATGATATTTTGAATATGGTAATAGTTATTCATTCTTTATTGGATATCTGCTCTGTTATTTCCAGTATGGACCATGCATTTCATGCCAATACTTGGAAGTTTATAATTAAGCAGAGCCTTAAGCACCAGTCCATAATAAAAAGCCAGTTGAAACACAAAGATATAATTACTAGCTTGTGTGAAGACATTCTTTTCTCCTTCCATTCTTGTTTACAGTTAGCTGAGCAGATGACACAGTCAGATGCACAGGATAATGCTGACTACAGATTATTTCAGAAAACACTCAAATTGTGTCGTTTTTTTGCCAACTCCCTTTTGCACTACGCTAAGGAATTTCTTCCTTTCCTCTCTGATTCTTGCTGTACTTTGCACCAACTGTATCTTCAGATACACAGCAAGTTTCCTCCAAGCCTTTATGCTACCAGGATTTCTAAAGCACACCAAGAGGAAATAGCAGGTGCTTTCCTAGTGACACTGGATCCACTTATCAGTCAGCTGCTCACATTTCAGCCTTTCATGCAGGTGGTTTTGGACAGTAAATTAGACCTGCCATGTGAACTGCAGTTTCCACAATGTCTTCTTCTGGTTGTTGTCATGGATAAGCTGCCATCTCAGCCTAAGGAAGTGCAAACCCTGTGGTGCACAGACAGCCAGGTCTCAGAAACGACAACCAGGATATCTCTACTCAAAGCCGTTTTCTACAGTTTTGAGCAGTGTTCTGGTGAACTCTCTCTACCTGTTCATTTACAGGGATTAAAGAGTAAGGGGAAAGCTGAGGTGGCTGTCACCTTGTATCAGCATGTTTGTGTTCATCTGTGTACATTTATTACTTCCTTTCATCCCTCACTGTTTGCTGAACTGGATGCTGCTCTGCTGAATGCTGTACTTAGTGCTAATATGATCACCTCTTTGTTAGCTATGGATGCATGGTGCTTCCTTGCTCGATATGGGACTGCTGAACTGTGTGCACACCATGTCACCATAGTGGCTCATCTGATAAAGTCATGCCCTGGAGAATGTTATCAACTCATCAACCTATCAATACTGTTGAAGCGTCTCTTTTTCTTCATGGCACCACCCCATCAGCTGGAGTTTATCCAGAAATTTTCCCCAAAAGAAGCAGAAAATCTGCCTCTGTGGCAACATATTTCCTTCCAGGCGTTACCTCCTGAGCTTAGGGAACAAACTGTCCATGAGGTCACCACAGTAGGCACTGCAGAATGCAGGAAATGGCTGAGCAGGAGTCGTACTTTGGGAGAACTAGAATCTCTGAACACAGTACTGTCTGCTTTGCTTGCAGTATGTAATTCTGCTGGTGAAGCTTTGGATACAGGAAAACAAACTGCAATTATCGAAGTTGTGAGTCAGCTTTGGGCTTTTTTAAACATTAAACAGGTAGCAGATCAACCTTATGTTCAACAGACATTCAGCCTTTTACTTCCACTGTTGGGATTTTTCATTCAAACTCTAGATCCTAAACTGATACTTCAGGCAGTAACTTTGCAGACCTCGCTACTTAAATTAGAGCTTCCTGACTATGTTCGTTTGGCAATGTTGGATTTTGTATCTTCTTTAGGAAAACTTTTTATACCTGAAGCTATCCAGGACAGAATTCTGCCCAACCTGTCCTGTATGTTTGCCTTACTGCTAGCTGACAGGAGTTGGCTGCTAGAACAACATACCTTGGAGGCGTTTACTCAGTTCGCTGAGGGAACAAATCATGAAGAGATAGTTCCACAGTGTCTCAGTTCTGAAGAAACTAAGAACAAAGTTGTATCCTTTCTGGAGAAGACTGGGTTTGTAGATGAAACTGAAGCTGCCAAAGTGGAACGTGTGAAACAGGAAAAAGGTATTTTCTGGGAACCCTTTGCTAATGTGACTGTAGAAGAAGCAAAGAGGTCATCTTTACAGCCTTATGCAAAAAGAGCTCGTCAGGAGTTCCCCTGGGAAGAAGAGTACAGGTCAGCGCTGCATACAATAGCAGGGGCTTTGGAAGCAACTGAGTCACTACTCCAAAAGGGTCCTGCTCCAGCCTGGCTTTCAATGGAAATGGAGGCGCTCCAAGAAAGGATGGATAAGCTAAAACGTTACATACATACTCTAGGGTGA
## 3                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                               Sequence unavailable
## 4                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                               Sequence unavailable
## 5                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                          ATGCAGGTGGTTTTGGACAGTAAATTAGACCTGCCATGTGAACTGCAGTTTCCACAATGTCTTCTTCTGGTTGTTGTCATGGATAAGCTGCCATCTCAGCCTAAGGAAGTGCAAACCCTGTGGTGCACAGACAGCCAGGTCTCAGAAACGACAACCAGGATATCTCTACTCAAAGCCGTTTTCTACAGTTTTGAGCAGTGTTCTGGTGAACTCTCTCTACCTGTTCATTTACAGGGATTAAAGAGTAAGGGGAAAGCTGAGGTGGCTGTCACCTTGTATCAGCATGTTTGTGTTCATCTGTGTACATTTATTACTTCCTTTCATCCCTCACTGTTTGCTGAACTGGATGCTGCTCTGCTGAATGCTGTACTTAGTGCTAATATGATCACCTCTTTGTTAGCTATGGATGCATGGTGCTTCCTTGCTCGATATGGGACTGCTGAACTGTGTGCACACCATGTCACCATAGTGGCTCATCTGATAAAGTCATGCCCTGGAGAATGTTATCAACTCATCAACCTATCAATACTGTTGAAGCGTCTCTTTTTCTTCATGGCACCACCCCATCAGCTGGAGTTTATCCAGAAATTTTCCCCAAAAGAAGCAGAAAATCTGCCTCTGTGGCAACATATTTCCTTCCAGGCGTTACCTCCTGAGCTTAGGGAACAAACTGTCCATGAGGTCACCACAGTAGGCACTGCAGAATGCAGGAAATGGCTGAGCAGGAGTCGTACTTTGGGAGAACTAGAATCTCTGAACACAGTACTGTCTGCTTTGCTTGCAGTATGTAATTCTGCTGGTGAAGCTTTGGATACAGGAAAACAAACTGCAATTATCGAAGTTGTGAGTCAGCTTTGGGCTTTTTTAAACATTAAACAGGTAGCAGATCAACCTTATGTTCAACAGACATTCAGCCTTTTACTTCCACTGTTGGGATTTTTCATTCAAACTCTAGATCCTAAACTGATACTTCAGGCAGTAACTTTGCAGACCTCGCTACTTAAATTAGAGCTTCCTGACTATGTTCGTTTGGCAATGTTGGATTTTGTATCTTCTTTAGGAAAACTTTTTATACCTGAAGCTATCCAGGACAGAATTCTGCCCAACCTGTCCTGTATGTTTGCCTTACTGCTAGCTGACAGGAGTTGGCTGCTAGAACAACATACCTTGGAGGCGTTTACTCAGTTCGCTGAGGGAACAAATCATGAAGAGATAGTTCCACAGTGTCTCAGTTCTGAAGAAACTAAGAACAAAGTTGTATCCTTTCTGGAGAAGACTGGGTTTGTAGATGAAACTGAAGCTGCCAAAGTGGAACGTGTGAAACAGGAAAAAGGTATTTTCTGGGAACCCTTTGCTAATGTGACTGTAGAAGAAGCAAAGAGGTCATCTTTACAGCCTTATGCAAAAAGAGCTCGTCAGGAGTTCCCCTGGGAAGAAGAGTACAGGTCAGCGCTGCATACAATAGCAGGGGCTTTGGAAGCAACTGAGTCACTACTCCAAAAGGGTCCTGCTCCAGCCTGGCTTTCAATGGAAATGGAGGCGCTCCAAGAAAGGATGGATAAGCTAAAACGTTACATACATACTCTAGGGTGA
## 6                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                               Sequence unavailable
## 7 ATGTTTTTACCTCATATGAACCACCTGACATTGGAACAGACTTTCTTTTCACAAGTGTTACCAAAGACTGTGAAATTATTCGATGACATGATGTATGAATTAACCAGTCAAGCCAGAGGACTGTCAAGCCAAAATTTGGAAATCCAGACCACTCTAAGGAATATTTTACAAACAATGGTGCAGCTCTTAGGAGCTCTCACAGGATGTGTTCAGCATATCTGTGCCACACAGGAATCCATCATTTTGGAAAATATTCAGAGTCTCCCCTCCTCAGTCCTTCATATAATTAAAAGCACATTTGTGCATTGTAAGAATAGTGAATCTGTGTATTCTGGGTGTTTACACCTAGTTTCAGACCTTCTCCAGGCTCTTTTCAAGGAGGCCTATTCTCTTCAAAAGCAGTTAATGGAACTGCTGGACATGGTTTGCATGGACCCTTTAGTAGATGACAATGATGATATTTTGAATATGGTAATAGTTATTCATTCTTTATTGGATATCTGCTCTGTTATTTCCAGTATGGACCATGCATTTCATGCCAATACTTGGAAGTTTATAATTAAGCAGAGCCTTAAGCACCAGTCCATAATAAAAAGCCAGTTGAAACACAAAGATATAATTACTAGCTTGTGTGAAGACATTCTTTTCTCCTTCCATTCTTGTTTACAGTTAGCTGAGCAGATGACACAGTCAGATGCACAGGATAATGCTGACTACAGATTATTTCAGAAAACACTCAAATTGTGTCGTTTTTTTGCCAACTCCCTTTTGCACTACGCTAAGGAATTTCTTCCTTTCCTCTCTGATTCTTGCTGTACTTTGCACCAACTGTATCTTCAGATACACAGCAAGTTTCCTCCAAGCCTTTATGCTACCAGGATTTCTAAAGCACACCAAGAGGAAATAGCAGGTGCTTTCCTAGTGACACTGGATCCACTTATCAGTCAGCTGCTCACATTTCAGCCTTTCATGCAGGTGGTTTTGGACAGTAAATTAGACCTGCCATGTGAACTGCAGTTTCCACAATGTCTTCTTCTGGTTGTTGTCATGGATAAGCTGCCATCTCAGCCTAAGGAAGTGCAAACCCTGTGGTGCACAGACAGCCAGGTCTCAGAAACGACAACCAGGATATCTCTACTCAAAGCCGTTTTCTACAGTTTTGAGCAGTGTTCTGGTGAACTCTCTCTACCTGTTCATTTACAGGGATTAAAGAGTAAGGGGAAAGCTGAGGTGGCTGTCACCTTGTATCAGCATGTTTGTGTTCATCTGTGTACATTTATTACTTCCTTTCATCCCTCACTGTTTGCTGAACTGGATGCTGCTCTGCTGAATGCTGTACTTAGTGCTAATATGATCACCTCTTTGTTAGCTATGGATGCATGGTGCTTCCTTGCTCGATATGGGACTGCTGAACTGTGTGCACACCATGTCACCATAGTGGCTCATCTGATAAAGTCATGCCCTGGAGAATGTTATCAACTCATCAACCTATCAATACTGTTGAAGCGTCTCTTTTTCTTCATGGCACCACCCCATCAGCTGGAGTTTATCCAGAAATTTTCCCCAAAAGAAGCAGAAAATCTGCCTCTGTGGCAACATATTTCCTTCCAGGCGTTACCTCCTGAGCTTAGGGAACAAACTGTCCATGAGGTCACCACAGTAGGCACTGCAGAATGCAGGAAATGGCTGAGCAGGAGTCGTACTTTGGGAGAACTAGAATCTCTGAACACAGTACTGTCTGCTTTGCTTGCAGTATGTAATTCTGCTGGTGAAGCTTTGGATACAGGAAAACAAACTGCAATTATCGAAGTTGTGAGTCAGCTTTGGGCTTTTTTAAACATTAAACAGGTAGCAGATCAACCTTATGTTCAACAGACATTCAGCCTTTTACTTCCACTGTTGGGATTTTTCATTCAAACTCTAGATCCTAAACTGATACTTCAGGCAGTAACTTTGCAGACCTCGCTACTTAAATTAGAGCTTCCTGACTATGTTCGTTTGGCAATGTTGGATTTTGTATCTTCTTTAGGAAAACTTTTTATACCTGAAGCTATCCAGGACAGAATTCTGCCCAACCTGTCCTGTATGTTTGCCTTACTGCTAGCTGACAGGAGTTGGCTGCTAGAACAACATACCTTGGAGGCGTTTACTCAGTTCGCTGAGGGAACAAATCATGAAGAGATAGTTCCACAGTGTCTCAGTTCTGAAGAAACTAAGAACAAAGTTGTATCCTTTCTGGAGAAGACTGGGTTTGTAGATGAAACTGAAGCTGCCAAAGTGGAACGTGTGAAACAGGAAAAAGGTATTTTCTGGGAACCCTTTGCTAATGTGACTGTAGAAGAAGCAAAGAGGTCATCTTTACAGCCTTATGCAAAAAGAGCTCGTCAGGAGTTCCCCTGGGAAGAAGAGTACAGGTCAGCGCTGCATACAATAGCAGGGGCTTTGGAAGCAACTGAGTCACTACTCCAAAAGGGTCCTGCTCCAGCCTGGCTTTCAATGGAAATGGAGGCGCTCCAAGAAAGGATGGATAAGCTAAAACGTTACATACATACTCTAGGGTGA
## 8                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                               Sequence unavailable
## 9                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                               Sequence unavailable
##   ensembl_transcript_id          coding
## 1       ENSG00000000460 ENST00000481744
## 2       ENSG00000000460 ENST00000286031
## 3       ENSG00000000460 ENST00000472795
## 4       ENSG00000000460 ENST00000459772
## 5       ENSG00000000460 ENST00000413811
## 6       ENSG00000000460 ENST00000466580
## 7       ENSG00000000460 ENST00000359326
## 8       ENSG00000000460 ENST00000496973
## 9       ENSG00000000460 ENST00000498289

Visualization

biocLite("ggbio")
biocLite("Homo.sapiens")
library(ggbio)
## Loading required package: ggplot2
## Warning: replacing previous import by 'BiocGenerics::Position' when loading
## 'ggbio'
## Need specific help about ggbio? try mailing 
##  the maintainer or visit http://tengfei.github.com/ggbio/
## 
## Attaching package: 'ggbio'
## The following objects are masked from 'package:ggplot2':
## 
##     geom_bar, geom_rect, geom_segment, ggsave, stat_bin,
##     stat_identity, xlim
library(Homo.sapiens)
## Loading required package: AnnotationDbi
## Loading required package: OrganismDbi
## Loading required package: GenomicFeatures
## Loading required package: GO.db
## Loading required package: DBI
## 
## Loading required package: org.Hs.eg.db
## 
## Loading required package: TxDb.Hsapiens.UCSC.hg19.knownGene
## Now getting the GODb Object directly
## Now getting the OrgDb Object directly
## Now getting the TxDb Object directly

We can try plotting the Granges in our summarized experiment, but the Homo.sapiens object names chromosomes as “chrN”, and the names in airway are just the number.

wh = unlist(rowRanges(airway)[5])
p.g <- autoplot(Homo.sapiens, which=wh)
## Error in .local(obj, ...): 1 is not matched with seqlevels of your object, please rename your 'which' arguments

We need to rename the chromosomes.

wh2 <- renameSeqlevels(wh, sub("1","chr1", seqlevels(wh)))
p.g2 <- autoplot(Homo.sapiens, which=wh2)
## Parsing transcripts...
## Parsing exons...
## Parsing cds...
## Parsing utrs...
## ------exons...
## ------cdss...
## ------introns...
## ------utr...
## aggregating...
## Done
## 'select()' returned 1:1 mapping between keys and columns
## "gap" not in any of the valid gene feature terms "cds", "exon", "utr"
## Constructing graphics...
p.g2
## Warning: Removed 2 rows containing missing values (geom_text).

Analysis

library(limma)
## 
## Attaching package: 'limma'
## The following object is masked from 'package:BiocGenerics':
## 
##     plotMA
design <- model.matrix(~ dex, data=colData(airway))
v <- voom(assays(airway)$counts,design=design)
fit <- lmFit(v, design)
fit <- eBayes(fit)
summary(decideTests(fit))
##    (Intercept) dexuntrt
## -1       49118      674
## 0         1666    62495
## 1        13318      933
topTable(fit, coef="dexuntrt")
##                     logFC  AveExpr         t      P.Value    adj.P.Val
## ENSG00000134686 -1.304196 6.837469 -22.28727 1.384466e-09 8.874707e-05
## ENSG00000148175 -1.364975 8.854588 -18.96349 6.315648e-09 1.428428e-04
## ENSG00000162614 -1.945885 7.636408 -17.51779 1.325278e-08 1.428428e-04
## ENSG00000162616 -1.430717 5.903480 -17.27478 1.509630e-08 1.428428e-04
## ENSG00000189221 -3.263290 5.949117 -16.91641 1.835153e-08 1.428428e-04
## ENSG00000152583 -4.480843 4.165462 -17.88614 1.091355e-08 1.428428e-04
## ENSG00000120129 -2.847874 6.643013 -16.56703 2.228368e-08 1.428428e-04
## ENSG00000178695  2.589942 6.450283  16.57994 2.212289e-08 1.428428e-04
## ENSG00000196517  2.289351 3.024889  17.85198 1.111011e-08 1.428428e-04
## ENSG00000125148 -2.136635 7.022630 -15.98043 3.114408e-08 1.814907e-04
##                         B
## ENSG00000134686 12.547426
## ENSG00000148175 11.263744
## ENSG00000162614 10.516600
## ENSG00000162616 10.307478
## ENSG00000189221 10.103458
## ENSG00000152583 10.049829
## ENSG00000120129  9.977213
## ENSG00000178695  9.974713
## ENSG00000196517  9.831402
## ENSG00000125148  9.673848
plotMA(fit)