README.md

Analyzing Hi-C and HiChIP data with HiCDCPlus

Merve Sahin

05/08/2022

A necessary task in the analysis of HiC or HiChIP count data is the detection of statistically significant and differential genomic interactions. The count data are available as a table which reports, with regions typically as genomic regions binned uniformly or across restriction enzyme fragments, the number of interactions between pairs of genomic regions. The package HiCDCPlus provides methods to determine significant and differential chromatin interactions by use of a negative binomial generalized linear model, as well as implementations for TopDom to call topologically associating domains (TADs), and Juicer eigenvector to find the A/B compartments. This vignette explains the use of the package and demonstrates typical workflows on HiC and HiChIP data. HiCDCPlus package version: 0.99.16 output: html_document: keep_md: true

Note: if you use HiCDCPlus in published research, please cite:

Sahin, M., Wong, W., Zhan, Y., Van Deyze, K., Koche, R., and Leslie, C. S. (2021) HiC-DC+: systematic 3D interaction calls and differential analysis for Hi-C and HiChIP Nature Communications, 12(3366). 10.1038/s41467-021-23749-x

Installation

To install this package, start R and enter:

if (!requireNamespace("BiocManager", quietly = TRUE))
    install.packages("BiocManager")

BiocManager::install("HiCDCPlus")

If you are reinstalling the package, we recommend erasing the associated file cache for the package. The cache folder location can be obtained by running.

cache <- rappdirs::user_cache_dir(appname="HiCDCPlus")
print(cache)

Standard workflow

Overview {#overview}

HiCDCPlus can take the outputs of the popular Hi-C pre-processing tools such as .hic (from Juicebox), .matrix, and .allValidPairs (from HiC-Pro). It can also be used with HTClist objects (from Bioconductor package HiTC).

In the standard workflow, one first needs to generate genomic features present in the HiCDCPlus model (GC content, mappability, effective length) using the construct_features function (see Creating genomic feature files). This can be either done for uniformly or multiple restriction fragment binned data.

HiCDCPlus stores counts and features in a memory-efficient way using what we name as a gi_list instance(see The gi_list instance). One next feeds the genomic features in the form of a gi_list instance using generate_bintolen_gi_list function. Then, counts can be added to this gi_list instance using dedicated functions for each input Hi-C file format (add_hic_counts, add_hicpro_matrix_counts,add_hicpro_allvalidpairs.counts).

Before modeling, 1D features from the gi_list instance coming from the bintolen file must be expanded to 2D using expand_1D_features function. Different transformations can be applied to combine genomic features derived for each anchor.

At the core of HiCDCPlus is an efficient implementation of the HiC-DC negative binomial count model for normalization and removal of biases (see ?HiCDCPlus). A platform-agnostic parallelizable implementation is also available in the HiCDCPlus_parallel function for efficient interaction calling across chromosomes. The HiCDCPlus (or HiCDCPlus_parallel) function outputs the significance of each interaction (pvalue and FDR adjusted p-value qvalue) along with following estimated from the model: 1. mu: expected interaction frequency estimated from biases, 2. sdev: the standard deviation of expected interaction frequencies.

Once results are obtained, they can be output into text files using gi_list_write function or to a .hic file using the hicdc2hicfunction (where one can pass either raw counts, observed/expected normalized counts, -log10 P-value, -log10 P-adjusted value, or negative binomial Z-score normalized counts: (counts-mu)/sdev to the .hic file

To detect differential significant interactions across conditions, HiCDCPlus also provides a modified implementation of DESeq2 using replicate Hi-C/HiChIP datasets hicdcdiff. This function requires a (1) definition of the experimental setup (see ?hicdcdiff), (2) a filtered set of interactions to consider, as a text file containing columns chr, startI, and startJ (startI<=startJ) and (3) count data per each condition and replicate either as gi_list instances or as output text files generated using the gi_list_write function that can be read as valid gi_list instances using gi_list_read. The hicdcdiff function performs the differential analysis and outputs genomic coordinates of pairs of regions with corresponding logFC difference, P-value and BH adjusted P-value (see the example in Quickstart).

We next demonstrate the standard workflow to detect significant as well as differential interactions.

Quickstart {#quickstart}

In this section we show a complete workflow for identifying significant interactions and differential interactions from Hi-C data across replicate experiments. For HiChIP, the functions used are the same, but the distance thresholds used are slightly reduced (recommended Dmax = 1.5e6).

Finding Significant Interactions from Hi-C/HiChIP

Here, we identify significant interactions from HiC data at 50kb resolution across multiple chromosomes (in the example below, across chromosomes 21 and 22). The following example code chunk assumes that you have downloaded a .hic file from GSE63525 and also downloaded Juicebox command line tools. Example below runs with GSE63525_HMEC_combined.hic and stores the path to it into the variable hicfile_path with features generated for restriction enzyme fragments with the pattern "GATC" in hg19 genome.

hicfile_path<-system.file("extdata", "GSE63525_HMEC_combined_example.hic", package = "HiCDCPlus")
outdir<-tempdir(check=TRUE)
#generate features
construct_features(output_path=paste0(outdir,"/hg19_50kb_GATC"),
                   gen="Hsapiens",gen_ver="hg19",
                   sig="GATC",
                   bin_type="Bins-uniform",
                   binsize=50000,
                   chrs=c("chr21","chr22"))
## [1] "Using chr21 chr22and cut patterns GATC"
## [1] "chr21"
## [1] "chr22"
## [1] "/var/folders/31/gz4s1kx132l4_hvgmfc1jl2m0000gn/T//RtmpUrJ86Z/hg19_50kb_GATC_bintolen.txt.gz"

If you have a multiple enzyme cocktail used to generate Hi-C data, you can specify multiple patterns including "N" as string to this function (e.g., sig=c("GATC","GANTC")). If you want to analyze data binned by multiple restriction enzyme fragments, you can change bin_type to "Bins-RE-sites", and binsize to the number of fragments that you would like to merge as bin (e.g., bin_type="Bins-RE-sites" and binsize=10 means 10 restriction fragment binning).

#generate gi_list instance
gi_list<-generate_bintolen_gi_list(
  bintolen_path=paste0(outdir,"/hg19_50kb_GATC_bintolen.txt.gz"))
#add .hic counts
gi_list<-add_hic_counts(gi_list,hic_path = hicfile_path)
## [1] "Chromosome chr21 intrachromosomal counts processed."
## [1] "Chromosome chr22 intrachromosomal counts processed."

If you have HiC-Pro outputs instead, you can use either add_hicpro_matrix_counts or add_hicpro_allvalidpairs.counts depending on the file format. add_hicpro_matrix_counts function requires .bed output from HiC-Pro matrix generation step, together with count data in .matrix format.

#expand features for modeling
gi_list<-expand_1D_features(gi_list)
#run HiC-DC+ on 2 cores
set.seed(1010) #HiC-DC downsamples rows for modeling
gi_list<-HiCDCPlus_parallel(gi_list,ncore=2)
head(gi_list)
## $chr21
## GInteractions object with 18026 interactions and 9 metadata columns:
##           seqnames1           ranges1     seqnames2           ranges2 |
##               <Rle>         <IRanges>         <Rle>         <IRanges> |
##       [1]     chr21   9450000-9500000 ---     chr21  9950000-10000000 |
##       [2]     chr21   9450000-9500000 ---     chr21 10100000-10150000 |
##       [3]     chr21   9450000-9500000 ---     chr21 10150000-10200000 |
##       [4]     chr21   9450000-9500000 ---     chr21 11000000-11050000 |
##       [5]     chr21   9450000-9500000 ---     chr21 11100000-11150000 |
##       ...       ...               ... ...       ...               ... .
##   [18022]     chr21 47900000-47950000 ---     chr21 47900000-47950000 |
##   [18023]     chr21 47900000-47950000 ---     chr21 47950000-48000000 |
##   [18024]     chr21 47900000-47950000 ---     chr21 48000000-48050000 |
##   [18025]     chr21 47900000-47950000 ---     chr21 48050000-48100000 |
##   [18026]     chr21 48000000-48050000 ---     chr21 48000000-48050000 |
##                   D    counts        gc       map       len        mu      sdev
##           <integer> <numeric> <numeric> <numeric> <numeric> <numeric> <numeric>
##       [1]    500000         0 -0.415451         0 0.2861372  36.62682  20.85646
##       [2]    650000         0 -0.767405         0 0.2689031  29.08634  16.74247
##       [3]    700000         0 -0.461107         0 0.2347835  25.74290  14.91746
##       [4]   1550000         0 -0.795873         0 0.0742543   7.95680   5.17270
##       [5]   1650000         0  0.299047         0 0.2230742   8.34009   5.38471
##       ...       ...       ...       ...       ...       ...       ...       ...
##   [18022]         0      2200  0.633416         0 0.4511124  1789.121  975.8642
##   [18023]     50000       545  0.752876         0 0.1295933   537.613  293.8783
##   [18024]    100000       260  0.725338         0 0.3141704   276.445  151.5580
##   [18025]    150000       271  0.570906         0 0.0480836   125.598   69.3535
##   [18026]         0      2709  0.817260         0 0.1772284  1484.744  809.9996
##              pvalue    qvalue
##           <numeric> <numeric>
##       [1]         1         1
##       [2]         1         1
##       [3]         1         1
##       [4]         1         1
##       [5]         1         1
##       ...       ...       ...
##   [18022] 0.2837514  0.857618
##   [18023] 0.4184339  0.922653
##   [18024] 0.4722949  0.942038
##   [18025] 0.0386625  0.387830
##   [18026] 0.0811332  0.562719
##   -------
##   regions: 963 ranges and 3 metadata columns
##   seqinfo: 1 sequence from an unspecified genome; no seqlengths
## 
## $chr22
## GInteractions object with 18241 interactions and 9 metadata columns:
##           seqnames1           ranges1     seqnames2           ranges2 |
##               <Rle>         <IRanges>         <Rle>         <IRanges> |
##       [1]     chr22 16050000-16100000 ---     chr22 17650000-17700000 |
##       [2]     chr22 16050000-16100000 ---     chr22 17700000-17750000 |
##       [3]     chr22 16050000-16100000 ---     chr22 17800000-17850000 |
##       [4]     chr22 16050000-16100000 ---     chr22 17950000-18000000 |
##       [5]     chr22 16050000-16100000 ---     chr22 18000000-18050000 |
##       ...       ...               ... ...       ...               ... .
##   [18237]     chr22 51000000-51050000 ---     chr22 51100000-51150000 |
##   [18238]     chr22 51000000-51050000 ---     chr22 51150000-51200000 |
##   [18239]     chr22 51050000-51100000 ---     chr22 51050000-51100000 |
##   [18240]     chr22 51050000-51100000 ---     chr22 51150000-51200000 |
##   [18241]     chr22 51150000-51200000 ---     chr22 51150000-51200000 |
##                   D    counts         gc       map       len        mu
##           <integer> <numeric>  <numeric> <numeric> <numeric> <numeric>
##       [1]   1600000         1  0.0731079         0 0.1565584   6.52084
##       [2]   1650000         3  0.0445727         0 0.0809363   5.78804
##       [3]   1750000         3 -0.2745115         0 0.0120789   4.57491
##       [4]   1900000         0 -0.6320482         0 0.0357296   3.31760
##       [5]   1950000         1 -0.2308528         0 0.1088195   3.23818
##       ...       ...       ...        ...       ...       ...       ...
##   [18237]    100000       477   1.350818         0 0.1560164   414.965
##   [18238]    150000       269   1.113756         0 0.3827365   246.312
##   [18239]         0      3903   0.440179         0 0.1683074  2610.342
##   [18240]    100000       350   0.540858         0 0.0930645   361.689
##   [18241]         0      2665   0.641536         0 0.0178216  2415.709
##                sdev    pvalue    qvalue
##           <numeric> <numeric> <numeric>
##       [1]   4.31807  0.974889         1
##       [2]   3.91674  0.795263         1
##       [3]   3.24700  0.704750         1
##       [4]   2.54088  1.000000         1
##       [5]   2.49563  0.899118         1
##       ...       ...       ...       ...
##   [18237]   222.523  0.329603  1.000000
##   [18238]   132.462  0.366718  1.000000
##   [18239]  1394.840  0.163675  0.950785
##   [18240]   194.074  0.453822  1.000000
##   [18241]  1290.907  0.357891  1.000000
##   -------
##   regions: 1027 ranges and 3 metadata columns
##   seqinfo: 1 sequence from an unspecified genome; no seqlengths
#write normalized counts (observed/expected) to a .hic file
hicdc2hic(gi_list,hicfile=paste0(outdir,'/GSE63525_HMEC_combined_result.hic'),
          mode='normcounts',gen_ver='hg19')
## [1] "/var/folders/31/gz4s1kx132l4_hvgmfc1jl2m0000gn/T//RtmpUrJ86Z/GSE63525_HMEC_combined_result.hic"
#write results to a text file
gi_list_write(gi_list,fname=paste0(outdir,'/GSE63525_HMEC_combined_result.txt.gz'))
## [1] "/var/folders/31/gz4s1kx132l4_hvgmfc1jl2m0000gn/T//RtmpUrJ86Z/GSE63525_HMEC_combined_result.txt.gz"

HiCDCPlus results can be converted into .hic using hicdc2hic function. Values that should be supplied as "mode" into the hicdc2hic function for the corresponding score stored in the .hic file are: 'pvalue' for -log10 significance p-value, 'qvalue' for -log10 FDR corrected p-value, 'normcounts' for raw counts/expected counts, 'zvalue' for standardized counts (raw counts-expected counts)/modeled standard deviation of expected counts and 'raw' to pass-through raw counts.

.hic files can be further converted into .cool format using hic2cool software and be visualized using HiCExplorer.

Finding Differential Interactions {#diff_int}

Suppose we're interested in finding differential interactions on chr21 and chr22 at 50kb between NSD2 and NTKO/TKO cells given the following .hic files available in GSE131651: GSE131651_NSD2_LOW_arima.hic, GSE131651_NSD2_HIGH_arima.hic, GSE131651_TKOCTCF_new.hic, GSE131651_NTKOCTCF_new.hic. We first find significant interactions in each, and save results to a file:

#generate features
construct_features(output_path=paste0(outdir,"/hg38_50kb_GATC"),
                   gen="Hsapiens",gen_ver="hg38",
                   sig="GATC",bin_type="Bins-uniform",
                   binsize=50000,
                   chrs=c("chr21","chr22"))
## [1] "Using chr21 chr22and cut patterns GATC"
## [1] "chr21"
## [1] "chr22"
## [1] "/var/folders/31/gz4s1kx132l4_hvgmfc1jl2m0000gn/T//RtmpUrJ86Z/hg38_50kb_GATC_bintolen.txt.gz"
#add .hic counts
hicfile_paths<-c(
system.file("extdata", "GSE131651_NSD2_LOW_arima_example.hic", package = "HiCDCPlus"),
system.file("extdata", "GSE131651_NSD2_HIGH_arima_example.hic", package = "HiCDCPlus"),
system.file("extdata", "GSE131651_TKOCTCF_new_example.hic", package = "HiCDCPlus"),
system.file("extdata", "GSE131651_NTKOCTCF_new_example.hic", package = "HiCDCPlus"))
indexfile<-data.frame()
for(hicfile_path in hicfile_paths){
output_path<-paste0(outdir,'/',
                    gsub("^(.*[\\/])", "",gsub('.hic','.txt.gz',hicfile_path)))
#generate gi_list instance
gi_list<-generate_bintolen_gi_list(
  bintolen_path=paste0(outdir,"/hg38_50kb_GATC_bintolen.txt.gz"),
  gen="Hsapiens",gen_ver="hg38")
gi_list<-add_hic_counts(gi_list,hic_path = hicfile_path)
#expand features for modeling
gi_list<-expand_1D_features(gi_list)
#run HiC-DC+ on 2 cores
set.seed(1010) #HiC-DC downsamples rows for modeling
gi_list<-HiCDCPlus(gi_list,ssize=0.1)
for (i in seq(length(gi_list))){
indexfile<-unique(rbind(indexfile,
  as.data.frame(gi_list[[i]][gi_list[[i]]$qvalue<=0.05])[c('seqnames1',
                                                           'start1','start2')]))
}
#write results to a text file
gi_list_write(gi_list,fname=output_path)
}
## Warning in add_2D_features(gi_list[[chrom]], count_matrix): Bins and counts mismatch. This will slow down the
##             performance of counts integration.Check if genome and/or bin size of
##             counts data is aligned with the GenomicInteractions object.
## [1] "Chromosome chr21 intrachromosomal counts processed."
## Warning in add_2D_features(gi_list[[chrom]], count_matrix): Bins and counts mismatch. This will slow down the
##             performance of counts integration.Check if genome and/or bin size of
##             counts data is aligned with the GenomicInteractions object.
## [1] "Chromosome chr22 intrachromosomal counts processed."
## [1] "Chromosome chr21 complete."
## [1] "Chromosome chr22 complete."
## [1] "Chromosome chr21 intrachromosomal counts processed."
## [1] "Chromosome chr22 intrachromosomal counts processed."
## [1] "Chromosome chr21 complete."
## [1] "Chromosome chr22 complete."
## [1] "Chromosome chr21 intrachromosomal counts processed."
## [1] "Chromosome chr22 intrachromosomal counts processed."
## [1] "Chromosome chr21 complete."
## [1] "Chromosome chr22 complete."
## [1] "Chromosome chr21 intrachromosomal counts processed."
## [1] "Chromosome chr22 intrachromosomal counts processed."
## [1] "Chromosome chr21 complete."
## [1] "Chromosome chr22 complete."
#save index file---union of significants at 50kb
colnames(indexfile)<-c('chr','startI','startJ')
data.table::fwrite(indexfile,
            paste0(outdir,'/GSE131651_analysis_indices.txt.gz'),
            sep='\t',row.names=FALSE,quote=FALSE)

We next get the union set of significant interactions and save it as the index file, and then run hicdcdiff.

#Differential analysis using modified DESeq2 (see ?hicdcdiff)
hicdcdiff(input_paths=list(NSD2=c(paste0(outdir,'/GSE131651_NSD2_LOW_arima_example.txt.gz'),
                 paste0(outdir,'/GSE131651_NSD2_HIGH_arima_example.txt.gz')),
TKO=c(paste0(outdir,'/GSE131651_TKOCTCF_new_example.txt.gz'),
paste0(outdir,'/GSE131651_NTKOCTCF_new_example.txt.gz'))),
filter_file=paste0(outdir,'/GSE131651_analysis_indices.txt.gz'),
output_path=paste0(outdir,'/diff_analysis_example/'),
fitType = 'mean',
binsize=50000,
diagnostics=TRUE)
## $deseq2paths
## NULL
## 
## $outputpaths
## [1] "/var/folders/31/gz4s1kx132l4_hvgmfc1jl2m0000gn/T//RtmpUrJ86Z/diff_analysis_example/diff_resTKOoverNSD2_chr21.txt.gz"
## [2] "/var/folders/31/gz4s1kx132l4_hvgmfc1jl2m0000gn/T//RtmpUrJ86Z/diff_analysis_example/diff_resTKOoverNSD2_chr22.txt.gz"
## 
## $plotpaths
##  [1] "/var/folders/31/gz4s1kx132l4_hvgmfc1jl2m0000gn/T//RtmpUrJ86Z/diff_analysis_example/sizefactors_chr21.pdf"        
##  [2] "/var/folders/31/gz4s1kx132l4_hvgmfc1jl2m0000gn/T//RtmpUrJ86Z/diff_analysis_example/geomean_sizefactors_chr21.pdf"
##  [3] "/var/folders/31/gz4s1kx132l4_hvgmfc1jl2m0000gn/T//RtmpUrJ86Z/diff_analysis_example/plotMA_TKOoverNSD2_chr21.pdf" 
##  [4] "/var/folders/31/gz4s1kx132l4_hvgmfc1jl2m0000gn/T//RtmpUrJ86Z/diff_analysis_example/diff_chr21_PCA.pdf"           
##  [5] "/var/folders/31/gz4s1kx132l4_hvgmfc1jl2m0000gn/T//RtmpUrJ86Z/diff_analysis_example/dispersionplot.pdf"           
##  [6] "/var/folders/31/gz4s1kx132l4_hvgmfc1jl2m0000gn/T//RtmpUrJ86Z/diff_analysis_example/sizefactors_chr22.pdf"        
##  [7] "/var/folders/31/gz4s1kx132l4_hvgmfc1jl2m0000gn/T//RtmpUrJ86Z/diff_analysis_example/geomean_sizefactors_chr22.pdf"
##  [8] "/var/folders/31/gz4s1kx132l4_hvgmfc1jl2m0000gn/T//RtmpUrJ86Z/diff_analysis_example/plotMA_TKOoverNSD2_chr22.pdf" 
##  [9] "/var/folders/31/gz4s1kx132l4_hvgmfc1jl2m0000gn/T//RtmpUrJ86Z/diff_analysis_example/diff_chr22_PCA.pdf"           
## [10] "/var/folders/31/gz4s1kx132l4_hvgmfc1jl2m0000gn/T//RtmpUrJ86Z/diff_analysis_example/dispersionplot.pdf"
#Check the generated plots as well as DESeq2 results

Suppose you provide multiple conditions in input_paths such as input_paths=list(A="..",B="..",C=".."), then the pairwise comparisons reported by hicdcdiff will be B over A, C over B, C over A.

ICE normalization using HiTC {#ice}

To find TADs, we use ICE normalized Hi-C data. If you use HiC-Pro to process counts, we suggest feeding ICE normalized .matrix files into a gi_list instance.

gi_list<-generate_binned_gi_list(50000,chrs=c("chr21","chr22"))
gi_list<-add_hicpro_matrix.counts(gi_list,absfile_path,matrixfile_path,chrs=c("chr21","chr22")) #add paths to iced absfile and matrix files here

If you have .hic file instead, then you can perform ICE normalization with our HiTC wrapper as follows:

hic_path<-system.file("extdata", "GSE63525_HMEC_combined_example.hic", package = "HiCDCPlus")
gi_list=hic2icenorm_gi_list(hic_path,binsize=50e3,chrs=c('chr21','chr22'))

You can also output a ICE normalized .hic file to the path gsub(".hic","_icenorm.hic",hic_path) from hic2icenorm_gi_list if you set hic_out=TRUE to your call to this function.

Finding TADs using TopDom {#topdom}

HiCDCPlus converts the gi_list instance with ICE normalized counts into TAD annotations through an implementation of TopDom v0.0.2 (https://github.com/HenrikBengtsson/TopDom) adapted as TopDom. We recommend call TADs with to ICE normalized counts at 50kb resolution with window.size 10 in TopDom.

tads<-gi_list_topdom(gi_list,chrs=c("chr21","chr22"),window.size = 10)
## [1] "#########################################################################"
## [1] "Step 0 : File Read "
## [1] "#########################################################################"
## [1] "-- Done!"
## [1] "Step 0 : Done !!"
## [1] "#########################################################################"
## [1] "Step 1 : Generating binSignals by computing bin-level contact frequencies"
## [1] "#########################################################################"
## [1] "Step 1 Running Time :  0.00400000000000489"
## [1] "Step 1 : Done !!"
## [1] "#########################################################################"
## [1] "Step 2 : Detect TD boundaries based on binSignals"
## [1] "#########################################################################"
## [1] "Process Regions from  1 to 665"
## [1] "Step 2 Running Time :  0.00499999999999545"
## [1] "Step 2 : Done !!"
## [1] "#########################################################################"
## [1] "Step 3 : Statistical Filtering of false positive TD boundaries"
## [1] "#########################################################################"
## [1] "-- Matrix Scaling...."
## [1] "-- Compute p-values by Wilcox Ranksum Test"
## [1] "Process Regions from  1 to 665"
## [1] "-- Done!"
## [1] "-- Filtering False Positives"
## [1] "-- Done!"
## [1] "Step 3 Running Time :  0.298000000000002"
## [1] "Step 3 : Done!"
## [1] "Done!!"
## [1] "Job Complete !"
## [1] "#########################################################################"
## [1] "Step 0 : File Read "
## [1] "#########################################################################"
## [1] "-- Done!"
## [1] "Step 0 : Done !!"
## [1] "#########################################################################"
## [1] "Step 1 : Generating binSignals by computing bin-level contact frequencies"
## [1] "#########################################################################"
## [1] "Step 1 Running Time :  0.00400000000000489"
## [1] "Step 1 : Done !!"
## [1] "#########################################################################"
## [1] "Step 2 : Detect TD boundaries based on binSignals"
## [1] "#########################################################################"
## [1] "Process Regions from  1 to 675"
## [1] "Step 2 Running Time :  0.00499999999999545"
## [1] "Step 2 : Done !!"
## [1] "#########################################################################"
## [1] "Step 3 : Statistical Filtering of false positive TD boundaries"
## [1] "#########################################################################"
## [1] "-- Matrix Scaling...."
## [1] "-- Compute p-values by Wilcox Ranksum Test"
## [1] "Process Regions from  1 to 675"
## [1] "-- Done!"
## [1] "-- Filtering False Positives"
## [1] "-- Done!"
## [1] "Step 3 Running Time :  0.385000000000005"
## [1] "Step 3 : Done!"
## [1] "Done!!"
## [1] "Job Complete !"

Finding A/B compartment using Juicer {#comp}

HiCDCPlus can call Juicer eigenvector function to determine A/B compartments from .hic files. extract_hic_eigenvectors generates text files for each chromosome containing chromosome, start, end and compartment score values that may need to be flipped signs for each chromosome. File paths follow gsub('.hic','__eigenvalues.txt',hicfile).

extract_hic_eigenvectors(
  hicfile=system.file("extdata", "eigenvector_example.hic", package = "HiCDCPlus"),
  mode = "KR",
  binsize = 50e3,
  chrs = "chr22",
  gen = "Hsapiens",
  gen_ver = "hg19",
  mode = "NONE"
)

Creating genomic feature files {#bintolen}

Genomic features can be generated using the construct_features function. This function finds all restriction enzyme cutsites of a given genome and genome version and computes GC content, mappability (if a relevant .bigWig file is provided) and effective fragment length for uniform bin or across specified multiples of restriction enzyme cutsites of given pattern(s).

#generate features
construct_features(output_path=paste0(outdir,"/hg19_50kb_GATC"),
                   gen="Hsapiens",gen_ver="hg19",
                   sig=c("GATC","GANTC"),bin_type="Bins-uniform",
                   binsize=50000,
                   wg_file=NULL, #e.g., 'hg19_wgEncodeCrgMapabilityAlign50mer.bigWig',
                   chrs=c("chr21","chr22"))
## [1] "Using chr21 chr22and cut patterns GATC GANTC"
## [1] "chr21"
## [1] "chr22"
## [1] "/var/folders/31/gz4s1kx132l4_hvgmfc1jl2m0000gn/T//RtmpUrJ86Z/hg19_50kb_GATC_bintolen.txt.gz"
#read and print
bintolen<-data.table::fread(paste0(outdir,"/hg19_50kb_GATC_bintolen.txt.gz"))
tail(bintolen,20)
##                        bins     gc map   len
##  1: chr22-49850001-49900000 0.4833   0 49875
##  2: chr22-49900001-49950000 0.5126   0 47521
##  3: chr22-49950001-50000000 0.5139   0 46220
##  4: chr22-50000001-50050000 0.5472   0 48270
##  5: chr22-50050001-50100000 0.5241   0 49289
##  6: chr22-50100001-50150000 0.5014   0 49584
##  7: chr22-50150001-50200000 0.5466   0 48171
##  8: chr22-50200001-50250000 0.5232   0 47970
##  9: chr22-50250001-50300000 0.4675   0 49242
## 10: chr22-50300001-50350000 0.6117   0 41993
## 11: chr22-50350001-50400000 0.1997   0 49875
## 12: chr22-50400001-50450000 0.3623   0 47683
## 13: chr22-50450001-50500000 0.5526   0 49544
## 14: chr22-50500001-50550000 0.5126   0 49105
## 15: chr22-50550001-50600000 0.4790   0 49875
## 16: chr22-50600001-50650000 0.6103   0 49700
## 17: chr22-50650001-50700000 0.5927   0 49531
## 18: chr22-50700001-50750000 0.6473   0 49469
## 19: chr22-50750001-50800000 0.5409   0 49669
## 20: chr22-50800001-50818468 0.4792   0  7806

The gi_list instance {#gi_list}

HiCDCPlus stores features and count data in a list of InteractionSet objects generated for each chromosome, what we name as a gi_list instance.

A gi_list instance can be initialized through multiple ways. One can generate a uniformly binsized gi_list instance using generate_binned_gi_list. One can also generate a restriction enzyme fragment binning of the genome as a data.frame and ingest it as a gi_list instance (see ?generate_df_gi_list) Third, one can generate some genomic features (GC content, mappability, effective length) and restriction enzyme fragment regions into as a bintolen file (see Creating bintolen files) and generate a gi_list instance from this bintolen file. Finally, one can read a gi_list instance from a file generated by gi_list_write (see ?gi_list_read).

Uniformly binned gi_list instance {#uniform}

One can generate a uniform binsized gi_list instance for a genome using generate_binned_gi_list:

gi_list<-generate_binned_gi_list(binsize=50000,chrs=c('chr20','chr21'),
                                 gen="Hsapiens",gen_ver="hg19")
head(gi_list)
## $chr20
## GInteractions object with 52029 interactions and 1 metadata column:
##           seqnames1           ranges1     seqnames2           ranges2 |
##               <Rle>         <IRanges>         <Rle>         <IRanges> |
##       [1]     chr20           0-50000 ---     chr20           0-50000 |
##       [2]     chr20           0-50000 ---     chr20      50000-100000 |
##       [3]     chr20           0-50000 ---     chr20     100000-150000 |
##       [4]     chr20           0-50000 ---     chr20     150000-200000 |
##       [5]     chr20           0-50000 ---     chr20     200000-250000 |
##       ...       ...               ... ...       ...               ... .
##   [52025]     chr20 64300000-64350000 ---     chr20 64350000-64400000 |
##   [52026]     chr20 64300000-64350000 ---     chr20 64400000-64444167 |
##   [52027]     chr20 64350000-64400000 ---     chr20 64350000-64400000 |
##   [52028]     chr20 64350000-64400000 ---     chr20 64400000-64444167 |
##   [52029]     chr20 64400000-64444167 ---     chr20 64400000-64444167 |
##                   D
##           <integer>
##       [1]         0
##       [2]     50000
##       [3]    100000
##       [4]    150000
##       [5]    200000
##       ...       ...
##   [52025]     50000
##   [52026]     97083
##   [52027]         0
##   [52028]     47083
##   [52029]         0
##   -------
##   regions: 1289 ranges and 0 metadata columns
##   seqinfo: 1 sequence from an unspecified genome; no seqlengths
## 
## $chr21
## GInteractions object with 37515 interactions and 1 metadata column:
##           seqnames1           ranges1     seqnames2           ranges2 |
##               <Rle>         <IRanges>         <Rle>         <IRanges> |
##       [1]     chr21           0-50000 ---     chr21           0-50000 |
##       [2]     chr21           0-50000 ---     chr21      50000-100000 |
##       [3]     chr21           0-50000 ---     chr21     100000-150000 |
##       [4]     chr21           0-50000 ---     chr21     150000-200000 |
##       [5]     chr21           0-50000 ---     chr21     200000-250000 |
##       ...       ...               ... ...       ...               ... .
##   [37511]     chr21 46600000-46650000 ---     chr21 46650000-46700000 |
##   [37512]     chr21 46600000-46650000 ---     chr21 46700000-46709983 |
##   [37513]     chr21 46650000-46700000 ---     chr21 46650000-46700000 |
##   [37514]     chr21 46650000-46700000 ---     chr21 46700000-46709983 |
##   [37515]     chr21 46700000-46709983 ---     chr21 46700000-46709983 |
##                   D
##           <integer>
##       [1]         0
##       [2]     50000
##       [3]    100000
##       [4]    150000
##       [5]    200000
##       ...       ...
##   [37511]     50000
##   [37512]     79991
##   [37513]         0
##   [37514]     29991
##   [37515]         0
##   -------
##   regions: 935 ranges and 0 metadata columns
##   seqinfo: 1 sequence from an unspecified genome; no seqlengths

Restriction enzyme binned gi_list instance {#re_sites}

One can also generate an restriction enzyme fragment binning (indeed, any arbitrary binning) of the genome containing columns named chr and start as a data.frame (e.g., a data.frame read from a .bed file) and use it to generate a gi_list instance using generate_df_gi_list.

df<-data.frame(chr='chr9',start=c(1,300,7867,103938))
gi_list<-generate_df_gi_list(df)
gi_list
## $chr9
## GInteractions object with 7 interactions and 1 metadata column:
##       seqnames1          ranges1     seqnames2          ranges2 |         D
##           <Rle>        <IRanges>         <Rle>        <IRanges> | <integer>
##   [1]      chr9            1-300 ---      chr9            1-300 |         0
##   [2]      chr9            1-300 ---      chr9         300-7867 |      3933
##   [3]      chr9            1-300 ---      chr9      7867-103938 |     55752
##   [4]      chr9         300-7867 ---      chr9         300-7867 |         0
##   [5]      chr9         300-7867 ---      chr9      7867-103938 |     51819
##   [6]      chr9      7867-103938 ---      chr9      7867-103938 |         0
##   [7]      chr9 103938-138394717 ---      chr9 103938-138394717 |         0
##   -------
##   regions: 4 ranges and 0 metadata columns
##   seqinfo: 1 sequence from an unspecified genome; no seqlengths

Generating gi_list instance from a bintolen file

One can generate genomic features (gc, mappability, effective length) and restriction enzyme fragment regions as a bintolen file (see Creating bintolen files) first and then generate a gi_list instance from it. This instance will readily store genomic features of the bintolen file.

#generate features
construct_features(output_path=paste0(outdir,"/hg19_50kb_GATC"),
                   gen="Hsapiens",gen_ver="hg19",
                   sig="GATC",bin_type="Bins-uniform",
                   binsize=50000,
            wg_file=NULL, #e.g., 'hg19_wgEncodeCrgMapabilityAlign50mer.bigWig',
                   chrs=c("chr21","chr22"))
## [1] "Using chr21 chr22and cut patterns GATC"
## [1] "chr21"
## [1] "chr22"
## [1] "/var/folders/31/gz4s1kx132l4_hvgmfc1jl2m0000gn/T//RtmpUrJ86Z/hg19_50kb_GATC_bintolen.txt.gz"
#generate gi_list instance
gi_list<-generate_bintolen_gi_list(
  bintolen_path=paste0(outdir,"/hg19_50kb_GATC_bintolen.txt.gz"))
head(gi_list)
## $chr21
## GInteractions object with 37515 interactions and 1 metadata column:
##           seqnames1           ranges1     seqnames2           ranges2 |
##               <Rle>         <IRanges>         <Rle>         <IRanges> |
##       [1]     chr21           0-50000 ---     chr21           0-50000 |
##       [2]     chr21           0-50000 ---     chr21      50000-100000 |
##       [3]     chr21           0-50000 ---     chr21     100000-150000 |
##       [4]     chr21           0-50000 ---     chr21     150000-200000 |
##       [5]     chr21           0-50000 ---     chr21     200000-250000 |
##       ...       ...               ... ...       ...               ... .
##   [37511]     chr21 46600000-46650000 ---     chr21 46650000-46700000 |
##   [37512]     chr21 46600000-46650000 ---     chr21 46700000-46709983 |
##   [37513]     chr21 46650000-46700000 ---     chr21 46650000-46700000 |
##   [37514]     chr21 46650000-46700000 ---     chr21 46700000-46709983 |
##   [37515]     chr21 46700000-46709983 ---     chr21 46700000-46709983 |
##                   D
##           <integer>
##       [1]         0
##       [2]     50000
##       [3]    100000
##       [4]    150000
##       [5]    200000
##       ...       ...
##   [37511]     50000
##   [37512]     79991
##   [37513]         0
##   [37514]     29991
##   [37515]         0
##   -------
##   regions: 935 ranges and 3 metadata columns
##   seqinfo: 1 sequence from an unspecified genome; no seqlengths
## 
## $chr22
## GInteractions object with 40877 interactions and 1 metadata column:
##           seqnames1           ranges1     seqnames2           ranges2 |
##               <Rle>         <IRanges>         <Rle>         <IRanges> |
##       [1]     chr22           0-50000 ---     chr22           0-50000 |
##       [2]     chr22           0-50000 ---     chr22      50000-100000 |
##       [3]     chr22           0-50000 ---     chr22     100000-150000 |
##       [4]     chr22           0-50000 ---     chr22     150000-200000 |
##       [5]     chr22           0-50000 ---     chr22     200000-250000 |
##       ...       ...               ... ...       ...               ... .
##   [40873]     chr22 50700000-50750000 ---     chr22 50750000-50800000 |
##   [40874]     chr22 50700000-50750000 ---     chr22 50800000-50818468 |
##   [40875]     chr22 50750000-50800000 ---     chr22 50750000-50800000 |
##   [40876]     chr22 50750000-50800000 ---     chr22 50800000-50818468 |
##   [40877]     chr22 50800000-50818468 ---     chr22 50800000-50818468 |
##                   D
##           <integer>
##       [1]         0
##       [2]     50000
##       [3]    100000
##       [4]    150000
##       [5]    200000
##       ...       ...
##   [40873]     50000
##   [40874]     84234
##   [40875]         0
##   [40876]     34234
##   [40877]         0
##   -------
##   regions: 1017 ranges and 3 metadata columns
##   seqinfo: 1 sequence from an unspecified genome; no seqlengths

Using custom features with HiCDCPlus

HiCDCPlus allows modeling with user-defined 1D (genomic features for each bin) and 2D (features belonging to an interaction) features.

Once a gi_list instance is at hand, one can ingest counts (and 2D features) using a sparse matrix format text file containing chr, startI, startJ and <featurename> columns (see ?add_2D_features) for features you would like to add. counts can be ingested this way as well provided you have a text file containing columns named chr, startI and startJ.

df<-data.frame(chr='chr9',start=seq(1e6,10e6,1e6))
gi_list<-generate_df_gi_list(df,Dthreshold=500e3,chrs="chr9")
feats<-data.frame(chr='chr9',
startI=seq(1e6,10e6,1e6),
startJ=seq(1e6,10e6,1e6),
counts=rpois(20,lambda=5))
gi_list[['chr9']]<-add_2D_features(gi_list[['chr9']],feats)
gi_list
## $chr9
## GInteractions object with 10 interactions and 2 metadata columns:
##        seqnames1            ranges1     seqnames2            ranges2 |
##            <Rle>          <IRanges>         <Rle>          <IRanges> |
##    [1]      chr9    1000000-2000000 ---      chr9    1000000-2000000 |
##    [2]      chr9    2000000-3000000 ---      chr9    2000000-3000000 |
##    [3]      chr9    3000000-4000000 ---      chr9    3000000-4000000 |
##    [4]      chr9    4000000-5000000 ---      chr9    4000000-5000000 |
##    [5]      chr9    5000000-6000000 ---      chr9    5000000-6000000 |
##    [6]      chr9    6000000-7000000 ---      chr9    6000000-7000000 |
##    [7]      chr9    7000000-8000000 ---      chr9    7000000-8000000 |
##    [8]      chr9    8000000-9000000 ---      chr9    8000000-9000000 |
##    [9]      chr9   9000000-10000000 ---      chr9   9000000-10000000 |
##   [10]      chr9 10000000-138394717 ---      chr9 10000000-138394717 |
##                D    counts
##        <integer> <numeric>
##    [1]         0         9
##    [2]         0        10
##    [3]         0         4
##    [4]         0         8
##    [5]         0         4
##    [6]         0        12
##    [7]         0         9
##    [8]         0         6
##    [9]         0        10
##   [10]         0        10
##   -------
##   regions: 10 ranges and 0 metadata columns
##   seqinfo: 1 sequence from an unspecified genome; no seqlengths

One can also ingest 1D features using a sparse matrix format text file containing chr, start and <featurename> (see ?add_1D_features) and broadcast 1D features to 2D for modeling using a user-specified function (see ?expand_1D_features). Ingesting 1D features first and then expanding has a better memory footprint compared to using add_2D_features directly.

df<-data.frame(chr='chr9',start=seq(1e6,10e6,1e6),end=seq(2e6,11e6,1e6))
gi_list<-generate_df_gi_list(df)
feats<-data.frame(chr='chr9',start=seq(1e6,10e6,1e6),gc=runif(10))
gi_list<-add_1D_features(gi_list,feats)
gi_list
## $chr9
## GInteractions object with 27 interactions and 1 metadata column:
##        seqnames1           ranges1     seqnames2           ranges2 |         D
##            <Rle>         <IRanges>         <Rle>         <IRanges> | <integer>
##    [1]      chr9   1000000-2000000 ---      chr9   1000000-2000000 |         0
##    [2]      chr9   1000000-2000000 ---      chr9   2000000-3000000 |   1000000
##    [3]      chr9   1000000-2000000 ---      chr9   3000000-4000000 |   2000000
##    [4]      chr9   2000000-3000000 ---      chr9   2000000-3000000 |         0
##    [5]      chr9   2000000-3000000 ---      chr9   3000000-4000000 |   1000000
##    ...       ...               ... ...       ...               ... .       ...
##   [23]      chr9   8000000-9000000 ---      chr9  9000000-10000000 |   1000000
##   [24]      chr9   8000000-9000000 ---      chr9 10000000-11000000 |   2000000
##   [25]      chr9  9000000-10000000 ---      chr9  9000000-10000000 |         0
##   [26]      chr9  9000000-10000000 ---      chr9 10000000-11000000 |   1000000
##   [27]      chr9 10000000-11000000 ---      chr9 10000000-11000000 |         0
##   -------
##   regions: 10 ranges and 1 metadata column
##   seqinfo: 1 sequence from an unspecified genome; no seqlengths
mcols(InteractionSet::regions(gi_list[['chr9']]))
## DataFrame with 10 rows and 1 column
##           gc
##    <numeric>
## 1   0.396247
## 2   0.478465
## 3   0.393194
## 4   0.568527
## 5   0.232949
## 6   0.316447
## 7   0.331840
## 8   0.799278
## 9   0.778489
## 10  0.280763
gi_list<-expand_1D_features(gi_list)
gi_list
## $chr9
## GInteractions object with 27 interactions and 2 metadata columns:
##        seqnames1           ranges1     seqnames2           ranges2 |         D
##            <Rle>         <IRanges>         <Rle>         <IRanges> | <integer>
##    [1]      chr9   1000000-2000000 ---      chr9   1000000-2000000 |         0
##    [2]      chr9   1000000-2000000 ---      chr9   2000000-3000000 |   1000000
##    [3]      chr9   1000000-2000000 ---      chr9   3000000-4000000 |   2000000
##    [4]      chr9   2000000-3000000 ---      chr9   2000000-3000000 |         0
##    [5]      chr9   2000000-3000000 ---      chr9   3000000-4000000 |   1000000
##    ...       ...               ... ...       ...               ... .       ...
##   [23]      chr9   8000000-9000000 ---      chr9  9000000-10000000 |   1000000
##   [24]      chr9   8000000-9000000 ---      chr9 10000000-11000000 |   2000000
##   [25]      chr9  9000000-10000000 ---      chr9  9000000-10000000 |         0
##   [26]      chr9  9000000-10000000 ---      chr9 10000000-11000000 |   1000000
##   [27]      chr9 10000000-11000000 ---      chr9 10000000-11000000 |         0
##                gc
##         <numeric>
##    [1] -0.2104882
##    [2]  0.0814864
##    [3] -0.2224653
##    [4]  0.3734610
##    [5]  0.0695092
##    ...        ...
##   [23]   1.921865
##   [24]   0.342575
##   [25]   1.881054
##   [26]   0.301764
##   [27]  -1.277526
##   -------
##   regions: 10 ranges and 1 metadata column
##   seqinfo: 1 sequence from an unspecified genome; no seqlengths

How to get help for HiCDCPlus

Any and all HiCDCPlus questions should be posted to the Bioconductor support site, which serves as a searchable knowledge base of questions and answers:

https://support.bioconductor.org

Posting a question and tagging with "HiCDCPlus" or "HiC-DC+" will automatically send an alert to the package authors to respond on the support site. You should not email your question to the package authors directly, as we will just reply that the question should be posted to the Bioconductor support site instead.

Session info

sessionInfo()
## R version 4.0.2 (2020-06-22)
## Platform: x86_64-apple-darwin17.0 (64-bit)
## Running under: macOS Catalina 10.15.7
## 
## Matrix products: default
## BLAS:   /Library/Frameworks/R.framework/Versions/4.0/Resources/lib/libRblas.dylib
## LAPACK: /Library/Frameworks/R.framework/Versions/4.0/Resources/lib/libRlapack.dylib
## 
## locale:
## [1] en_US.UTF-8/en_US.UTF-8/en_US.UTF-8/C/en_US.UTF-8/en_US.UTF-8
## 
## attached base packages:
## [1] stats4    parallel  stats     graphics  grDevices utils     datasets 
## [8] methods   base     
## 
## other attached packages:
##  [1] BSgenome.Hsapiens.UCSC.hg38_1.4.3 BSgenome.Hsapiens.UCSC.hg19_1.4.3
##  [3] BSgenome_1.56.0                   rtracklayer_1.48.0               
##  [5] Biostrings_2.56.0                 XVector_0.28.0                   
##  [7] GenomicRanges_1.40.0              GenomeInfoDb_1.24.2              
##  [9] IRanges_2.22.2                    S4Vectors_0.26.1                 
## [11] BiocGenerics_0.34.0               HiCDCPlus_0.2.0                  
## 
## loaded via a namespace (and not attached):
##   [1] colorspace_1.4-1            ellipsis_0.3.1             
##   [3] biovizBase_1.36.0           htmlTable_2.1.0            
##   [5] base64enc_0.1-3             dichromat_2.0-0            
##   [7] rstudioapi_0.11             farver_2.0.3               
##   [9] bit64_4.0.5                 AnnotationDbi_1.50.3       
##  [11] splines_4.0.2               R.methodsS3_1.8.1          
##  [13] geneplotter_1.66.0          knitr_1.30                 
##  [15] Formula_1.2-3               Rsamtools_2.4.0            
##  [17] annotate_1.66.0             cluster_2.1.0              
##  [19] dbplyr_1.4.4                HiTC_1.32.0                
##  [21] png_0.1-7                   R.oo_1.24.0                
##  [23] compiler_4.0.2              httr_1.4.2                 
##  [25] backports_1.1.10            assertthat_0.2.1           
##  [27] Matrix_1.2-18               lazyeval_0.2.2             
##  [29] htmltools_0.5.0             prettyunits_1.1.1          
##  [31] tools_4.0.2                 igraph_1.2.5               
##  [33] gtable_0.3.0                glue_1.4.2                 
##  [35] GenomeInfoDbData_1.2.3      dplyr_1.0.2                
##  [37] rappdirs_0.3.1              Rcpp_1.0.5                 
##  [39] Biobase_2.48.0              vctrs_0.3.4                
##  [41] xfun_0.18                   stringr_1.4.0              
##  [43] lifecycle_0.2.0             ensembldb_2.12.1           
##  [45] XML_3.99-0.5                InteractionSet_1.16.0      
##  [47] zlibbioc_1.34.0             MASS_7.3-53                
##  [49] scales_1.1.1                VariantAnnotation_1.34.0   
##  [51] GenomicInteractions_1.22.0  hms_0.5.3                  
##  [53] ProtGenerics_1.20.0         SummarizedExperiment_1.18.2
##  [55] AnnotationFilter_1.12.0     RColorBrewer_1.1-2         
##  [57] yaml_2.2.1                  curl_4.3                   
##  [59] memoise_1.1.0               gridExtra_2.3              
##  [61] ggplot2_3.3.2               biomaRt_2.44.1             
##  [63] rpart_4.1-15                latticeExtra_0.6-29        
##  [65] stringi_1.5.3               RSQLite_2.2.1              
##  [67] genefilter_1.70.0           checkmate_2.0.0            
##  [69] GenomicFeatures_1.40.1      BiocParallel_1.22.0        
##  [71] rlang_0.4.7                 pkgconfig_2.0.3            
##  [73] matrixStats_0.57.0          bitops_1.0-6               
##  [75] evaluate_0.14               lattice_0.20-41            
##  [77] purrr_0.3.4                 labeling_0.3               
##  [79] GenomicAlignments_1.24.0    htmlwidgets_1.5.2          
##  [81] bit_4.0.4                   tidyselect_1.1.0           
##  [83] magrittr_1.5                DESeq2_1.28.1              
##  [85] R6_2.4.1                    generics_0.0.2             
##  [87] Hmisc_4.4-1                 DelayedArray_0.14.1        
##  [89] DBI_1.1.0                   pillar_1.4.6               
##  [91] foreign_0.8-80              survival_3.2-7             
##  [93] RCurl_1.98-1.2              nnet_7.3-14                
##  [95] tibble_3.0.3                crayon_1.3.4               
##  [97] BiocFileCache_1.12.1        rmarkdown_2.4              
##  [99] jpeg_0.1-8.1                progress_1.2.2             
## [101] locfit_1.5-9.4              grid_4.0.2                 
## [103] data.table_1.13.0           blob_1.2.1                 
## [105] digest_0.6.25               xtable_1.8-4               
## [107] tidyr_1.1.2                 R.utils_2.10.1             
## [109] openssl_1.4.3               munsell_0.5.0              
## [111] Gviz_1.32.0                 askpass_1.1


mervesa/HiCDCPlus documentation built on June 8, 2022, 3:43 a.m.