ChIP Analysis


macs2 [-h] [--version] {callpeak,filterdup,bdgpeakcall,bdgcmp,randsample,bdgdiff,bdgbroadcall}


-t/--treatment FILENAME
This is the only REQUIRED parameter for MACS. File can be in any supported format specified by --format option. Check --format for detail. If you have more than one alignment files, you can specify them as `-t A B C`. MACS will pool up all these files together.
The control or mock data file. Please follow the same direction as for -t/--treatment.
The name string of the experiment. MACS will use this string NAME to create output files like 'NAME_peaks.xls', 'NAME_negative_peaks.xls', 'NAME_peaks.bed' , 'NAME_summits.bed', 'NAME_model.r' and so on. So please avoid any confliction between these filenames and your existing files.
MACS2 will save all output files into speficied folder for this option.
-f/--format FORMAT
Format of tag file, can be "ELAND", "BED", "ELANDMULTI", "ELANDEXPORT", "ELANDMULTIPET" (for pair-end tags), "SAM", "BAM", "BOWTIE", "BAMPE" or "BEDPE". Default is "AUTO" which will allow MACS to decide the format automatically. "AUTO" is also usefule when you combine different formats of files. Note that MACS can't detect "BAMPE" or "BEDPE" format with "AUTO", and you have to implicitly specify the format for "BAMPE" and "BEDPE".
PLEASE assign this parameter to fit your needs!
The size of sequencing tags. If you don't specify it, MACS will try to use the first 10 sequences from your input treatment file to determine the tag size. Specifying it will override the automatically determined tag size.
The band width which is used to scan the genome ONLY for model building. You can set this parameter as the sonication fragment size expected from wet experiment. The previous side effect on the peak detection process has been removed. So this parameter only affects the model building.
The qvalue (minimum FDR) cutoff to call significant regions. Default is 0.01. For broad marks, you can try 0.05 as cutoff. Q-values are calculated from p-values using Benjamini-Hochberg procedure.
The pvalue cutoff. If -p is specified, MACS2 will use pvalue instead of qvalue.
This parameter is used to select the regions within MFOLD range of high-confidence enrichment ratio against background to build model. The regions must be lower than upper limit, and higher than the lower limit of fold enrichment. DEFAULT:5,50 means using all regions not too low (>5) and not too high (<50) to build paired-peaks model. If MACS can not find more than 100 regions to build model, it will use the --extsize parameter to continue the peak detection ONLY if --fix-bimodal is set.
With this flag on, MACS will use the background lambda as local lambda. This means MACS will not consider the local bias at peak candidate regions.
--slocal, --llocal
These two parameters control which two levels of regions will be checked around the peak regions to calculate the maximum lambda as local lambda. By default, MACS considers 1000bp for small local region(--slocal), and 10000bps for large local region(--llocal) which captures the bias from a long range effect like an open chromatin domain. You can tweak these according to your project. Remember that if the region is set too small, a sharp spike in the input data may kill the significant peak.
Whether turn on the auto paired-peak model process. If it's set, when MACS failed to build paired model, it will use the nomodel settings, the '--extsize' parameter to extend each tags. If set, MACS will be terminated if paried-peak model is failed.
While on, MACS will bypass building the shifting model.
While '--nomodel' is set, MACS uses this parameter to extend reads in 5'->3' direction to fix-sized fragments. For example, if the size of binding region for your transcription factor is 200 bp, and you want to bypass the model building by MACS, this parameter can be set as 200. This option is only valid when --nomodel is set or when MACS fails to build model and --fix-bimodal is on.
Note, this is NOT the legacy --shiftsize option which is replaced by --extsize! You can set an arbitrary shift in bp here. Please Use discretion while setting it other than default value (0). When --nomodel is set, MACS will use this value to move cutting ends (5') then apply --extsize from 5' to 3' direction to extend them to fragments. When this value is negative, ends will be moved toward 3'->5' direction, otherwise 5'->3' direction. Recommended to keep it as default 0 for ChIP-Seq datasets, or -1 * half of EXTSIZE together with --extsize option for detecting enriched cutting loci such as certain DNAseI-Seq datasets. Note, you can't set values other than 0 if format is BAMPE or BEDPE for paired-end data. Default is 0.
It controls the MACS behavior towards duplicate tags at the exact same location -- the same coordination and the same strand. The default 'auto' option makes MACS calculate the maximum tags at the exact same location based on binomal distribution using 1e-5 as pvalue cutoff; and the 'all' option keeps every tags. If an integer is given, at most this number of tags will be kept at the same location. The default is to keep one tag at the same location. Default: 1
When this flag is on, MACS will try to composite broad regions in BED12 ( a gene-model-like format ) by putting nearby highly enriched regions into a broad region with loose cutoff. The broad region is controlled by another cutoff through --broad-cutoff. The maximum length of broad region length is 4 times of d from MACS. DEFAULT: False
Cutoff for broad region. This option is not available unless --broad is set. If -p is set, this is a pvalue cutoff, otherwise, it's a qvalue cutoff. DEFAULT: 0.1
When set, linearly scale the smaller dataset to the same depth as larger dataset, by default, the larger dataset will be scaled towards the smaller dataset. Beware, to scale up small data would cause more false positives.
When set, random sampling method will scale down the bigger sample. By default, MACS uses linear scaling. This option will make the results unstable and irreproducible since each time, random reads would be selected, especially the numbers (pileup, pvalue, qvalue) would change. Consider to use 'randsample' script before MACS2 runs instead.
If this flag is on, MACS will store the fragment pileup, control lambda, -log10pvalue and -log10qvalue scores in bedGraph files. The bedGraph files will be stored in current directory named NAME+'_treat_pileup.bdg' for treatment data, NAME+'_control_lambda.bdg' for local lambda values from control, NAME+'_treat_pvalue.bdg' for Poisson pvalue scores (in -log10(pvalue) form), and NAME+'_treat_qvalue.bdg' for q-value scores from Benjamini–Hochberg–Yekutieli procedure
MACS will now reanalyze the shape of signal profile (p or q-score depending on cutoff setting) to deconvolve subpeaks within each peak called from general procedure. It's highly recommended to detect adjacent binding events. While used, the output subpeaks of a big peak region will have the same peak boundaries, and different scores and peak summit positions.
If you don't want to see any message during the running of MACS, set it to 0. But the CRITICAL messages will never be hidden. If you want to see rich information like how many peaks are called for every chromosome, you can set it to 3 or larger than 3.

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