| newcpgreport

## Function

Report CpG rich areas

## Description

This application is used in the production of the CpG Island database 'CPGISLE'. It produces CPGISLE database entry format reports for a potential CpG island.

See the FTP site: ftp://ftp.ebi.ac.uk/pub/databases/cpgisle/ for the finished database.

CpG refers to a C nucleotide immediately followed by a G. The 'p' in 'CpG' refers to the phosphate group linking the two bases.

Detection of regions of genomic sequences that are rich in the CpG pattern is important because such regions are resistant to methylation and tend to be associated with genes which are frequently switched on. Regions rich in the CpG pattern are known as CpG islands.

It has been estimated that about half of all mammalian genes have a CpG-rich region around their 5' end. It is said that all mammalian house-keeping genes have a CpG island!

Non-mammalian vertebrates have some CpG islands that are associated with genes, but the association gets equivocal in the farther taxonomic groups.

Finding a CpG island upstream of predicted exons or genes is good contributory evidence for that gene's existance.

By default, this program defines a CpG island as a region where, over an average of 10 windows, the calculated % composition is over 50% and the calculated Obs/Exp ratio is over 0.6 and the conditions hold for a minimum of 200 bases. These conditions can be modified by setting the values of the appropriate parameters.

The Expected number of CpG patterns in a window is calculated as the number of 'C's in the window multiplied by the number of 'G's in the window, divided by the window length.

This program reads in one or more sequences and finds regions where there is a high absolute frequency of CpG dimers as well as a high proportion of CpG compared to GpC.

## Usage

Here is a sample session with newcpgreport

    % newcpgreport
    Report CpG rich areas
    Input sequence(s): tembl:rnu68037
    Window size [100]:
    Shift increment [1]:
    Minimum Length [200]:
    Minimum observed/expected [0.6]:
    Minimum percentage [50.]:
    Output file [rnu68037.newcpgreport]:

Go to the input files for this example
Go to the output files for this example

## Command line arguments

       Mandatory qualifiers:
      [-sequence]          seqall     Sequence database USA
       -window             integer    Window size
       -shift              integer    Shift increment
       -minlen             integer    Minimum Length
       -minoe              float      Minimum observed/expected
       -minpc              float      Minimum percentage
      [-outfile]           outfile    Output file name

       Optional qualifiers: (none)
       Advanced qualifiers: (none)
       Associated qualifiers:
      "-sequence" related qualifiers
       -sbegin1             integer    First base used
       -send1               integer    Last base used, def=seq length
       -sreverse1           boolean    Reverse (if DNA)
       -sask1               boolean    Ask for begin/end/reverse
       -snucleotide1        boolean    Sequence is nucleotide
       -sprotein1           boolean    Sequence is protein
       -slower1             boolean    Make lower case
       -supper1             boolean    Make upper case
       -sformat1            string     Input sequence format
       -sopenfile1          string     Input filename
       -sdbname1            string     Database name
       -sid1                string     Entryname
       -ufo1                string     UFO features
       -fformat1            string     Features format
       -fopenfile1          string     Features file name
      "-outfile" related qualifiers
       -odirectory2         string     Output directory

       General qualifiers:
       -auto                boolean    Turn off prompts
       -stdout              boolean    Write standard output
       -filter              boolean    Read standard input, write standard output
       -options             boolean    Prompt for required and optional values
       -debug               boolean    Write debug output to program.dbg
       -acdlog              boolean    Write ACD processing log to program.acdlog
       -acdpretty           boolean    Rewrite ACD file as program.acdpretty
       -acdtable            boolean    Write HTML table of options
       -verbose             boolean    Report some/full command line options
       -help                boolean    Report command line options. More
                                      information on associated and general
                                      qualifiers can be found with -help -verbose
       -warning             boolean    Report warnings
       -error               boolean    Report errors
       -fatal               boolean    Report fatal errors
       -die                 boolean    Report deaths

Mandatory qualifiers | Allowed values | Default
--- | --- | ---
[-sequence] (Parameter 1) | Sequence database USA | Readable sequence(s) | Required
-window | Window size | Integer 1 or more | 100
-shift | Shift increment | Integer 1 or more | 1
-minlen | Minimum Length | Integer 1 or more | 200
-minoe | Minimum observed/expected | Number from 0.000 to 10.000 | 0.6
-minpc | Minimum percentage | Number from 0.000 to 100.000 | 50.
[-outfile] (Parameter 2) | Output file name | Output file | <sequence>.newcpgreport
Optional qualifiers | Allowed values | Default
(none)
Advanced qualifiers | Allowed values | Default
(none)

## Input file format

newcpgreport reads one or more nucleic acid sequences.

### Input files for usage example

'tembl:rnu68037' is a sequence entry in the example nucleic acid database 'tembl'

### Database entry: tembl:rnu68037

    ID   RNU68037   standard; RNA; ROD; 1218 BP.
    XX
    AC   U68037;
    XX
    SV   U68037.1
    XX
    DT   23-SEP-1996 (Rel. 49, Created)
    DT   04-MAR-2000 (Rel. 63, Last updated, Version 2)
    XX
    DE   Rattus norvegicus EP1 prostanoid receptor mRNA, complete cds.
    XX
    KW   .
    XX
    OS   Rattus norvegicus (Norway rat)
    OC   Eukaryota; Metazoa; Chordata; Craniata; Vertebrata; Euteleostomi; Mammalia;
    OC   Eutheria; Rodentia; Sciurognathi; Muridae; Murinae; Rattus.
    XX
    RN   [1]
    RP   1-1218
    RA   Abramovitz M., Boie Y.;
    RT   "Cloning of the rat EP1 prostanoid receptor";
    RL   Unpublished.
    XX
    RN   [2]
    RP   1-1218
    RA   Abramovitz M., Boie Y.;
    RT   ;
    RL   Submitted (26-AUG-1996) to the EMBL/GenBank/DDBJ databases.
    RL   Biochemistry & Molecular Biology, Merck Frosst Center for Therapeutic
    RL   Research, P. O. Box 1005, Pointe Claire - Dorval, Quebec H9R 4P8, Canada
    XX
    DR   SWISS-PROT; P70597; PE21_RAT.
    XX
    FH   Key             Location/Qualifiers
    FH
    FT   source          1..1218
    FT                   /db_xref="taxon:10116"
    FT                   /organism="Rattus norvegicus"
    FT                   /strain="Sprague-Dawley"
    FT   CDS             1..1218
    FT                   /codon_start=1
    FT                   /db_xref="SWISS-PROT:P70597"
    FT                   /note="family 1 G-protein coupled receptor"
    FT                   /product="EP1 prostanoid receptor"
    FT                   /protein_id="AAB07735.1"
    FT                   /translation="MSPYGLNLSLVDEATTCVTPRVPNTSVVLPTGGNGTSPALPIFSM
    FT                   TLGAVSNVLALALLAQVAGRLRRRRSTATFLLFVASLLAIDLAGHVIPGALVLRLYTAG
    FT                   RAPAGGACHFLGGCMVFFGLCPLLLGCGMAVERCVGVTQPLIHAARVSVARARLALALL
    FT                   AAMALAVALLPLVHVGHYELQYPGTWCFISLGPPGGWRQALLAGLFAGLGLAALLAALV
    FT                   CNTLSGLALLRARWRRRRSRRFRENAGPDDRRRWGSRGLRLASASSASSITSTTAALRS
    FT                   SRGGGSARRVHAHDVEMVGQLVGIMVVSCICWSPLLVLVVLAIGGWNSNSLQRPLFLAV
    FT                   RLASWNQILDPWVYILLRQAMLRQLLRLLPLRVSAKGGPTELSLTKSAWEASSLRSSRH
    FT                   SGFSHL"
    XX
    SQ   Sequence 1218 BP; 162 A; 397 C; 387 G; 272 T; 0 other;
         atgagcccct acgggcttaa cctgagccta gtggatgagg caacaacgtg tgtaacaccc        60
         agggtcccca atacatctgt ggtgctgcca acaggcggta acggcacatc accagcgctg       120
         cctatcttct ccatgacgct gggtgctgtg tccaacgtgc tggcgctggc gctgctggcc       180
         caggttgcag gcagactgcg gcgccgccgc tcgactgcca ccttcctgtt gttcgtcgcc       240
         agcctgcttg ccatcgacct agcaggccat gtgatcccgg gcgccttggt gcttcgcctg       300
         tatactgcag gacgtgcgcc cgctggcggg gcctgtcatt tcctgggcgg ctgtatggtc       360
         ttctttggcc tgtgcccact tttgcttggc tgtggcatgg ccgtggagcg ctgcgtgggt       420
         gtcacgcagc cgctgatcca cgcggcgcgc gtgtccgtag cccgcgcacg cctggcacta       480
         gccctgctgg ccgccatggc tttggcagtg gcgctgctgc cactagtgca cgtgggtcac       540
         tacgagctac agtaccctgg cacttggtgt ttcattagcc ttgggcctcc tggaggttgg       600
         cgccaggcgt tgcttgcggg cctcttcgcc ggccttggcc tggctgcgct ccttgccgca       660
         ctagtgtgta atacgctcag cggcctggcg ctccttcgtg cccgctggag gcggcgtcgc       720
         tctcgacgtt tccgagagaa cgcaggtccc gatgatcgcc ggcgctgggg gtcccgtgga       780
         ctccgcttgg cctccgcctc gtctgcgtca tccatcactt caaccacagc tgccctccgc       840
         agctctcggg gaggcggctc cgcgcgcagg gttcacgcac acgacgtgga aatggtgggc       900
         cagctcgtgg gcatcatggt ggtgtcgtgc atctgctgga gccccctgct ggtattggtg       960
         gtgttggcca tcgggggctg gaactctaac tccctgcagc ggccgctctt tctggctgta      1020
         cgcctcgcgt cgtggaacca gatcctggac ccatgggtgt acatcctgct gcgccaggct      1080
         atgctgcgcc aacttcttcg cctcctaccc ctgagggtta gtgccaaggg tggtccaacg      1140
         gagctgagcc taaccaagag tgcctgggag gccagttcac tgcgtagctc ccggcacagt      1200
         ggcttcagcc acttgtga                                                    1218
    //

## Output file format

### Output files for usage example

### File: rnu68037.newcpgreport

    ID   RNU68037  1218 BP.
    XX
    DE   CpG Island report.
    XX
    CC   Obs/Exp ratio > 0.60.
    CC   % C + % G > 50.00.
    CC   Length > 200.
    XX
    FH   Key              Location/Qualifiers
    FT   CpG island       104..509
    FT                    /size=406
    FT                    /Sum C+G=269
    FT                    /Percent CG=66.26
    FT                    /ObsExp=0.81
    FT   CpG island       596..924
    FT                    /size=329
    FT                    /Sum C+G=223
    FT                    /Percent CG=67.78
    FT                    /ObsExp=1.01
    FT   numislands       2
    //

## Data files

None.

## Notes

None.

## References

1. Larsen F., Gundersen, G., Lopez L., Prydz H. "CpG island as Gene Markers in the Human Genome" Genomics 13:1095-1107 (1992)

## Warnings

None.

## Diagnostic Error Messages

None.

## Exit status

It always exits with a status of 0.

## Known bugs

None.

## See also

Program name | Description
--- | ---
cpgplot | Plot CpG rich areas
cpgreport | Reports all CpG rich regions
geecee | Calculates the fractional GC content of nucleic acid sequences
newcpgseek | Reports CpG rich regions

As there is no official definition of what is a cpg island is, and worst where they begin and end, we have to live with 2 definitions and thus two methods. These are:

1. newcpgseek and cpgreport - both declare a putative island if the score is higher than a threshold (17 at the moment). They now also displaying the actual CpG count, the % CG and the observed/expected ration in the region where the score is above the threshold. This scoring method based on sum/frequencies overpredicts islands but finds the smaller ones around primary exons. newcpgseek uses the same method as cpgreport but the output is different and more readable.

2. newcpgreport and cpgplot use the method which mentioned in the Description section above. The important thing to note in this method is that an island, in order to be reported, is defined as a region that satisfies the following contraints:

       Obs/Exp ratio > 0.6
       % C + % G > 50%
       Length > 200.

For all practical purposes you should probably use newcpgreport. It is actually used to produce the human cpgisland database you can find on the EBI's ftp server as well as on the EBI's SRS server.

geecee measures CG content in the entire input sequence and is not to be used to detect CpG islands. It can be usefull for detecting sequences that MIGHT contain an island.

## Author(s)

Rodrigo Lopez (rls © ebi.ac.uk)
European Bioinformatics Institute, Wellcome Trust Genome Campus, Hinxton, Cambridge CB10 1SD, UK

## History

Written (1999) - Rodrigo Lopez.

## Target users

This program is intended to be used by everyone and everything, from naive users to embedded scripts.

## Comments