Unconfigured Ad

Collapse
X
 
  • Filter
  • Time
  • Show
Clear All
new posts
  • AnamikaDarwin
    Member
    • Nov 2008
    • 26

    Maq Alignment Coordinates

    I have used maq to align a set of illumina reads to a reference assembly. Is there a way to directly get the alignment coordinates for the reference assembly?

    Thanks,
    Anamika

    PS, I had inadvertently posted the above question in a different section.
  • ECO
    --Site Admin--
    • Oct 2007
    • 1360

    #2
    Hey! I'm not at a computer so i cant verify, but I think it's maq mapview...

    Comment

    • apfejes
      Senior Member
      • Feb 2008
      • 236

      #3
      I believe ECO is right. It's "maq mapview filename.map" to display a binary .map file into a human readable format. I usually end up piping it to less so that it doesn't scroll by at unreadable speeds.

      Still, I have to wonder, ECO, If you're not at a computer, how did you post that? (-;
      The more you know, the more you know you don't know. —Aristotle

      Comment

      • ECO
        --Site Admin--
        • Oct 2007
        • 1360

        #4
        Originally posted by apfejes View Post
        I believe ECO is right. It's "maq mapview filename.map" to display a binary .map file into a human readable format. I usually end up piping it to less so that it doesn't scroll by at unreadable speeds.

        Still, I have to wonder, ECO, If you're not at a computer, how did you post that? (-;
        iPhone != computer in most senses...

        Comment

        • apfejes
          Senior Member
          • Feb 2008
          • 236

          #5
          Well, there go my theories of you being an AI or having a cybernetic implant...
          The more you know, the more you know you don't know. —Aristotle

          Comment

          • AnamikaDarwin
            Member
            • Nov 2008
            • 26

            #6
            maq mapview right solution

            Thanks Eco. Once I ran it with the -b option ( the read sequence and the quality are not displayed).

            From this output, I plan to get the coordinates of those regions that did not align (roughly about ~15% of the assembly.)

            Cheers,
            Anamika.

            Comment

            • ECO
              --Site Admin--
              • Oct 2007
              • 1360

              #7
              Good luck!

              Comment

              • zee
                NGS specialist
                • Apr 2008
                • 249

                #8
                Anamika,

                It would help if you checked the coverage of your reads on the assembly using maq.

                First assemble the reads into a consensus:

                0) merge all your reads into a single .map file
                1) maq assemble output.cns genome.bfa reads.map &> asm.log
                2) maq cns2win -w 10000 output.cns > windows.csv

                If you plot columns 6 & 7 you get an indication of read depth and coverage of your sequences against the genome.

                Hope this helps you out.

                Comment

                • AnamikaDarwin
                  Member
                  • Nov 2008
                  • 26

                  #9
                  Hi Zee,

                  I use the option you suggest to get the read depth for the SNP data. However, my aim is to get those coordinates of the assembly that did not align with my input reads. I have about ~15% not aligning.

                  Thanks,
                  Anamika

                  Comment

                  • xzk421
                    Junior Member
                    • Jan 2009
                    • 4

                    #10
                    maq

                    hello,
                    when using MAQ, after the command :
                    ./maq map 1131.map onecdna.bfa coli.bfa
                    the sreen print:
                    -- maq-0.7.1
                    [ma_load_reads] loading reads...
                    [ma_load_reads] set length of the first read as 35.
                    Segmentation fault


                    what the "Segmentation fault" mean?
                    provide my best services for you

                    Comment

                    • mosamam
                      Junior Member
                      • Jan 2009
                      • 1

                      #11
                      Originally posted by xzk421 View Post
                      hello,
                      when using MAQ, after the command :
                      ./maq map 1131.map onecdna.bfa coli.bfa
                      the sreen print:
                      -- maq-0.7.1
                      [ma_load_reads] loading reads...
                      [ma_load_reads] set length of the first read as 35.
                      Segmentation fault


                      what the "Segmentation fault" mean?

                      It means that you have not defined you data path

                      Comment

                      • kvarala
                        Junior Member
                        • Nov 2008
                        • 5

                        #12
                        Originally posted by zee View Post
                        Anamika,

                        It would help if you checked the coverage of your reads on the assembly using maq.

                        First assemble the reads into a consensus:

                        0) merge all your reads into a single .map file
                        1) maq assemble output.cns genome.bfa reads.map &> asm.log
                        2) maq cns2win -w 10000 output.cns > windows.csv

                        If you plot columns 6 & 7 you get an indication of read depth and coverage of your sequences against the genome.

                        Hope this helps you out.
                        The read depth in column 6 is easy enough to understand but what does the value in column 7 mean? My best guess is that it gives the average mapping quality for that region. Is that even close?

                        Comment

                        Latest Articles

                        Collapse

                        • SEQadmin2
                          Nine Things a Sample Prep Scientist Thinks About Before Sequencing
                          by SEQadmin2


                          I’m not a sequencing expert. I’m a purification scientist who uses NGS to evaluate workflows my group develops. With this perspective, we think about the sample first and the NGS workflow second. The sequencer is an exceptionally honest reporter, but it can only report on what you give it, so whether you get clean, interpretable data from an NGS workflow is largely determined before you begin.


                          Here are nine questions we think about, in roughly the order they matter, before...
                          06-18-2026, 07:11 AM
                        • SEQadmin2
                          From Collection to Sequencing: Why Sample Preparation and Preservation Define Sequencing Data
                          by SEQadmin2


                          Data variability is still an issue in sequencing technologies despite the advances in reproducibility and accuracy of these platforms. But the problem does not originate in the sequencing itself, but in the previous steps, before the sample reaches the sequencer.


                          The first step is collection, followed by preservation and sample preparation for analysis. Most scientists overlook those steps, but not being careful might just be skewing the experiment’s results.
                          ...
                          06-02-2026, 10:05 AM
                        • SEQadmin2
                          Single-Cell Sequencing at an Inflection Point: Early Impacts of New Platforms and Emerging Trends
                          by SEQadmin2


                          With the launch of new single-cell sequencing platforms in 2026, the field stands at an exciting inflection point. This article surveys the most impactful advances in the field and discusses how they’re reshaping research in cancer, immunology, and beyond.


                          Introduction

                          Single-cell sequencing technologies have undergone remarkable advances over the past decade, transitioning from low-throughput experimental approaches to highly scalable platforms capable of...
                          05-22-2026, 06:42 AM

                        ad_right_rmr

                        Collapse

                        News

                        Collapse

                        Topics Statistics Last Post
                        Started by SEQadmin2, 06-17-2026, 06:09 AM
                        0 responses
                        21 views
                        0 reactions
                        Last Post SEQadmin2  
                        Started by SEQadmin2, 06-09-2026, 11:58 AM
                        0 responses
                        38 views
                        0 reactions
                        Last Post SEQadmin2  
                        Started by SEQadmin2, 06-05-2026, 10:09 AM
                        0 responses
                        45 views
                        0 reactions
                        Last Post SEQadmin2  
                        Started by SEQadmin2, 06-04-2026, 08:59 AM
                        0 responses
                        49 views
                        0 reactions
                        Last Post SEQadmin2  
                        Working...