Unconfigured Ad

Collapse
X
 
  • Filter
  • Time
  • Show
Clear All
new posts
  • WhatsOEver
    Senior Member
    • Apr 2012
    • 215

    Looking for mapper that produces padded alignments

    Hi everyone,
    I'm looking for an RNAseq mapping tool (not a de novo assembler!) that is able to output padded alignments ('P' char in the cigar string) against a reference. I would be grateful for any suggestions!
    W
    Last edited by WhatsOEver; 07-22-2014, 06:40 AM. Reason: solved
  • dpryan
    Devon Ryan
    • Jul 2011
    • 3478

    #2
    I'd be a bit surprised if one exists. There's no reason to create one to produce padded alignments since padding has no biological meaning. Further, the padding can only be calculated after the mapping is complete, since it's for viewing multiple alignments.

    Comment

    • WhatsOEver
      Senior Member
      • Apr 2012
      • 215

      #3
      I know all this... still, I need this kind of alignment. It's just a question whether something like this already exists or I have to write it on my own.

      Comment

      • WhatsOEver
        Senior Member
        • Apr 2012
        • 215

        #4
        Maybe it's better to give the example from the sam spec to show what I mean:

        Code:
        Padded alignment.
        
        Most sequence aligners only give the sequences inserted to the reference genome, 
        but do not present how these inserted sequences are aligned against each other. 
        Alignment with inserted sequences fully aligned is
        called padded alignment. Padded alignment is always produced by
        de novo assemblers and is important for an alignment viewer to display the 
        alignment properly. To store padded alignment, we introduce operation ʻPʼ which 
        can be considered as a silent deletion from padded reference sequence. In the 
        following example, GA on READ1 and A on READ2 are inserted to the reference. 
        With unpadded CIGAR, we would not be able to distinguish the following padded 
        multi-alignments:
        
        [FONT="Courier New"]REF: CACGATCA**GACCGATACGTCCGA           REF: CACGATCA**GACCGATACGTCCGA
        READ1: CGATCAGAGACCGATA                  READ1: CGATCAGAGACCGATA
        READ2:   ATCA*AGACCGATAC                 READ2:   ATCAA*GACCGATAC
        READ3:  GATCA**GACCG                     READ3:  GATCA**GACCG
        
        The padded CIGAR are different:
        READ1: 6M2I8M                            READ1: 6M2I8M
        READ2: 4M1P1I9M                          READ2: 4M1I1P9M
        READ3: 5M2P5M                            READ3: 5M2P5M[/FONT]
        I need to work with the left one, not the right one. Are there any tools/libraries/whatever available to do it?

        Comment

        • maubp
          Peter (Biopython etc)
          • Jul 2009
          • 1544

          #5
          I'm not aware of a tool to do this... You might have to write a bit of code to post-process your traditional alignment output?
          Last edited by maubp; 07-22-2014, 04:22 AM. Reason: Typo

          Comment

          • WhatsOEver
            Senior Member
            • Apr 2012
            • 215

            #6
            I actually thought there should be something, as these kind of alignments are used in alignment viewers, aren't they?
            But there was indeed nothing I could use - I have now written my own code, yes.
            I would have closed the thread (or add a "solved" to the title or deleted everything), but that's not possible here, is it?

            Comment

            • maubp
              Peter (Biopython etc)
              • Jul 2009
              • 1544

              #7
              A few alignment views like 'samtools tview' and bambino can expand inserts, but most SAM/BAM viewers do not show the insert explicitly and ignore CIGAR P operators.

              You can edit the title via editing the original post, but this isn't really solved, is it?

              Comment

              • WhatsOEver
                Senior Member
                • Apr 2012
                • 215

                #8
                Originally posted by maubp View Post
                A few alignment views like 'samtools tview' and bambino can expand inserts, but most SAM/BAM viewers do not show the insert explicitly and ignore CIGAR P operators.
                I looked at bambino and tablet. Both are able to produce padded alignments. But you cannot export them (as no one seems to be interested in it).


                You can edit the title via editing the original post
                I always use quick editing were you can't edit the title. Have found it under advanced, thanks.

                but this isn't really solved, is it?
                Well, I couldn't find a tool, nobody could suggest one, I wrote one on my own which works nicely; so, now there is one, which I have. I consider this as solved

                Comment

                • Brian Bushnell
                  Super Moderator
                  • Jan 2014
                  • 2709

                  #9
                  It's not solved till you make the tool it publicly available

                  Comment

                  • Matt Kearse
                    Member
                    • Mar 2014
                    • 20

                    #10
                    I'm a little late to this discussion since you've written what you need already. But since your solution isn't publicly available yet I'll point out that Geneious (which is commercial software) has an iterative mapper which produces padded alignments. There is a short video demonstrating this at https://www.youtube.com/watch?v=IOGmxjK3f_4

                    Comment

                    • WhatsOEver
                      Senior Member
                      • Apr 2012
                      • 215

                      #11
                      @Brian: Good point, but so far its highly tailored to my specific needs. Once it is in a state were someone else can use it, I can make it public.

                      @Matt: Thanks for the info. I should have mentioned that it is (so far) not important enough to pay for it. I'm actually just testing if this is an improvement to my current project.

                      Comment

                      Latest Articles

                      Collapse

                      • mylaser
                        Reply to Advanced Sequencing Platforms Tackle Neuroscience’s Toughest Genomics Problems
                        by mylaser
                        Kheloyaar: The Complete Guide to Kheloyaar Loginand Kheloyaar ID
                        The online gaming industry has transformed the way people enjoy digital entertainment. As technology continues to improve, players are looking for platforms that offer convenience, security, and a seamless user experience. Kheloyaarhas gained attention among users who value an easy-to-use platform, quick account access, and a simple registration process.
                        Whether you're exploring Kheloyaar for the first time or want to understand...
                        Yesterday, 09:27 PM
                      • SEQadmin2
                        Advanced Sequencing Platforms Tackle Neuroscience’s Toughest Genomics Problems
                        by SEQadmin2



                        Genomics studies in neuroscience face a special challenge due to the brain’s complexity and scarcity of samples. Mapping changes in cell type and state using conventional next-generation sequencing methods remains challenging. Advances in technologies like single-cell sequencing, spatial transcriptomics, and long-read sequencing have opened the door to deeper studies of the brain and diseases like Alzheimer’s, amyotrophic lateral sclerosis (ALS), and schizophrenia.
                        ...
                        Yesterday, 11:10 AM
                      • SEQadmin2
                        Cancer Drug Resistance: The Lingering Barrier to Rising Survival
                        by SEQadmin2



                        Cancer survival rates have significantly increased in the last few decades in the United States, reaching a combined 70% 5-year survival rate by 2021. Behind this number, there are years of research to find new therapies, drug targets, and early detection methods. But there is one core challenge that keeps slowing down these advances, and it’s about drug resistance.

                        There is no single reason why many patients don’t respond to treatment as expected. Cancer is...
                        07-08-2026, 05:17 AM

                      ad_right_rmr

                      Collapse

                      News

                      Collapse

                      Topics Statistics Last Post
                      Started by SEQadmin2, Yesterday, 10:04 AM
                      0 responses
                      8 views
                      0 reactions
                      Last Post SEQadmin2  
                      Started by SEQadmin2, 07-08-2026, 10:08 AM
                      0 responses
                      7 views
                      0 reactions
                      Last Post SEQadmin2  
                      Started by SEQadmin2, 07-07-2026, 11:05 AM
                      0 responses
                      11 views
                      0 reactions
                      Last Post SEQadmin2  
                      Started by SEQadmin2, 07-02-2026, 11:08 AM
                      0 responses
                      31 views
                      0 reactions
                      Last Post SEQadmin2  
                      Working...