Unconfigured Ad

Collapse
X
 
  • Time
  • Show
Clear All
new posts
  • yvan.wenger
    Member
    • Aug 2009
    • 30

    #1

    De-Novo transcriptome with 454 Titanium

    Hello everybody,

    Has somebody done transcriptome assemblies with 454 Titanium sequences?

    The goal of my experiment would be to assemble a comprehensive "transcriptome space" and not to do anything quantitative. Based on preliminary experiments, I expect roughly 15'000-20'000 different genes representing between 25x10⁶ and 50x10⁶ Mb refseq-like transcripts (including all possible exons in each reference sequence).

    I*would particularly be interested if someone could advise/speculate on one or several of these points:

    - PolyA enriched samples vs Normalized samples (loss of rare transcripts? efficiency?)

    - Paired end librairies (overlapping maybe? or particular insert sizes?) vs single end librairies

    - The quantity of reads (or plates assuming 1x10⁶ reads per plate) required to signal a good fraction of all the transcripts expressed (e.g 95-98%)

    - The "average" (for the whole sequencing)*or "minimum" (for rare transcripts) coverage required to obtain a good contiguity after de-novo assembly (e.g. 80%+ full length transcripts)

    - The incidence of the points mentioned above on the presence of rare transcripts such as transcription factors in the final assembly.

    Please don't hesitate to point to recent publications or other threads.

    Cheers,

    Yvan
  • krobison
    Senior Member
    • Nov 2007
    • 734

    #2
    If you search PubMed for "454 AND transcriptome" it gets quite a haul; have you found any of those papers useful or are they too dated (a general problem with this field; the technology evolves faster than people can push publications out!)

    Comment

    • yvan.wenger
      Member
      • Aug 2009
      • 30

      #3
      Yep, most of the publications are focused on "pre-titanium"
      technologies and de-novo transcriptome applications are not so
      common... But I bet that even if the scientific litterature is not so
      prolific at this time, many people are currently working on it.

      Comment

      • flxlex
        Moderator
        • Nov 2008
        • 412

        #4
        Being a bit focused on newbler, I would wait till the new release which includes a transcriptome module for assembly. It generates transcript variants (for example alternative splice variants) grouped according to gene.

        To be fair, there are certainly other programs out there that might do a good, or even better job, for example Abyss: http://www.ncbi.nlm.nih.gov/pubmed/19528083 for Illumina reads (perhaps this works also for 454 reads?).

        Comment

        Latest Articles

        Collapse

        • SEQadmin2
          Multiomic Liquid Biopsy: What DNA/RNA Panels Reveal That DNA Alone Can’t
          by SEQadmin2



          Tumors contain complex mixtures of cell populations that evolve in response to treatment and host-specific factors. Tissue biopsies provide only static snapshots of a tumor’s state. But what if we could follow that evolution over time using a minimally invasive technique?

          Liquid biopsies can detect tumor-derived material circulating in the bloodstream, providing a way to study treatment response, detect emerging resistance, and discover new biomarkers. Circulating
          ...
          10-14-2026, 09:55 AM
        • SEQadmin2
          New Genomics Technologies Take Aim at Long-Standing Limits
          by SEQadmin2


          Researchers using sequencing and genomics tools often have to make trade-offs. They can choose between speed or scale, short reads or long-range information, or targeted panels or a view of the whole transcriptome. New technologies that have been released this year are built to address those tough choices.

          We asked six companies the same four questions to learn about their latest products. The new technologies bring a lot to the table, including rethinking sequencing
          ...
          09-28-2026, 10:25 AM

        ad_right_rmr

        Collapse

        News

        Collapse

        Topics Statistics Last Post
        Started by SEQadmin2, 10-22-2026, 11:13 AM
        0 responses
        24 views
        0 reactions
        Last Post SEQadmin2  
        Started by SEQadmin2, 10-22-2026, 10:48 AM
        0 responses
        20 views
        0 reactions
        Last Post SEQadmin2  
        Started by SEQadmin2, 10-15-2026, 10:52 AM
        0 responses
        36 views
        0 reactions
        Last Post SEQadmin2  
        Started by SEQadmin2, 10-14-2026, 05:39 AM
        0 responses
        42 views
        0 reactions
        Last Post SEQadmin2  
        Working...