Seqanswers Leaderboard Ad

Collapse

Announcement

Collapse
No announcement yet.
X
 
  • Filter
  • Time
  • Show
Clear All
new posts

  • Problem with Newbler 2.6 with 454+Illumina data

    Hi,

    I try to use Newbler 2.6 to reconstruct eucaryote transcriptome from 454 + Illumina SE data (100pb).
    I made few test but it’s very long : 1 week for 500.000 reads 454 + 85 millions reads Illumina.

    I run this command line :
    /runAssembly -cdna -cpu 8 -mi 95 -ml 40 -urt fastq_file sff_file.

    I have many problems :
    1) Newbler recognize my fastq_file as a pairend fastq, while it is not the case. Anybody have a explanation?
    2) Why the job is so long?
    3) The parameter -ml 40 is it rigth? or I should try a other values?

    Thank in advance,

  • #2
    ml 40 is fine. 1 week isn't long considering you are using 85 million illumina reads! In the past I used 1.2 million gs flx reads and 2 millions 100bp se hiseq2000 reads for a eukaryote transcriptome. This completed in about 2 days on a desktop with a quad core i5 processor and 16gb of ram under newbler2.6. Do you really need to use all 85 million illumina reads? I suspect not

    In an earlier version of newbler i noticed a delay when trying to assemble data in different formats i.e. fasta+qual and sff was slower than assembly everything in fasta+qual format.

    Never used urt option so don't know if this increases time required

    Comment


    • #3
      try "-large" parameter for higher abundance data. It may speed up.



      Originally posted by markestine View Post
      Hi,

      I try to use Newbler 2.6 to reconstruct eucaryote transcriptome from 454 + Illumina SE data (100pb).
      I made few test but it’s very long : 1 week for 500.000 reads 454 + 85 millions reads Illumina.

      I run this command line :
      /runAssembly -cdna -cpu 8 -mi 95 -ml 40 -urt fastq_file sff_file.

      I have many problems :
      1) Newbler recognize my fastq_file as a pairend fastq, while it is not the case. Anybody have a explanation?
      2) Why the job is so long?
      3) The parameter -ml 40 is it rigth? or I should try a other values?

      Thank in advance,

      Comment


      • #4
        I think "-large" is not recommended (maybe not allowed?) for cDNA assemblies.

        Comment

        Latest Articles

        Collapse

        • seqadmin
          Essential Discoveries and Tools in Epitranscriptomics
          by seqadmin




          The field of epigenetics has traditionally concentrated more on DNA and how changes like methylation and phosphorylation of histones impact gene expression and regulation. However, our increased understanding of RNA modifications and their importance in cellular processes has led to a rise in epitranscriptomics research. “Epitranscriptomics brings together the concepts of epigenetics and gene expression,” explained Adrien Leger, PhD, Principal Research Scientist...
          04-22-2024, 07:01 AM
        • seqadmin
          Current Approaches to Protein Sequencing
          by seqadmin


          Proteins are often described as the workhorses of the cell, and identifying their sequences is key to understanding their role in biological processes and disease. Currently, the most common technique used to determine protein sequences is mass spectrometry. While still a valuable tool, mass spectrometry faces several limitations and requires a highly experienced scientist familiar with the equipment to operate it. Additionally, other proteomic methods, like affinity assays, are constrained...
          04-04-2024, 04:25 PM

        ad_right_rmr

        Collapse

        News

        Collapse

        Topics Statistics Last Post
        Started by seqadmin, Yesterday, 08:47 AM
        0 responses
        12 views
        0 likes
        Last Post seqadmin  
        Started by seqadmin, 04-11-2024, 12:08 PM
        0 responses
        60 views
        0 likes
        Last Post seqadmin  
        Started by seqadmin, 04-10-2024, 10:19 PM
        0 responses
        59 views
        0 likes
        Last Post seqadmin  
        Started by seqadmin, 04-10-2024, 09:21 AM
        0 responses
        54 views
        0 likes
        Last Post seqadmin  
        Working...
        X