Dear All, I would like to add some filtering steps in my RNA-Seq pipeline. To do so, I used the accepted.hits from TopHat and apply a filter using NGS: SAM Tools > Filter SAM and select reads with bitwise flag 0x0002. This does the job. However, I am unable to use cufflink after this step and got the following error message that seems to indicate that the file contains no header and is unsorted. Is there a workaround ? Thanks a lot
http://main.g2.bx.psu.edu/u/dputhier/h/srx011549
Error running cufflinks. return code = 1 cufflinks: /lib64/libz.so.1: no version information available (required by cufflinks) Command line: cufflinks -q --no-update-check -s 20 -I 300000 -F 0.100000 -j 0.150000 -p 8 -m 200 -g /galaxy/main_pool/pool5/files/003/858/dataset_3858145.dat /galaxy/main_pool/pool1/files/003/858/dataset_3858306.dat [bam_header_read] EOF marker is absent. [bam_header_read] invalid BAM binary header (this is not a BAM file). File /galaxy/main_pool/pool1/files/003/858/dataset_3858306.dat doesn't appear to be a valid BAM file, trying SAM... [14:11:28] Loading reference annotation. [14:11:28] Inspecting reads and determining fragment length distribution.
Error: this SAM file doesn't appear to be correctly sorted! current hit is at chr10:181061, last one was at chr1:245006405 Cufflinks requires that if your file has SQ records in the SAM header that they appear in the same order as the chromosomes names in the alignments. If there are no SQ records in the header, or if the header is missing, the alignments must be sorted lexicographically by chromsome name and by position.