GSNAP and GFF

[markestine]

Hello,

I try to use GSNAP to map RNAseq on human genome.

I built the gmapdb and I created the file .iit whith the human_GFF:
#iit_store -G -l ID -o CHR37 HomoCH37.gff3

When I run GSNAP whith this command :
# gsnap -d CHR37 -m 6 --nofails -A sam -s CHR37 -N 1 -S 1 -B 4 -t 2
fastq_seq
I have this error message :
"Reading splicesite file
/usr/local/share/gmapdb/CHR37/CHR37.maps/CHR37...Splicesite file
CHR37.iit does not have tag 'donor'."

I don't understand why I have this message?
I would like used the GFF when I map the RNASeq reads on the human
genome to take into account the splicing.

Can you help me resolve this problem?

Thanks in advance,
markestine