Extract multi exonic genes from gtf files

Question

[waqaskhokhar999]

I want to get count of multi-exonic genes from the stringtie assembled gtf file of Arabidopsis genome, For example, transcript ( transcript_id "MSTRG.1.2") of gene (gene_id "MSTRG.1") contains 6 exons (exon_number "1", exon_number "2", exon_number "3", exon_number "4", exon_number "5", exon_number "6") while transcript ( transcript_id "MSTRG.2.1") of gene (gene_id "MSTRG.2") contains 1 exon only (exon_number "1"). The output should be like this:

gene_id t_name  num_exons

MSTRG.1 MSTRG.1.2   6

MSTRG.1 MSTRG.1.3   5

MSTRG.2 MSTRG.2.1   1

I have checked this link, but in this link format of gtf file is different.

Sample input:

1   StringTie   transcript  3651    5899    1000    +   .   gene_id "MSTRG.1"; transcript_id "MSTRG.1.2"; 

1   StringTie   exon    3651    3913    1000    +   .   gene_id "MSTRG.1"; transcript_id "MSTRG.1.2"; exon_number "1"; 

1   StringTie   exon    3996    4276    1000    +   .   gene_id "MSTRG.1"; transcript_id "MSTRG.1.2"; exon_number "2"; 

1   StringTie   exon    4506    4605    1000    +   .   gene_id "MSTRG.1"; transcript_id "MSTRG.1.2"; exon_number "3"; 

1   StringTie   exon    4706    5095    1000    +   .   gene_id "MSTRG.1"; transcript_id "MSTRG.1.2"; exon_number "4"; 

1   StringTie   exon    5174    5326    1000    +   .   gene_id "MSTRG.1"; transcript_id "MSTRG.1.2"; exon_number "5"; 

1   StringTie   exon    5439    5899    1000    +   .   gene_id "MSTRG.1"; transcript_id "MSTRG.1.2"; exon_number "6"; 

1   StringTie   transcript  3657    5899    1000    +   .   gene_id "MSTRG.1"; transcript_id "MSTRG.1.3"; 

1   StringTie   exon    3657    3913    1000    +   .   gene_id "MSTRG.1"; transcript_id "MSTRG.1.3"; exon_number "1"; 

1   StringTie   exon    3996    4276    1000    +   .   gene_id "MSTRG.1"; transcript_id "MSTRG.1.3"; exon_number "2"; 

1   StringTie   exon    4486    5095    1000    +   .   gene_id "MSTRG.1"; transcript_id "MSTRG.1.3"; exon_number "3"; 

1   StringTie   exon    5174    5326    1000    +   .   gene_id "MSTRG.1"; transcript_id "MSTRG.1.3"; exon_number "4"; 

1   StringTie   exon    5439    5899    1000    +   .   gene_id "MSTRG.1"; transcript_id "MSTRG.1.3"; exon_number "5"; 

1   StringTie   transcript  15498   15756   1000    .   .   gene_id "MSTRG.2"; transcript_id "MSTRG.2.1"; 

1   StringTie   exon    15498   15756   1000    .   .   gene_id "MSTRG.2"; transcript_id "MSTRG.2.1"; exon_number "1"; 

1   StringTie   transcript  6788    11170   1000    -   .   gene_id "MSTRG.3"; transcript_id "MSTRG.3.1";

[Nicolas Rosewick]

your question is not clear. FYI most genes (in human) are multi-exonic.. Could you clarify your question please?

[ATpoint]

What you have to do is to isolate the gene_id and transcript_id part, e.g. using awk and then count e.g. using uniq -c. I strongly suggest you try to solve this yourself using google as this really improves an essential skill in bioinformatics => data sanitation.