Hello everybody,

I was trying to create a TxDb from a custom gtf for some analyses.
I found out that makeTranscriptDbFromGFF was replaced for the newer makeTxDbFromGFF, so I decided to try this function. To my surprise I got no error with the following code (see below), but when I inspected the TxDb (I saved it to a .sqlite file) It was almost empty (had only the "chrominfo" and "metadata" tables populated) so it was useless to generate a table of counts for example...

Here is an my code and the progress read on R-studio:

>library(GenomicFeatures)
> txdb <- makeTxDbFromGFF(file ="Custom_organism.gtf",
+                                 format="gtf",
+                                 exonRankAttributeName=NA,
+                                 dataSource="gtf file for C.organism",
+                                 organism="Custom_organism",
+                                  )
Import genomic features from the file as a GRanges object ... OK
Prepare the 'metadata' data frame ... OK
Make the TxDb object ... OK
Warning message:
In .extract_transcripts_from_GRanges(tx_IDX, gr, type, ID, Name) :
  The following transcripts have multiple parts that were merged:
> #save into transcript sqlite database
> if(interactive()) {
+   saveDb(txdb,file="Custom_organism.sqlite")
+ }
TxDb object:
# Db type: TxDb
# Supporting package: GenomicFeatures
# Data source: gtf file for C.organism
# Organism: Custom Organism
# Taxonomy ID: 138
# miRBase build ID: NA
# Genome: NA
# transcript_nrow: 0
# exon_nrow: 0
# cds_nrow: 0
# Db created by: GenomicFeatures package from Bioconductor
# Creation time: 2015-10-29 16:45:30 +0100 (Thu, 29 Oct 2015)
# GenomicFeatures version at creation time: 1.22.0
# RSQLite version at creation time: 1.0.0
# DBSCHEMAVERSION: 1.1

I blelieve the custom gtf file has an unusual format. It has an "mRNA" tag where "exon" or "CDS" tag usually appear and I can't figure out how to fit that into the makeTxDbFromGFF function call:

Contig130    unknown    mRNA    1    636    .    .    .    gene_id "Contig130";  description "gi|1234567| Custom organism polyprotein , putative, mRNA";  gene_symbol "NA";  mapping_type "transcriptome";

Can anybody help me to figure out how to accurately call makeTxDbFromGFF to obtain a TxDb from such a gtf? Any suggestion on how to modify this custom gtf to retrieve infotmation for the TxDb?

Thanks in advance,

Best wishes

JL

> sessionInfo()
R version 3.2.2 (2015-08-14)
Platform: x86_64-w64-mingw32/x64 (64-bit)
Running under: Windows 7 x64 (build 7601) Service Pack 1

locale:
[1] LC_COLLATE=Spanish_Spain.1252  LC_CTYPE=Spanish_Spain.1252   
[3] LC_MONETARY=Spanish_Spain.1252 LC_NUMERIC=C                  
[5] LC_TIME=Spanish_Spain.1252    

attached base packages:
[1] parallel  stats4    stats     graphics  grDevices utils     datasets  methods  
[9] base     

other attached packages:
 [1] GenomicFeatures_1.22.0     pheatmap_1.0.7             ggplot2_1.0.1             
 [4] org.Mm.eg.db_3.2.3         RSQLite_1.0.0              DBI_0.3.1                 
 [7] AnnotationDbi_1.32.0       calibrate_1.7.2            MASS_7.3-44               
[10] genefilter_1.52.0          gplots_2.17.0              RColorBrewer_1.1-2        
[13] DESeq2_1.10.0              RcppArmadillo_0.6.100.0.0  Rcpp_0.12.1               
[16] SummarizedExperiment_1.0.0 Biobase_2.30.0             GenomicRanges_1.22.0      
[19] GenomeInfoDb_1.6.0         IRanges_2.4.1              S4Vectors_0.8.0           
[22] BiocGenerics_0.16.0       

loaded via a namespace (and not attached):
 [1] locfit_1.5-9.1          lattice_0.20-33         Rsamtools_1.22.0       
 [4] Biostrings_2.38.0       gtools_3.5.0            digest_0.6.8           
 [7] plyr_1.8.3              futile.options_1.0.0    acepack_1.3-3.3        
[10] zlibbioc_1.16.0         annotate_1.48.0         gdata_2.17.0           
[13] rpart_4.1-10            proto_0.3-10            labeling_0.3           
[16] splines_3.2.2           BiocParallel_1.4.0      geneplotter_1.48.0     
[19] stringr_1.0.0           foreign_0.8-66          RCurl_1.95-4.7         
[22] biomaRt_2.26.0          munsell_0.4.2           rtracklayer_1.30.1     
[25] nnet_7.3-11             gridExtra_2.0.0         Hmisc_3.17-0           
[28] XML_3.98-1.3            GenomicAlignments_1.6.1 bitops_1.0-6           
[31] grid_3.2.2              xtable_1.7-4            gtable_0.1.2           
[34] magrittr_1.5            scales_0.3.0            KernSmooth_2.23-15     
[37] stringi_1.0-1           XVector_0.10.0          reshape2_1.4.1         
[40] latticeExtra_0.6-26     futile.logger_1.4.1     Formula_1.2-1          
[43] lambda.r_1.1.7          tools_3.2.2             survival_2.38-3        
[46] colorspace_1.2-6        cluster_2.0.3           caTools_1.17.1