Hello:
let me start by saying that I am very impressed by the service the  
Galaxy web server provides to the community; it has proven very useful  
for my work.
Today I came across a situation that puzzles me. I am trying to merge  
exons corresponding to the same gene (but possibly from different  
splice variants).
At the bottom of this email I am listing, as an example, the 153 exons  
that are related to the different splice variants of FlyBase gene  
CG32491 (obtained by the pattern matching (tool "Select lines that  
match an expression"  and pattern .+CG32491-. ) applied to the data  
set of FlyBaseGene exons (110,472 exons, genome assembly dm3). I am  
using bed format and the general Galaxy web server.
If I now apply the "Merge"  tool to the intervals, I obtain 26  
intervals (listed further below). Now applying the "subtract" tool to  
the original 153 exons results in 8 "leftover" regions that I did not  
expect. Somehow they seem to be missing in the merge result.
I then deactivated the strand information in the interval set of 153  
exons. Applying the merge tool now results in 34 intervals (again  
listed below). Checking the result via the subtract tool (subtracting  
the merge result from the original data set of 153 exons) results, as  
expected, in zero intervals.
So my questions are:
- is this the intended functionality of the tools? Maybe one can add  
statements regarding these issues in the tool documentation.
- why does the outcome of the merge operation depend on whether the  
"strand" column is set or not? The original set of intervals all had  
the same negative strand orientation, so it appears to me that the  
merge operation should give the same result in both cases.
- subtracting the merged intervals (that do not have strand  
information) from the set of 153 intervals results in 8 strands that  
now have positive strand orientation (they originally had negative  
strand orientation).  Why does subtracting a set of intervals without  
strand information from a set of intervals with strand information  
change the strand orientation of the first set?
Any comments are highly appreciated!
Thanks,
Eckart
Dr. Eckart Bindewald (Contractor)
SAIC-Frederick, Inc.
Center for Cancer Research Nanobiology Program
National Cancer Institute
P.O. Box B
Frederick, MD 21702 USA
Phone: 301-846-5538
Fax: 301-846-5598
E-mail: eckart(a)mail.nih.gov
Here is the result (34 regions) of the merge operation (not using  
strand orientation) applied to the 153 exon regions listed further  
below ;
chr3R	17177330	17177608
chr3R	17177760	17178959
chr3R	17179070	17179456
chr3R	17179617	17180053
chr3R	17180159	17180416
chr3R	17180695	17181279
chr3R	17181479	17181973
chr3R	17182071	17182426
chr3R	17182532	17182690
chr3R	17182776	17183086
chr3R	17183242	17183480
chr3R	17183726	17183926
chr3R	17184011	17184791
chr3R	17186111	17186276
chr3R	17186349	17187009
chr3R	17187119	17187332
chr3R	17187391	17187860
chr3R	17187909	17188590
chr3R	17188688	17189606
chr3R	17189739	17190097
chr3R	17190173	17190367
chr3R	17190435	17190714
chr3R	17191725	17192060
chr3R	17192171	17192466
chr3R	17193631	17193960
chr3R	17194101	17194784
chr3R	17195183	17196364
chr3R	17196654	17196949
chr3R	17197044	17197789
chr3R	17197884	17198802
chr3R	17200781	17201634
chr3R	17202323	17202463
chr3R	17202540	17202798
chr3R	17203009	17203121
Here is the result (26 regions) of the merge operation (using strand  
orientation) applied to the 153 exon regions listed further below ;
chr3R	17177330	17177608
chr3R	17177760	17178959
chr3R	17179070	17179456
chr3R	17179617	17180053
chr3R	17180159	17180416
chr3R	17180695	17181279
chr3R	17181479	17181973
chr3R	17182071	17182426
chr3R	17182532	17182690
chr3R	17182776	17183086
chr3R	17183242	17183480
chr3R	17183726	17183926
chr3R	17184011	17184791
chr3R	17187909	17188590
chr3R	17188688	17189606
chr3R	17189739	17190097
chr3R	17190173	17190367
chr3R	17190435	17190714
chr3R	17195821	17196364
chr3R	17196654	17196949
chr3R	17197044	17197789
chr3R	17197884	17198802
chr3R	17200781	17201634
chr3R	17202323	17202463
chr3R	17202540	17202798
chr3R	17203009	17203121
Here are the 8 "leftover" regions from the original 153 exons that do  
not intersect with the result of the 26 merged regions (result of  
subtract tool of 153 exons that do not overlap with 26 merged exons;  
note the change strand orientation):
chr3R	17186111	17186276	CG32491-RT_exon_0_0_chr3R_17186112_f	0	+
chr3R	17186349	17187009	CG32491-RT_exon_1_0_chr3R_17186350_f	0	+
chr3R	17187119	17187332	CG32491-RZ_exon_0_0_chr3R_17187120_f	0	+
chr3R	17187391	17187860	CG32491-RZ_exon_1_0_chr3R_17187392_f	0	+
chr3R	17191725	17192060	CG32491-RY_exon_0_0_chr3R_17191726_f	0	+
chr3R	17192171	17192466	CG32491-RX_exon_0_0_chr3R_17192172_f	0	+
chr3R	17193631	17193960	CG32491-RW_exon_0_0_chr3R_17193632_f	0	+
chr3R	17194101	17194784	CG32491-RV_exon_0_0_chr3R_17194102_f	0	+
Here are the 153 exons related to FlyBase gene CG32491 obtained by the  
pattern matching (tool "Select lines that match an expression"  and  
pattern .+CG32491-. ) applied to the data set of FlyBaseGene exons  
(110,472 exons):
chr3R	17177330	17177608	CG32491-RR_exon_0_0_chr3R_17177331_r	0	-
chr3R	17200781	17201634	CG32491-RR_exon_1_0_chr3R_17200782_r	0	-
chr3R	17202323	17202463	CG32491-RR_exon_2_0_chr3R_17202324_r	0	-
chr3R	17202540	17202798	CG32491-RR_exon_3_0_chr3R_17202541_r	0	-
chr3R	17203009	17203121	CG32491-RR_exon_4_0_chr3R_17203010_r	0	-
chr3R	17177760	17178358	CG32491-RA_exon_0_0_chr3R_17177761_r	0	-
chr3R	17200781	17201634	CG32491-RA_exon_1_0_chr3R_17200782_r	0	-
chr3R	17202323	17202463	CG32491-RA_exon_2_0_chr3R_17202324_r	0	-
chr3R	17202540	17202798	CG32491-RA_exon_3_0_chr3R_17202541_r	0	-
chr3R	17203009	17203121	CG32491-RA_exon_4_0_chr3R_17203010_r	0	-
chr3R	17178092	17178959	CG32491-RF_exon_0_0_chr3R_17178093_r	0	-
chr3R	17200781	17201634	CG32491-RF_exon_1_0_chr3R_17200782_r	0	-
chr3R	17202323	17202463	CG32491-RF_exon_2_0_chr3R_17202324_r	0	-
chr3R	17202540	17202798	CG32491-RF_exon_3_0_chr3R_17202541_r	0	-
chr3R	17203009	17203121	CG32491-RF_exon_4_0_chr3R_17203010_r	0	-
chr3R	17179070	17179456	CG32491-RD_exon_0_0_chr3R_17179071_r	0	-
chr3R	17200781	17201634	CG32491-RD_exon_1_0_chr3R_17200782_r	0	-
chr3R	17202323	17202463	CG32491-RD_exon_2_0_chr3R_17202324_r	0	-
chr3R	17202540	17202798	CG32491-RD_exon_3_0_chr3R_17202541_r	0	-
chr3R	17203009	17203121	CG32491-RD_exon_4_0_chr3R_17203010_r	0	-
chr3R	17179617	17180053	CG32491-RAC_exon_0_0_chr3R_17179618_r	0	-
chr3R	17200781	17201634	CG32491-RAC_exon_1_0_chr3R_17200782_r	0	-
chr3R	17202323	17202463	CG32491-RAC_exon_2_0_chr3R_17202324_r	0	-
chr3R	17202540	17202798	CG32491-RAC_exon_3_0_chr3R_17202541_r	0	-
chr3R	17203009	17203121	CG32491-RAC_exon_4_0_chr3R_17203010_r	0	-
chr3R	17180159	17180416	CG32491-RG_exon_0_0_chr3R_17180160_r	0	-
chr3R	17180695	17180811	CG32491-RG_exon_1_0_chr3R_17180696_r	0	-
chr3R	17200781	17201634	CG32491-RG_exon_2_0_chr3R_17200782_r	0	-
chr3R	17202323	17202463	CG32491-RG_exon_3_0_chr3R_17202324_r	0	-
chr3R	17202540	17202798	CG32491-RG_exon_4_0_chr3R_17202541_r	0	-
chr3R	17203009	17203121	CG32491-RG_exon_5_0_chr3R_17203010_r	0	-
chr3R	17180159	17180416	CG32491-RH_exon_0_0_chr3R_17180160_r	0	-
chr3R	17180695	17181279	CG32491-RH_exon_1_0_chr3R_17180696_r	0	-
chr3R	17200781	17201634	CG32491-RH_exon_2_0_chr3R_17200782_r	0	-
chr3R	17202323	17202463	CG32491-RH_exon_3_0_chr3R_17202324_r	0	-
chr3R	17202540	17202798	CG32491-RH_exon_4_0_chr3R_17202541_r	0	-
chr3R	17203009	17203121	CG32491-RH_exon_5_0_chr3R_17203010_r	0	-
chr3R	17180159	17180416	CG32491-RQ_exon_0_0_chr3R_17180160_r	0	-
chr3R	17200781	17201634	CG32491-RQ_exon_1_0_chr3R_17200782_r	0	-
chr3R	17202323	17202463	CG32491-RQ_exon_2_0_chr3R_17202324_r	0	-
chr3R	17202540	17202798	CG32491-RQ_exon_3_0_chr3R_17202541_r	0	-
chr3R	17203009	17203121	CG32491-RQ_exon_4_0_chr3R_17203010_r	0	-
chr3R	17180941	17181279	CG32491-RB_exon_0_0_chr3R_17180942_r	0	-
chr3R	17181479	17181973	CG32491-RB_exon_1_0_chr3R_17181480_r	0	-
chr3R	17200781	17201634	CG32491-RB_exon_2_0_chr3R_17200782_r	0	-
chr3R	17202323	17202463	CG32491-RB_exon_3_0_chr3R_17202324_r	0	-
chr3R	17202540	17202798	CG32491-RB_exon_4_0_chr3R_17202541_r	0	-
chr3R	17203009	17203121	CG32491-RB_exon_5_0_chr3R_17203010_r	0	-
chr3R	17182071	17182426	CG32491-RI_exon_0_0_chr3R_17182072_r	0	-
chr3R	17182532	17182690	CG32491-RI_exon_1_0_chr3R_17182533_r	0	-
chr3R	17200781	17201634	CG32491-RI_exon_2_0_chr3R_17200782_r	0	-
chr3R	17202323	17202463	CG32491-RI_exon_3_0_chr3R_17202324_r	0	-
chr3R	17202540	17202798	CG32491-RI_exon_4_0_chr3R_17202541_r	0	-
chr3R	17203009	17203121	CG32491-RI_exon_5_0_chr3R_17203010_r	0	-
chr3R	17182776	17183086	CG32491-RJ_exon_0_0_chr3R_17182777_r	0	-
chr3R	17200781	17201634	CG32491-RJ_exon_1_0_chr3R_17200782_r	0	-
chr3R	17202323	17202463	CG32491-RJ_exon_2_0_chr3R_17202324_r	0	-
chr3R	17202540	17202798	CG32491-RJ_exon_3_0_chr3R_17202541_r	0	-
chr3R	17203009	17203121	CG32491-RJ_exon_4_0_chr3R_17203010_r	0	-
chr3R	17183242	17183480	CG32491-RP_exon_0_0_chr3R_17183243_r	0	-
chr3R	17183726	17183926	CG32491-RP_exon_1_0_chr3R_17183727_r	0	-
chr3R	17200781	17201634	CG32491-RP_exon_2_0_chr3R_17200782_r	0	-
chr3R	17202323	17202463	CG32491-RP_exon_3_0_chr3R_17202324_r	0	-
chr3R	17202540	17202798	CG32491-RP_exon_4_0_chr3R_17202541_r	0	-
chr3R	17203009	17203121	CG32491-RP_exon_5_0_chr3R_17203010_r	0	-
chr3R	17184011	17184791	CG32491-RK_exon_0_0_chr3R_17184012_r	0	-
chr3R	17200781	17201634	CG32491-RK_exon_1_0_chr3R_17200782_r	0	-
chr3R	17202323	17202463	CG32491-RK_exon_2_0_chr3R_17202324_r	0	-
chr3R	17202540	17202798	CG32491-RK_exon_3_0_chr3R_17202541_r	0	-
chr3R	17203009	17203121	CG32491-RK_exon_4_0_chr3R_17203010_r	0	-
chr3R	17184021	17184318	CG32491-RL_exon_0_0_chr3R_17184022_r	0	-
chr3R	17200781	17201634	CG32491-RL_exon_1_0_chr3R_17200782_r	0	-
chr3R	17202323	17202463	CG32491-RL_exon_2_0_chr3R_17202324_r	0	-
chr3R	17202540	17202798	CG32491-RL_exon_3_0_chr3R_17202541_r	0	-
chr3R	17203009	17203121	CG32491-RL_exon_4_0_chr3R_17203010_r	0	-
chr3R	17186111	17186276	CG32491-RT_exon_0_0_chr3R_17186112_f	0	.
chr3R	17186349	17187009	CG32491-RT_exon_1_0_chr3R_17186350_f	0	.
chr3R	17200781	17201634	CG32491-RT_exon_2_0_chr3R_17200782_f	0	.
chr3R	17202323	17202463	CG32491-RT_exon_3_0_chr3R_17202324_f	0	.
chr3R	17202540	17202798	CG32491-RT_exon_4_0_chr3R_17202541_f	0	.
chr3R	17203009	17203121	CG32491-RT_exon_5_0_chr3R_17203010_f	0	.
chr3R	17187119	17187332	CG32491-RZ_exon_0_0_chr3R_17187120_f	0	.
chr3R	17187391	17187860	CG32491-RZ_exon_1_0_chr3R_17187392_f	0	.
chr3R	17200781	17201634	CG32491-RZ_exon_2_0_chr3R_17200782_f	0	.
chr3R	17202323	17202463	CG32491-RZ_exon_3_0_chr3R_17202324_f	0	.
chr3R	17202540	17202798	CG32491-RZ_exon_4_0_chr3R_17202541_f	0	.
chr3R	17203009	17203121	CG32491-RZ_exon_5_0_chr3R_17203010_f	0	.
chr3R	17187909	17188590	CG32491-RM_exon_0_0_chr3R_17187910_r	0	-
chr3R	17200781	17201634	CG32491-RM_exon_1_0_chr3R_17200782_r	0	-
chr3R	17202323	17202463	CG32491-RM_exon_2_0_chr3R_17202324_r	0	-
chr3R	17202540	17202798	CG32491-RM_exon_3_0_chr3R_17202541_r	0	-
chr3R	17203009	17203121	CG32491-RM_exon_4_0_chr3R_17203010_r	0	-
chr3R	17188688	17189606	CG32491-RE_exon_0_0_chr3R_17188689_r	0	-
chr3R	17200781	17201634	CG32491-RE_exon_1_0_chr3R_17200782_r	0	-
chr3R	17202323	17202463	CG32491-RE_exon_2_0_chr3R_17202324_r	0	-
chr3R	17202540	17202798	CG32491-RE_exon_3_0_chr3R_17202541_r	0	-
chr3R	17203009	17203121	CG32491-RE_exon_4_0_chr3R_17203010_r	0	-
chr3R	17189739	17190097	CG32491-RAB_exon_0_0_chr3R_17189740_r	0	-
chr3R	17200781	17201634	CG32491-RAB_exon_1_0_chr3R_17200782_r	0	-
chr3R	17202323	17202463	CG32491-RAB_exon_2_0_chr3R_17202324_r	0	-
chr3R	17202540	17202798	CG32491-RAB_exon_3_0_chr3R_17202541_r	0	-
chr3R	17203009	17203121	CG32491-RAB_exon_4_0_chr3R_17203010_r	0	-
chr3R	17190173	17190367	CG32491-RC_exon_0_0_chr3R_17190174_r	0	-
chr3R	17190435	17190714	CG32491-RC_exon_1_0_chr3R_17190436_r	0	-
chr3R	17200781	17201634	CG32491-RC_exon_2_0_chr3R_17200782_r	0	-
chr3R	17202323	17202463	CG32491-RC_exon_3_0_chr3R_17202324_r	0	-
chr3R	17202540	17202798	CG32491-RC_exon_4_0_chr3R_17202541_r	0	-
chr3R	17203009	17203121	CG32491-RC_exon_5_0_chr3R_17203010_r	0	-
chr3R	17191725	17192060	CG32491-RY_exon_0_0_chr3R_17191726_f	0	.
chr3R	17200781	17201634	CG32491-RY_exon_1_0_chr3R_17200782_f	0	.
chr3R	17202323	17202463	CG32491-RY_exon_2_0_chr3R_17202324_f	0	.
chr3R	17202540	17202798	CG32491-RY_exon_3_0_chr3R_17202541_f	0	.
chr3R	17203009	17203121	CG32491-RY_exon_4_0_chr3R_17203010_f	0	.
chr3R	17192171	17192466	CG32491-RX_exon_0_0_chr3R_17192172_f	0	.
chr3R	17200781	17201634	CG32491-RX_exon_1_0_chr3R_17200782_f	0	.
chr3R	17202323	17202463	CG32491-RX_exon_2_0_chr3R_17202324_f	0	.
chr3R	17202540	17202798	CG32491-RX_exon_3_0_chr3R_17202541_f	0	.
chr3R	17203009	17203121	CG32491-RX_exon_4_0_chr3R_17203010_f	0	.
chr3R	17193631	17193960	CG32491-RW_exon_0_0_chr3R_17193632_f	0	.
chr3R	17200781	17201634	CG32491-RW_exon_1_0_chr3R_17200782_f	0	.
chr3R	17202323	17202463	CG32491-RW_exon_2_0_chr3R_17202324_f	0	.
chr3R	17202540	17202798	CG32491-RW_exon_3_0_chr3R_17202541_f	0	.
chr3R	17203009	17203121	CG32491-RW_exon_4_0_chr3R_17203010_f	0	.
chr3R	17194101	17194784	CG32491-RV_exon_0_0_chr3R_17194102_f	0	.
chr3R	17200781	17201634	CG32491-RV_exon_1_0_chr3R_17200782_f	0	.
chr3R	17202323	17202463	CG32491-RV_exon_2_0_chr3R_17202324_f	0	.
chr3R	17202540	17202798	CG32491-RV_exon_3_0_chr3R_17202541_f	0	.
chr3R	17203009	17203121	CG32491-RV_exon_4_0_chr3R_17203010_f	0	.
chr3R	17195183	17195967	CG32491-RU_exon_0_0_chr3R_17195184_f	0	.
chr3R	17200781	17201634	CG32491-RU_exon_1_0_chr3R_17200782_f	0	.
chr3R	17202323	17202463	CG32491-RU_exon_2_0_chr3R_17202324_f	0	.
chr3R	17202540	17202798	CG32491-RU_exon_3_0_chr3R_17202541_f	0	.
chr3R	17203009	17203121	CG32491-RU_exon_4_0_chr3R_17203010_f	0	.
chr3R	17195821	17196364	CG32491-RS_exon_0_0_chr3R_17195822_r	0	-
chr3R	17200781	17201634	CG32491-RS_exon_1_0_chr3R_17200782_r	0	-
chr3R	17202323	17202463	CG32491-RS_exon_2_0_chr3R_17202324_r	0	-
chr3R	17202540	17202798	CG32491-RS_exon_3_0_chr3R_17202541_r	0	-
chr3R	17203009	17203121	CG32491-RS_exon_4_0_chr3R_17203010_r	0	-
chr3R	17196654	17196949	CG32491-RAA_exon_0_0_chr3R_17196655_r	0	-
chr3R	17200781	17201634	CG32491-RAA_exon_1_0_chr3R_17200782_r	0	-
chr3R	17202323	17202463	CG32491-RAA_exon_2_0_chr3R_17202324_r	0	-
chr3R	17202540	17202798	CG32491-RAA_exon_3_0_chr3R_17202541_r	0	-
chr3R	17203009	17203121	CG32491-RAA_exon_4_0_chr3R_17203010_r	0	-
chr3R	17197044	17197789	CG32491-RO_exon_0_0_chr3R_17197045_r	0	-
chr3R	17200781	17201634	CG32491-RO_exon_1_0_chr3R_17200782_r	0	-
chr3R	17202323	17202463	CG32491-RO_exon_2_0_chr3R_17202324_r	0	-
chr3R	17202540	17202798	CG32491-RO_exon_3_0_chr3R_17202541_r	0	-
chr3R	17203009	17203121	CG32491-RO_exon_4_0_chr3R_17203010_r	0	-
chr3R	17197884	17198802	CG32491-RN_exon_0_0_chr3R_17197885_r	0	-
chr3R	17200781	17201634	CG32491-RN_exon_1_0_chr3R_17200782_r	0	-
chr3R	17202323	17202463	CG32491-RN_exon_2_0_chr3R_17202324_r	0	-
chr3R	17202540	17202798	CG32491-RN_exon_3_0_chr3R_17202541_r	0	-
chr3R	17203009	17203121	CG32491-RN_exon_4_0_chr3R_17203010_r	0	-