BEDTools - mergeBed -s option?

[yuanzhi]

I am trying to use BEDTools - mergeBed to merge overlapping exons downloaded from UCSC. My goal is to find how many SNPs on the chr10 exons.

I noticed that in the UCSC exon bed file

chr10 82827 84054 NM_001164154_exon_0_0_chr10_82828_r 0 -
chr10 84554 84665 NM_001164154_exon_1_0_chr10_84555_r 0 -
chr10 84743 84852 NM_001164154_exon_2_0_chr10_84744_r 0 -
chr10 85347 85504 NM_001164154_exon_3_0_chr10_85348_r 0 -
chr10 170423 170832 NM_212479_exon_0_0_chr10_170424_f 0 +
chr10 215933 216068 NM_212479_exon_1_0_chr10_215934_f 0 +
chr10 245828 245988 NM_212479_exon_2_0_chr10_245829_f 0 +

some exons are on the "-" strand, and some are on the "+" strand. I am wondering if I need use

mergeBed -s -i input.bed > output.bed

to only merge exons that are on the same strand.

This kind of strand issue has confused me for quite a long time...

Thanks for all your help in advance

-YZ