#### Calculating expression values from single-end data
For single-end models, users have the option of providing a fragment
-length distribution via the --fragment-length-mean and
---fragment-length-sd options. The specification of an accurate fragment
+length distribution via the '--fragment-length-mean' and
+'--fragment-length-sd' options. The specification of an accurate fragment
length distribution is important for the accuracy of expression level
estimates from single-end data. If the fragment length mean and sd are
not provided, RSEM will not take a fragment length distribution into
By default, RSEM automates the alignment of reads to reference
transcripts using the Bowtie alignment program. To use an alternative
alignment program, align the input reads against the file
-'reference_name.idx.fa' generated by rsem-prepare-reference, and format
+'reference_name.idx.fa' generated by 'rsem-prepare-reference', and format
the alignment output in SAM or BAM format. Then, instead of providing
-reads to rsem-calculate-expression, specify the --sam or --bam option
+reads to 'rsem-calculate-expression', specify the '--sam' or '--bam' option
and provide the SAM or BAM file as an argument. When using an
-alternative aligner, you may also want to provide the --no-bowtie option
-to rsem-prepare-reference so that the Bowtie indices are not built.
+alternative aligner, you may also want to provide the '--no-bowtie' option
+to 'rsem-prepare-reference' so that the Bowtie indices are not built.
+
+Some aligners' (other than Bowtie) output might need to be converted
+so that RSEM can use. For conversion, please run
+
+ convert-sam-for-rsem --help
+
+to get usage information or visit the [convert-sam-for-rsem
+documentation
+page](http://deweylab.biostat.wisc.edu/rsem/convert-sam-for-rsem.html).
However, please note that RSEM does ** not ** support gapped
alignments. So make sure that your aligner does not produce alignments