Update topics/variant-analysis/tutorials/baculovirus-isolate-variatio…

…n/tutorial.md

Co-authored-by: Wolfgang Maier <maierw@posteo.de>

topics/variant-analysis/tutorials/baculovirus-isolate-variation/tutorial.md

@@ -611,7 +611,7 @@ As a result, we get a SNV plot that shows the relative frequency of the first al
 
 # SNV Specificity Determination
 
-Now we come to the last but most complex section of this tutorial - determining SNV specificities. We have seen that CpGV-V15 is a mixed isolate. Now we want to find out which isolates were mixed and how this SNV pattern can be explained. In the next step, we will consider  SNV positions as markers and look for SNV positions that are only variable for one or more sequenced isolates of CpGV. If an SNV position is only variable for CpGV-S (i.e. the relative frequency is greater than 0; `REL.ALT > 0`) but is equal to zero for the other isolates, then this position is a marker for CpGV-S, or specific for CpGV-S. Since we cannot perform this determination by hand for all positions, I have written a small program implemented in the **Text reformatting with awk** tool that does the work for us. 
+Now we come to the last but most complex section of this tutorial - determining SNV specificities. We have seen that CpGV-V15 is a mixed isolate. Now we want to find out which isolates were mixed and how this SNV pattern can be explained. In the next step, we will consider  SNV positions as markers and look for SNV positions that are only variable for one or more sequenced isolates of CpGV. If a SNV position is only variable for CpGV-S (i.e. the relative frequency is greater than 0; `REL.ALT > 0`) but is equal to zero for the other isolates, then this position is a marker for CpGV-S, or specific for CpGV-S. Since we cannot perform this determination by hand for all positions, I have written a small program implemented in the **Text reformatting with awk** tool that does the work for us. 
 
 Before we get started, I would like to explain specificity in more detail using an example. First, we decide that we want to determine the specificities for the SNV positions for the following isolates:
 * CpGV-M