diff --git a/README.md b/README.md
index 06700c1f9366ea3f7ccab5d2a6338a127e8a6841..a681ce9d0265e856cc27d4b0d3d47bee5d3fcffd 100644
--- a/README.md
+++ b/README.md
@@ -100,7 +100,7 @@ Parameter and command examples are shown below.
 1. [SyntenyLink.sh](#syntenyLink.sh) 
     - -i Input collinear file
     - -s Ploidy status. If diploid 2, tetraploid 4, hexaploid 6, octaploid 8
-    - -p Gene prefix. 
+    - -p Gene prefix (for example 'G' is the gene prefix for this gene AT1G01010; where we could separate the chromsome number part from the integer part)
     - -gt Groundtruth subgenome separation. Default is None
     - -bed Query bed file
     - -chr<i> Chromosome number for each subgenome. For example in Brassica napus chr1 is 10 and chr2 is 9