[galaxy-user] Minimum length of read segments

Dear All, I am going to run Tophat with RNA-seq dataset to observe alternative splicing events. There is a parameter for Tophat: "Minimum length of read segment". According to "implemented Tophat options", the description for "Minimum length of read segment" is "Each read is cut up into segments, each at least this long. These segments are mapped independently. The default is 25". The length of my reads is 36bps, should I change this parameter based on the length of my reads? How long should I input? Thanks. Jianguang Du