Sequence polymorphism analysis of the ITS-1 gene of Leishmania donovani isolates from different epidemic foci in China.

Objective To determine whether the first internal transcribed spacer ( ITS-1) of ribosomal DNA ( rDNA) could be used as a genetic marker of Leishmania donovani with different geographic origins in China.Methods The ITS-1 rDNA from L.d.SD1 isolate,L.d.SC7 isolate,L.d.XJ3 isolate,and L.d.JS12 isolate was amplified by PCR,cloned,sequenced,and then analyzed for sequence polymorphism.Results ITS-1 from L.d.SD1 isolate,L.d.SC7 isolate,L.d.XJ3 isolate,and L.d.JS12 isolate had a sequence size of 317 bp,323 bp,317 bp,and 316 bp,respectively.Different types of mutations occurred in the four sequences of ITS-1.Mutation of the ITS-1 from L.d.JS12 isolate in particular was the most frequent and its sequence polymorphism was the most significant.Conclusion ITS-1 can serve as a molecular genetic marker of Leishmania donovani with different geographic origins in China.