Sequence and phylogenetic analysis of Internal Transcribed Spacer (ITS-1) ribosomal DNA sequence of Fasciola gigantica isolated from Bareilly

Adult Fasciola gigantica (tropical live fluke) flukes were collected from the buffalo slaughtered at Bareilly slaughter house and Internal Transcribed Spacer-1 (ITS-1) gene of ribosomal DNA was characterized. The DNA was extracted from head portion of the liver fluke and ITS-1 gene was amplified by polymerase chain reaction (PCR). The purified PCR amplicon was cloned into pGEM-T easy cloning vector and sequenced by Sanger's dideoxy method. Sequencing of recombinant clone revealed that the length of the ITS-1 was 433 bp comprising 422 bp of complete ITS-1 gene. While comparing with published ITS-1 sequences of F. gigantica isolates from NCBI published sequences, 98.8% homology was observed with published sequences of various countries, and 99% homology with Meghalaya strain of F. gigantica. The variations were observed at 24^th, 114^th 208^th, 286^th and 306^th positions. On the basis of sequence analysis, it was found that enzyme RsaI could be used for restriction fragment length polymorphism (RFLP) analysis. The present study could be helpful in molecular taxonomic identification of Fasciola species.