Genetic
Characterization of Fasciola
Samples from Bovine Hosts in Pakistan by
Sequences of Ribosomal
Internal Transcribed Spacer
Regions
SairaMufti1, Kiran Afshan1, Imtiaz Ahmad Khan2*, Yusuf Zafar3, Syed Shakeel Raza Rizvi4, Farhat Nazir5 and Mazhar Qayyum1*
1Department of Zoology and Biology, Faculty of
Sciences; 2Department of Pathobiology, Faculty of
Veterinary and Animal Sciences, PMAS-Agriculture University,
Rawalpindi-46300, Pakistan; 3Agriculture
and Biotechnology, Biosciences Division, Pakistan Atomic Energy
Commission, Islamabad, Pakistan; 4Pakistan Science
Foundation, Constitution Avenue, Islamabad; 5National Institute for Genomics and Advanced
Biotechnology, Islamabad, Pakistan *Corresponding author: imtiazarana@uaar.edu.pk (IAK); mazhar_dr@yahoo.com (MQ)
Abstract
In present study, 50
samples representing Fasciola (Platyhelminthes:
Trematoda: Digenea) from cattle and buffaloes of Pothwar region were
characterized genetically by sequences of the first (ITS-1) and second (ITS-2)
internal transcribed spacers (ITS) of nuclear ribosomal DNA (rDNA). The ITS rDNA
was amplified from individual liver flukes by polymerase chain reaction (PCR),
and the amplicons were sequenced directly. The lengths of the FG ITS-1 and ITS-2
sequences were 391 and 329 bp, respectively, for all
Fasciola gigantica samples sequenced.
For Fasciola hepatica samples
sequenced, FH ITS-1 was not amplified and length for ITS-2 sequences was 330 bp.
Molecular identification using rDNA internal transcribed spacer 1 and
2 characterizes
Fasciolaspp. in Pothwar to
be an intermediate/ hybrid resembling
more with F. gigantica. The
results also indicated that Fasciola spp
in cattle and buffalo are genetically
similar, as both hosts' possess
Fasciola with the same number of base
pairs in their internal transcribed spacers as proved by gel
electrophoresis and sequencing. To
determine the phylogenic location of
Fasciola spp. of Pakistan based on rDNA molecular data, ribosomal ITS
regions were sequenced and compared with other fasciolid species from NCBI
databases for sequence homology analysis using BLAST and ClustalW programs. The
phylogenetic trees revealed a close relationship with isolates of
F. gigantica from China, India, Iran
and Vietnam. This is the first demonstration of the existence of hybrid or an
intermediate Fasciola species in
Pakistan by a genetic approach, which provides foundation for further studies in
different agro ecological zones of Pakistan.