Characterization of Internal Transcribed Spacer of Nuclear Ribosomal DNA of Trichuris ovis from Goat in Hunan Province, China

Abstract

Trichuris ovis parasitizes the caeca and colon of hosts, causing trichuriasis. Despite this parasite being of animal health significance, causing considerable socio-economic losses globally, little is known of the molecular characteristics of T. ovis. In the present study, the entire first and second internal transcribed spacer (ITS-1 and ITS-2) regions of nuclear ribosomal DNA (rDNA) of T. ovis from goats in Hunan province, China were amplified by polymerase chain reaction (PCR), and the representative amplicons were subjected to sequencing in order to estimate sequence variation. The ITS rDNA sequences for the T. ovis samples were 1289-1303 bp in length. Sequence analysis revealed that the ITS-1 rDNA, 5.8S and ITS-2 rDNA of these whipworms were 725-734 bp, 163 bp and 401-406 bp in size, respectively. Sequence variation in ITS rDNA within and among T. ovis was also examined. Excluding nucleotide variations in the simple sequence repeats, the intra-species sequence variation in the ITS-1 was 0-2.7%, and ITS-2 was 0-4.1%. The inter-species sequence variation among the T. ovis and other whipworms were more than 45.7% for ITS-1 rDNA and 51.3% for ITS-2 rDNA. These results demonstrated that the ITS rDNA sequences provide additional genetic markers for the identification and differentiation of the T. ovis. These data should be useful for studying the epidemiology, population genetics of T. ovis, as well as for the diagnosis of trichuriasis in sheep and goats.