Detection and molecular characterization of equine infectious anemia virus in Mongolian horses

Abstract

The genetic characterization and actual prevalence of EIAV in Mongolian horse in the disease endemic region is currently unknown. Here, 11 of 776 horse serum samples from four Mongolian provinces tested positive on agar gel immunodiffusion test. Genomic DNA extracted from all seropositive samples was subjected to nested PCR assay. Among these, three samples tested positive with nested PCR assay and were identified by sequencing analysis based on long termination repeat and tat gene of the virus. Two of the three sequences were identical, with 94.0% identity with the third. These two independent Mongolian EIAV sequences were retained functional motifs, with no dramatic changes but some variability in the U5 region; they were clustered with genotypes from European countries but not with those from China, U.S.A., or Japan.

Keywords: LTR-gene; Mongolia; equine infectious anemia virus; horse; molecular epidemiology.

Fig. 1.

Comparison of LTR nucleotide sequences between Mongolian EIAV and other isolates. Structural and putative transcriptional control elements were predicted based on previous reports [5]. Dashes (−) indicate deletions, and dots (·) indicate conserved residues. Identical residues are boxed.

Fig. 2.

Phylogenetic trees of this study were constructed by MEGA 7 program with the neighbor-joining method by using the sequences based on the LTR and tat gene of EIAV identified in this study and database sequences in GenBank.