Experimental immunology Genetic diversity and phylogenetic analysis of Tams1 of Theileria annulata isolates from three continents between 2000 and 2012

Abstract

Theileria annulata, which is part of the Theileria sergenti/Theileria buffeli/Theileria orientalis group, preferentially infects cattle and results in high mortality and morbidity in the Mediterranean, Middle East, and Central Asia. The polypeptide Tams1 is an immunodominant major merozoite piroplasm surface antigen of T. annulata that could be used as a marker for epidemiological studies and phylogenetic analysis. In the present study, a total of 155 Tams1 sequences were investigated for genetic diversity and phylogenetic relationships through phylogenetic analysis. Results showed that the Tams1 sequences were divided into two major groups and that distribution for some isolates also exhibited geographic specificity. As targeting polymorphic genes for parasite detection may result in underestimation of infection, polymerase chain reaction (PCR) assay using two different probes targeting tams-1 genes of these two groups can be more credible. In addition, the direction of the spread of the disease was discovered to be from the Mediterranean or the tropical zone to the Eurasian peninsula, Middle East, Southern Asia, and Africa, particularly for Group 2. A similar occurrence was also found between the Ms1 gene of Theileria lestoquardi and the Tams1 gene of T. annulata, which explains cross-immunogenicity to a certain extent. However, no potential glycosylation site in the Tams1 of T. annulata was found in this study, which illustrated that instead of N-glycosylation, other modifications have more significant effects on the immunogenicity of the Tams1 protein.

Genetic Profiling Reveals High Allelic Diversity, Heterozygosity and Antigenic Diversity in the Clinical Isolates of the Theileria annulata From India

“…The phylogenetic analysis was performed based on the neighbor-joining method using the tams1 gene sequences of seven Indian parasites (GenBank accession IDs MK034698-MK034704) and 25 previously reported parasites. The clusters were divided into two groups on the basis of previously published data (Wang et al, 2014). C1, C2, and C6 were clustered in group 1 while C4, C5, and V were in group 2 ( Figure 4 ).…”

“…Gblocks program was used to identify the conserved stretches in the genomes. Finally, MEGA7 program was used to calculate the phylogenetic distance between the parasite strains and for drawing a phylogenetic tree using the consensus sequence (Wang et al, 2014). The evolutionary history and phylogenetic tree were generated using the neighbor-joining method.…”

“…The sequencing results were further confirmed by checking the specificity of the sequence using blast analysis. The previously published tams1 gene sequences from the three continents Asia, Africa and Europe were used for calculating the phylogenetic relationship between the strains using MEGA7 software (Wang et al, 2014). Accession number of the sequences that were used U222888.1 (Ankara), Z48739.1 (Ankara), GU130193.1 (Iraq: Kurdistan), AF214819.1 (Mauritania), JX683683.1 (Gansu: China), AF214911.1 (Turkey: Ankara), AF214872.1 (Tunisia: Northern), AY672541.1 (Iran), EU563912.1 (China: Xinjiang), AF214828.1 (Portugal), AF214860.1 (Italy: Northern Sicily), AF214812.1 (Spain: Cáceres), EF618726.1 (India: Chennai), EF618728.1 (India: Chennai), JX648210.1 (South India: Tamil Nadu), AF214840.1 (India: Hissar), AF214891.1 (Tunisia: Northern), AF214861.1 (Italy: Northern Sicily), AF214908.1 (Turkey: Ankara), AF214806.1 (Spain: Cáceres), AF214797.1 (Bahrain), GU130190.1 (Iraq:Kurdistan region), AB690863.1 (Srilanka: Polonnaruwa), GU130192.1 (Iraq: Kurdistan region), EF092918.1 (Iran: Qazvin Boein Zahra).…”

“…As parasite diversity is mainly driven by recombination events, it is having a crucial role in deciding the fate of the parasite control measures. Previous reports have shown genetic diversity among the T. annulata parasites using a panel of 10 micro and minisatellite markers, tams1 gene PCR, and indirect fluorescence assay (IFA) (Shiels et al, 1986; Dickson and Shiels, 1993; Katzer et al, 1998; Gubbels et al, 2000a,b; Wang et al, 2014). The genetic diversity of T. annulata parasites using microsatellite marker have been reported previously from various countries like Oman (Al-Hamidhi et al, 2015), Sudan, Tunisia, Turkey, (Weir et al, 2007, 2011) Portugal (Gomes et al, 2016), and China (Yin et al, 2018).…”

“…The genetic diversity of T. annulata parasites using microsatellite marker have been reported previously from various countries like Oman (Al-Hamidhi et al, 2015), Sudan, Tunisia, Turkey, (Weir et al, 2007, 2011) Portugal (Gomes et al, 2016), and China (Yin et al, 2018). However, the parasite diversity studies from India are very scarce; the few available reports are based on IFA and PCR using 18S rRNA and tams1 genes (Manuja et al, 2006; Wang et al, 2014; George et al, 2015). With significant advancement in the field of genomics and genotyping and with the availability of the T. annulata whole genome sequence, the likelihoods of genotype-based population genetic studies are open.…”