Brazilian Archives of Biology and Technology
versão impressa ISSN 1516-8913
ESMAELIZAD, Majid; NIARAKI, Saber Jelokhani e FESHARAKI, Reza Hashemi. Molecular and phylogenetic analysis of the partial tams1 gene sequence of a vaccine strain of Theileria annulata. Braz. arch. biol. technol. [online]. 2011, vol.54, n.6, pp. 1109-1116. ISSN 1516-8913. http://dx.doi.org/10.1590/S1516-89132011000600005.
The polypeptide Tams1 is an immunodominant major merozoite piroplasm surface antigen of the protozoan parasite Theileria annulata and is highly variable. In this study, the partial nucleotide (nt) sequence of the Tams1 (522 nt) gene of Iranian vaccine strain (Vaccine-ir68) recovered from an outbreak of disease in Iran was determined and compared with the corresponding sequences of eighteen previously published Tams1 genes. According to sequencing result, a novel amino acid substitution at the Tams1 region (K→Q) was found exclusively in isolate Vaccine-ir68. Genetic distance values, estimated from the sequence data, revealed striking sequence homology (approximately 99%) between Vaccine-ir68 isolate and Tunisian isolates, showing that they were same isolates of T. annulata which were spread in these areas. The phylogenetic tree constructed based on the sequence alignment of 19 Tams1 coding regions was distinctly divided into five lineages. There might be some unknown tick carrier birds immigrating to the different geographical regions. These birds have an effective role to distribute the T. annulata species in North Africa, Palestine and Iran.
Palavras-chave : Tams1; Theileria Annulata; merozoite surface antigen; phylogenetic.