ANIMAL BIODIVERSITY AND EMERGING DISEASES Comparison of the Molecular Structure of the TaSP Gene of Theileria annulata from Sudanese Isolates Awadia M. Ali, a,b Diaeldin Salih, c Mohammed Bakheit, d Abdel Rahim M. El Hussein, c Shawgi M. Hassan, a Maowia M. Mukhtar, e Jabbar S. Ahmed, b and Ulrike Seitzer b a Faculty of Veterinary Medicine, University of Khartoum, Khartoum North, Sudan b Division of Veterinary Infection Biology and Immunology, Research Center Borstel, Borstel, Germany c Central Veterinary Research Laboratories, Al Amarat, Khartoum, Sudan d National Research Center for Protozoan Diseases, Unit for Diseases Control and Genetics, Obihiro University for Agriculture and Veterinary Medicine, Inada-cho, Obihiro, Japan e Institute of Endemic Diseases, University of Khartoum, Khartoum, Sudan The polymorphic region of the Theileria annulata surface protein (TaSP) was cloned and sequenced from different isolates of cattle and cell lines from different areas of Sudan. Amino acid sequence alignment revealed a high diversity showing amino acid and length polymorphism, both within and between parasite isolates. The generation of TaSP diversity may allow the evasion of host immunity by the parasite since TaSP is a highly antigenic parasite protein. Key words: alignment; genotype; Theileria annulata; Sudan Introduction Theileria annulata, the causative agent of trop- ical theileriosis, is a tick-borne protozoan para- site. Tropical theileriosis constitutes one of the obstacles for improved livestock production in many countries. In the Sudan, the disease is considered as the most important tick-borne disease. 1 No data is available regarding the genotypes of this Theileria parasite in Sudan. This study investigated the molecular struc- ture of the single copy polymorphic T. annulata surface protein (TaSP ) gene 2 for comparison of strains isolated from cattle and cell lines in Sudan. Address for correspondence: Dr. Ulrike Seitzer, Veterinary Infection Biology and Immunology, Research Center Borstel, Parkallee 22, 23845 Borstel, Germany. Voice: +49-(0)4537-188-413; fax +49-(0)4537-188- 627. useitzer@fz-borstel.de Materials and Methods Cell Lines and Field Samples The parasite isolates and field samples from different geographical regions of the Sudan used in this study and the number of clones analyzed per sample are summarized in Table 1. Sequence Analysis Genomic DNA was amplified, cloned, and sequenced as described previously. 2 Analysis of the variable region of TaSP was performed by comparing the sequences from the various isolates (GenBank accession EU032540- EU032577). A total of 38 clones (one to four clones of independent PCR reactions) were se- quenced. The predicted amino acid sequences Animal Biodiversity and Emerging Diseases: Ann. N.Y. Acad. Sci. 1149: 218–220 (2008). doi: 10.1196/annals.1428.025 C  2008 New York Academy of Sciences. 218