Abstract: A Cowdria ruminantium DNA fragment (4.2 Kb) cloned in a pGEM plasmid vector was 58 % sequenced, using a "primer walking strategy" in a thermo cycling silver sequencing technique. The aim of this experiment was to sequence the cloned insert and predict its immunogenic proteins by an in vitro transcription/translation assay. Incomplete nucleotide sequences of 1265 and 1201 base pairs in length were obtained, respectively from the 5’ (T7 sequence) and 3’ (Sp6 sequence) ends of the insert. These sequences were 70% A+T rich in composition. Homology search (BLAST) of the translated sequences against the genebank database identified significant similarities with two proteins of known functions from the T7 sequence and a non-specified cell division protein from the Sp6 sequence. Two major immunogenic proteins of 55 and 27 KDa were revealed by in vitro transcription/translation assay. Although the HW19 DNA fragment is incompletely sequenced, the two immunogenic proteins revealed may have a significant application for the development of improved serological diagnostic tests and/or subunit vaccine against heartwater.
A. Ngakou , A. Ngakou and M.D. Achukwi , 2006. Molecular Characterisation of a HW 19 Cowdria ruminantium DNA Fragment for Development of Serological Assays Against Heartwater. Journal of Animal and Veterinary Advances, 5: 990-994.