Ehrlichia ruminantium, which is transmitted by ticks and lives inside of the cells of its host, has a genome length of approximately 1.5 million base pairs. Only about two-thirds of the genome appears to be coding sequence, encoding about 900 proteins and 40 RNA species, the scientists found. In addition, the genome contains a large number of tandem repeats and duplicated sequences.
The genome sequence is expected to facilitate the search for vaccine candidate genes, the scientists say in their report, published online this week in PNAS. There is no effective vaccine yet for heartwater, which occurs throughout sub-Saharan Africa and in the Caribbean and threatens to invade North and