Abstract:
The cattle tick, Rhipicephalus microplus, has a debilitating effect on the livestock industry worldwide,
owing to its being a vector of the causative agents of bovine babesiosis and anaplasmosis. In South Africa,
co-infestation with R. microplus and R. decoloratus, a common vector species on local livestock, occurs
widely in the northern and eastern parts of the country. An alternative to chemical control methods is
sought in the form of a tick vaccine to control these tick species. However, sequence information and
transcriptional data for R. decoloratus is currently lacking. Therefore, this study aimed at identifying genes
that are shared between midgut tissues of feeding adult female R. microplus and R. decoloratus ticks. In this
regard, a custom oligonucleotide microarray comprising of 13,477 R. microplus sequences was used for
transcriptional profiling and 2476 genes were found to be shared between these Rhipicephalus species.
In addition, 136 transcripts were found to be more abundantly expressed in R. decoloratus and 1084
in R. microplus. Chi-square analysis revealed that genes involved in lipid transport and metabolism are
significantly overrepresented in R. microplus and R. decoloratus. This study is the first transcriptional
profiling of R. decoloratus and is an additional resource that can be evaluated further in future studies for
possible tick control.
