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We have developed a polymerase chain reaction-sequence-specific primers-restriction fragment length polymorphism (PCR-SSP-RFLP) method to rapidly differentiate between the A18 and A18 variant (v) BoLA haplotypes and between A14 and A15/A15v BoLA haplotypes in Holstein/Friesian cattle. We used published SSP to PCR amplify BoLA alleles expressed in animals of known haplotype and exposed the amplicons to the restriction enzyme PvuII that was predicted to cut at a unique site in the middle of BoLA-6*01302 (A18v) and BoLA-1*00901 (A15) but not in BoLA-6*01301 (A18) or BoLA-1*02301 (A14) alleles. Whereas the method does not discriminate between the A15 and A15v haplotypes, as the BoLA-1*00902 allele associated with A15v also contains a PvuII site, we are interested in cattle of A18 and A14 haplotype for vaccine related studies. Our results also indicated that the BoLA-6*01302 (A18v) allele is much more abundant than BoLA-6*01301 (A18) in the cattle that we sampled.

Organophosphate resistant and susceptible tick larvae from laboratory strains of the southern cattle tick, Rhipicephalus (Boophilus) microplus were exposed to low doses of the organophosphate (OP) acaricide, coumaphos. Serial analysis of gene expression (SAGE) was used to analyse differential gene expression in response to OP treatment and to compare the responses of OP-treated and -untreated resistant and susceptible tick larvae. An R. microplus Gene Index was used as an EST database to identify genes which corresponded to SAGE tags whose abundance changed in response to acaricide exposure. Relative quantitative RT-PCR was used to confirm the differential expression results from the SAGE experiments. Of particular interest is a SAGE tag which corresponds to a cytochrome P450-like EST in the Gene Index which was more abundant in untreated OP resistant larvae compared to untreated OP susceptible larvae. This SAGE tag was also more abundant in OP resistant larvae treated with OP compared to OP susceptible larvae treated with OP.

Theileria annulata and Theileria parva both possess a major surface antigen on the sporozoite stage of the life-cycle, called SPAG-1 and p67, respectively. In each case, these antigens are vaccine candidates and have been shown to induce a degree of homologous protection in earlier work. These antigens share sequence homology and are serologically cross-reactive. Here, we confirm that these antigens confer protection against homologous species challenge. More importantly, they mutually confer a degree of cross-species protection raising the prospect of a common vaccine in the future.