Disease relevance of map1

• We have investigated the nature of natural selection acting on an outer membrane protein, the wsp gene in Wolbachia and its homologue map1 in Cowdria, thought likely to be involved in host-parasite interactions in these bacteria [1].
• Ehrlichia ruminantium major antigenic protein gene (map1) variants are not geographically constrained and show no evidence of having evolved under positive selection pressure [2].
• A genetic map for C. ruminantium with a mean resolution of 290 kb was established, the first for a member of the Ehrlichieae: A total of nine genes or cloned C. ruminantium DNA fragments were mapped to specific KSP:I, RSR:II and SMA:I fragments, including the major antigenic protein gene, map-1 [3].

High impact information on map1

• The regions of the wsp and map1 genes we identified as likely to be involved in host-parasite arms races should be examined in future studies of parasite virulence and host immune responses, and during the design of vaccines [1].
• Our results indicate that the map1 gene cluster is relatively conserved but can be subject to recombination, and differences in the transcription of map1 multigenes in host and vector cell environments exist [4].
• Reverse transcription-PCR on E. ruminantium derived mRNA from infected cells using gene-specific primers revealed that all 16 map1 paralogs were transcribed in endothelial cells [4].
• The map1 multigene family is downstream of a hypothetical transcriptional regulator gene and upstream of the secA gene [5].
• Using genome walking and data from an ongoing E. ruminantium genome sequencing project at the Onderstepoort Veterinary Institute, we found 16 paralogs of the map1 gene tandemly arranged in a 25 kb region of the E. ruminantium genome [5].

Biological context of map1

• All the samples were also examined by PCR amplification and probing for two other Cowdria genes (map1 and pCS20) which have been used for heartwater epidemiology [6].
• Genetic typing was done by restriction fragment length polymorphism or sequencing of map1 amplification products [7].

Anatomical context of map1

• Blood and bone marrow samples from healthy, free-ranging Zimbabwean ungulates were taken during translocation from areas harboring Amblyomma ticks and tested for the presence of C. ruminantium, using a PCR assay based on the C. ruminantium map1 gene [8].

Analytical, diagnostic and therapeutic context of map1

• In a preliminary follow-up study, protection conferred by DNA vaccination with individual gene constructs was not enhanced when the protective constructs were administered in combination (including the map-1 gene of E. ruminantium) [9].

References