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The Cape mountain zebra ( Equus zebra zebra ) is a subspecies of mountain zebra endemic to South Africa. The Cape mountain zebra experienced near extinction in the early 1900’s and their numbers have since recovered to more than 4,800 individuals. However, there are still threats to their long-term persistence. A previous study reported that Cape mountain zebra had low genetic diversity in three relict populations and that urgent conservation management actions were needed to mitigate the risk of further loss. As these suggestions went largely unheeded, we undertook the present study, fifteen years later to determine the impact of management on genetic diversity in three key populations. Our results show a substantial loss of heterozygosity across the Cape mountain zebra populations studied. The most severe losses occurred at De Hoop Nature Reserve where expected heterozygosity reduced by 22.85% from 0.385 to 0.297. This is alarming, as the De Hoop Nature Reserve was previously identified as the most genetically diverse population owing to its founders originating from two of the three remaining relict stocks. Furthermore, we observed a complete loss of multiple private alleles from all populations, and a related reduction in genetic structure across the subspecies. These losses could lead to inbreeding depression and reduce the evolutionary potential of the Cape mountain zebra. We recommend immediate implementation of evidence-based genetic management and monitoring to prevent further losses, which could jeopardise the long term survival of Cape mountain zebra, especially in the face of habitat and climate change and emerging diseases.

Translocation of animals in fragmented habitats is an important means of dispersal and gene flow, however, the movement of animals has led to the spread of various diseases globally and wildlife are often the reservoirs of these diseases. Currently, Cape mountain zebra are translocated within South Africa as a management method for augmentation of isolated and fragmented populations. The movement of pathogens due to translocations in local regions have gone largely unchecked, particularly where there may still be isolated regions that can be negatively affected. Equine piroplasmosis is a tick-borne disease caused by Theilaria equi and/or Babesia caballi reported to occur in equids (Bhoora et al., 2010; Zweygarth et al., 2002). Here, the presence of T. equi and B. caballi was detected in 137 clinically healthy Cape mountain zebra from three South African reserves, Mountain Zebra National Park (MZNP), De Hoop Nature Reserve (DHNR) and Karoo National Park (KNP) using the multiplex EP real-time PCR (qPCR) assay. We observed 100% prevalence for T. equi and identified only one animal from MZNP with B. caballi. These results affirm that precautions should be taken prior to founding new populations of Cape mountain zebra and that potential farms and properties adjacent to prospective reserves should be screened for the presence of the organisms in order to mitigate risks of infection to domestic animals.

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Since CD8 + T cells play an important role in resistance to infection with heartwater, effective vaccines against this disease will likely require identification of antigens that contain CD8 + T cell epitopes responsible for cytotoxic T lymphocyte (CTL) responses. With the use of the fluorescent antigen-transfected target cell (FATT)-CTL assay, IFN-γ ELISPOT and flow cytometry, peptides that induce CTL, proliferation of CD8+T cells and IFN-γ production were identified as possible target antigens for vaccine development. Of particular relevance was the finding that different peptides from different antigens were able to elicit varied cytotoxic activities by immune peripheral blood mononuclear cells (PBMC) from heartwater immune tick-infected sheep. Several peptides derived from Erum0660, Erum2330, Erum2540, Erum2580 and Erum5000 induced CTL in immune sheep PBMC. Peptide Erum2540-6 was the only peptide that induced significant CTL, CD8 + CD45RO + and CD8 + IFN-γ + by PBMC from all three sheep, and Erum2540 and p2540-20 induced the highest % CTL response in all three outbred sheep. These results suggest that these epitopes may be of major importance in heartwater recombinant vaccine development.

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The Cape mountain zebra (Equus zebra zebra) has recovered from near extinction over more than eight decades. While their numbers have increased, populations remain isolated with low genetic diversity. With more than 75 new populations being founded and more than 4800 extant animals, conservation management strategies are being implemented to mitigate risk of losses in genetic diversity and reproductive fitness. One objective is to identify reproductive characteristics that may improve population growth. Cation channel sperm (CatSper) genes play an important role in hyperactivation of sperm during fertilization. Mutations in these genes lead to reduced fertility and even infertility. Ten male zebras were sampled from a group that were translocated in 2016 in order to found a new population. Single nucleotide polymorphisms (SNPs) were identified in three of the CatSper genes (1 - 3). Lack of variation was observed in all exons, with only four SNPs being identified in the intronic regions in close proximity to exons 1, 2, 7, 8, and 9 of CatSper 1. These results may contribute to the pre-identification of males for new founder populations to ensure population growth and viability, and may be a useful tool for selection against low-producing individuals.