Cindy Kim Harper

Specifying and sustaining pigmentation patterns in domestic and wild cats

What Kitty Shares with Kings Although long-studied, the underlying basis of mammalian coat patterns remains unclear. By studying a large number of cat species and varieties, Kaelin et al. (p. 1536) identified two genes, Taqpep and Edn3, as critical factors in the development of feline pigment patterns. Mutations in Taqpep are responsible for the blotched tabby pattern in domestic cats and the unusual coat of wild king cheetahs. Gene expression patterns in cat and cheetah skin suggest that Edn3 is a likely regulator of felid hair color. The findings support a common model for coat and pigment pattern formation in domestic and wild cats. The genes specifying tabby cat coat patterns also affect big cats, including king cheetahs. Color markings among felid species display both a remarkable diversity and a common underlying periodicity. A similar range of patterns in domestic cats suggests a conserved mechanism whose appearance can be altered by selection. We identified the gene responsible for tabby pattern variation in domestic cats as Transmembrane aminopeptidase Q (Taqpep), which encodes a membrane-bound metalloprotease. Analyzing 31 other felid species, we identified Taqpep as the cause of the rare king cheetah phenotype, in which spots coalesce into blotches and stripes. Histologic, genomic expression, and transgenic mouse studies indicate that paracrine expression of Endothelin3 (Edn3) coordinates localized color differences. We propose a two-stage model in which Taqpep helps to establish a periodic pre-pattern during skin development that is later implemented by differential expression of Edn3.

An international parentage and identification panel for the domestic cat (Felis catus)

Seventeen commercial and research laboratories participated in two comparison tests under the auspices of the International Society for Animal Genetics to develop an internationally tested, microsatellite-based parentage and identification panel for the domestic cat (Felis catus). Genetic marker selection was based on the polymorphism information content and allele ranges from seven random-bred populations (n = 261) from the USA, Europe and Brazil and eight breeds (n = 200) from the USA. Nineteen microsatellite markers were included in the comparison test and genotyped across the samples. Based on robustness and efficiency, nine autosomal microsatellite markers were ultimately selected as a single multiplex ‘core’ panel for cat identification and parentage testing. Most markers contained dinucleotide repeats. In addition to the autosomal markers, the panel included two gender-specific markers, amelogenin and zinc-finger XY, which produced genotypes for both the X and Y chromosomes. This international cat parentage and identification panel has a power of exclusion comparable to panels used in other species, ranging from 90.08% to 99.79% across breeds and 99.47% to 99.87% in random-bred cat populations.

West Nile virus infection of Thoroughbred horses in South Africa (2000-2001)

REASONS FOR PERFORMING STUDY West Nile virus (WNV) infection is endemic in southern Africa. With the recent emergence of WNV infection of horses in Europe and the USA the present study was performed to estimate the risk of seroconversion to WNV in a cohort of 488 young Thoroughbred (TB) horses. OBJECTIVES To estimate the risk of seroconversion to WNV among a cohort of South African TB yearlings sold at the 2001 National Yearling Sales (NYS) and to determine whether the risk varied geographically. Two horses were also infected with a recent South African isolate of WNV to evaluate its virulence in horses. METHODS Serum samples were collected from the cohort of 488 TB yearlings at the 2001 NYS. Serum samples that were collected from the same horses at the time that they were identified were sourced from our serum bank. Sera from 243 of the dams that were collected at the time that the foals were identified were also sourced from our serum bank. These sera were subjected to serum neutralisation (SN) tests for antibody to WNV. RESULTS Approximately 11% of yearlings seroconverted to WNV on paired serum samples collected from each animal approximately 12 months apart. Studfarms with WNV-seropositive yearlings were widely distributed throughout South Africa and SN tests on sera from their dams indicated that exposure to WNV was even more prevalent (75%) in this population. Neurological disease was not described in any of the horses included in this study and 2 horses inoculated with a recent lineage 2 South African isolate of WNV showed no clinical signs of disease after infection and virus was not detected in their blood. CONCLUSIONS Infection of horses with WNV is common in South Africa, but infection is not associated with neurological disease. POTENTIAL RELEVANCE In contrast to recent reports from Europe, North Africa, Asia and North America, the results of our field and experimental studies indicated that exposure of horses to the endemic southern African strains of WNV was not associated with neurological disease.

Extraction of nuclear DNA from rhinoceros horn and characterization of DNA profiling systems for white (Ceratotherium simum) and black (Diceros bicornis) rhinoceros

Rhinoceros horn is now worth more, per unit weight, than gold, diamonds, or cocaine. Rhinoceros horn has been used in traditional Asian medicine as a presumed cure for a wide range of ailments. Rhinoceros poaching in South Africa has, on average, more than doubled each year over the past 5 years with the rapid economic growth in east and southeast Asia being assumed to be the primary factor driving the increased demand for horn. Here we report on the characterization of methods for genomic DNA extraction from rhinoceros horn and on DNA profiling systems for white (Ceratotherium simum) and black (Diceros bicornis) rhinoceros. The DNA profiling system described includes 22 short tandem repeat (STR), or microsatellite, markers and a gender marker (ZF1), which have been used previously in various studies on rhinoceros. Using a θ value of 0.1, a conservative estimate of random match probability in 5 white rhinoceros ranged from 1:7.3x10(6) to 1:3.0x10(8). Given that the total population of white rhinoceros is approximately 20,000 such random match probabilities indicate that the genotyping system described provides data which can be used for evidentiary purposes. Furthermore, the methods are appropriate for use in investigations involving trace amounts of rhinoceros horn and the matching of profiles obtained from seized rhinoceros horn with material collected from live animals or poached carcasses.

Comparative Genetics of Sarcoid Tumour-Affected and Non-Affected Mountain Zebra (Equus zebra) Populations

In recent years, South African conservation officials have noted the appearance of sarcoid tumour-like growths in Cape mountain zebra (Equus zebra zebra) populations. In domestic horses (Equus ferus caballus), a genetic predisposition for this bovine papillomavirusinduced tumour is reported. This investigation compared population genetic parameters within tumour-affected populations in Bontebok National Park and Gariep Dam Nature Reserve against Cape mountain zebra populations having few or no tumours in Karoo National Park and Karoo Nature Reserve in South Africa and Hartmanns mountain zebra populations from Namibia. Tumour-affected populations had the lowest levels of expected heterozygosity, gene diversity and polymorphism and highest values of internal relatedness and homozygosity by loci but not reaching levels of significance (P = 0.05). Wrights FIS values indicated an overall deficit of heterozygotes in both affected and non-affected Cape mountain zebra populations. Considerable population substructuring, as indicated by FST values and Bayesian clustering, was revealed among all Cape mountain zebra populations. The results provide support for current conservation policies aimed at increasing levels of genetic diversity in isolated Cape mountain zebra populations.

The carrier prevalence of severe combined immunodeficiency, lavender foal syndrome and cerebellar abiotrophy in Arabian horses in South Africa.

REASONS FOR PERFORMING STUDY The carrier prevalence of severe combined immunodeficiency (SCID), lavender foal syndrome (LFS) and cerebellar abiotrophy (CA) in Arabian foals in South Africa was determined in order to quantify the potential impact of these conditions locally. Furthermore, the carrier prevalence of SCID prior to and following the introduction of a genetic test was compared to evaluate the effect of testing in the population. OBJECTIVES To estimate the carrier prevalence of SCID, LFS and CA in registered purebred Arabians born in South Africa in the 2004/5 and 2009/10 foaling seasons and compare the changes in prevalence in these disorders between the 2 groups of foals. STUDY DESIGN Cross-sectional survey. METHODS Samples were collected from individuals randomly selected from 2 populations of purebred Arabian foals born during the 2004/5 and 2009/10 foaling seasons. Genetic testing for SCID, LFS and CA was performed on DNA extracts using specific polymerase chain reactions, with the products being analysed using fragment analysis on a genetic analyser. RESULTS The carrier prevalence of LFS and CA for the 2009/10 season was 11.7% (95% confidence interval [CI] 7.6-17.0%) and 5.1% (95% CI 2.5-9.1%), respectively, with no statistically significant change in prevalence between the 2004/5 and 2009/10 foaling seasons. However, the carrier prevalence of SCID was found to have decreased significantly from 6.4% (95% CI 4.8-8.3%) in the 2004/5 foals to 3.4% (95% CI 2.2-5.1%) in the 2009/10 foals (P = 0.009). CONCLUSIONS The results of this study indicate that genetic screening of Arabian horses for SCID may have played a role in significantly reducing the carrier prevalence within the breeding population and thereby reducing the birth of clinically affected individuals. This study provides an indication of the positive effect of genetic screening for specific conditions in horses.

Fenced and Fragmented: Conservation Value of Managed Metapopulations

Population fragmentation is threatening biodiversity worldwide. Species that once roamed vast areas are increasingly being conserved in small, isolated areas. Modern management approaches must adapt to ensure the continued survival and conservation value of these populations. In South Africa, a managed metapopulation approach has been adopted for several large carnivore species, all protected in isolated, relatively small, reserves that are fenced. As far as possible these approaches are based on natural metapopulation structures. In this network, over the past 25 years, African lions (Panthera leo) were reintroduced into 44 fenced reserves with little attention given to maintaining genetic diversity. To examine the situation, we investigated the current genetic provenance and diversity of these lions. We found that overall genetic diversity was similar to that in a large national park, and included a mixture of four different southern African evolutionarily significant units (ESUs). This mixing of ESUs, while not ideal, provides a unique opportunity to study the impact of mixing ESUs over the long term. We propose a strategic managed metapopulation plan to ensure the maintenance of genetic diversity and improve the long-term conservation value of these lions. This managed metapopulation approach could be applied to other species under similar ecological constraints around the globe.

Robust forensic matching of confiscated horns to individual poached African rhinoceros

Black and white rhinoceros (Diceros bicornis and Ceratotherium simum) are iconic African species that are classified by the International Union for the Conservation of Nature (IUCN) as Critically Endangered and Near Threatened (http://www.iucnredlist.org/), respectively [1]. At the end of the 19th century, Southern white rhinoceros (Ceratotherium simum simum) numbers had declined to fewer than 50 animals in the Hluhluwe-iMfolozi region of the KwaZulu-Natal (KZN) province of South Africa, mainly due to uncontrolled hunting [2,3]. Efforts by the Natal Parks Board facilitated an increase in population to over 20,000 in 2015 through aggressive conservation management [2]. Black rhinoceros (Diceros bicornis) populations declined from several hundred thousand in the early 19th century to ∼65,000 in 1970 and to ∼2,400 by 1995 [1] with subsequent genetic reduction, also due to hunting, land clearances and later poaching [4]. In South Africa, rhinoceros poaching incidents have increased from 13 in 2007 to 1,215 in 2014 [1]. This has occurred despite strict trade bans on rhinoceros products and strict enforcement in recent years.

Missense Mutation in the Ligand-Binding Domain of the Horse Androgen Receptor Gene in a Thoroughbred Family with Inherited 64,XY (SRY+) Disorder of Sex Development.

Disorders of sex development (DSD) have long been documented in domestic animal species including horses. However, there is only a single report of an androgen receptor (AR) mutation causative of such a DSD syndrome in a horse pedigree. Here, we present a new familial AR mutation in horses. A missense mutation (c.2042G>C) at AR exon 4 explains the segregation of the DSD in a Thoroughbred horse pedigree. The mutation, expected to affect the ligand-binding domain of the AR protein, led to complete androgen insensitivity of 64,XY SRY+, testicular DSD individuals. Additionally, the design of a PCR-RFLP technique provided an accurate molecular test for the identification of horses carrying the mutation.

Complete Genome Sequences of Four African Horse Sickness Virus Strains from a Commercial Tetravalent Live Attenuated Vaccine

ABSTRACT This is a report of the complete genome sequences of plaque-selected isolates of each of the four virus strains included in a South African commercial tetravalent African horse sickness attenuated live virus vaccine.