Populations In Southern Africa Research Articles

The African seaforest: a review

Abstract Kelp forests dominate the western and southwestern coastlines of southern Africa. This expansive ecosystem spreads over two very different ecoregions that are of particular interest to researchers due to the complexities of their physical environment. The mid-to-late 1900s saw a proliferation in pioneering research on southern African kelp forests. Since this period (1970–1989), researchers have published comparatively few seminal studies concerning kelp forest ecology and biological functioning. In light of this deficit, this review synthesised pre-existing research on southern African kelp forests, and highlighted key gaps in the research landscape to spark interest and facilitate new studies. Among several others, key research gaps uncovered by this review include kelp carbon sequestration potential and possible contributions to the blue bioeconomy; deeper exploration into the biological functioning and ecological roles of Macrocysis pyrifera and Ecklonia radiata populations in southern Africa; and the impacts of a changing physical environment on these kelp forests. In light of our rapidly changing climate, filling these gaps will be essential in informing conversations around coastal and marine management decisions and policy.

Intraspecific morphological and genetic variation in South African populations of a polystomatid flatworm parasite

The African Clawed Frog Xenopus laevis, a global invader, exhibits a marked phylogeographic divergence among native populations in southern Africa, which seems to enhance its invasive potential. The polystomatid flatworm, Protopolystoma xenopodis, is the frog’s most frequently co-introduced metazoan parasite. In an integrative approach, we utilised morphometrics and molecular markers to assess variation in P. xenopodis in its native range. We measured twelve key morphological characters from 23 flatworms and compared these statistically between flatworms collected from the northern- and southernmost distribution in South Africa. Phylogenetic analyses were based on three concatenated markers, namely 28S and 12S rDNA and COX1, from six flatworms. The combination of five morphological characters, which involve egg size, gut morphology and size of the attachment hooks, differentiated northern and southern populations of P. xenopodis. The multilocus phylogenetic analyses showed a cluster of northern P. xenopodis and two southern lineages with more basal positioning. These findings demonstrate a relatively high level of intraspecific variation in P. xenopodis in its native range. The presented intraspecific variation of P. xenopodis could be potentially informative to trace geographic origin in its non-native range.

Exploring temperature and precipitation changes under future climate change scenarios for black and white rhinoceros populations in Southern Africa

ABSTRACT Climate change is a potential human-induced threat to rhino populations and their habitat. Information on the effects of climate change on rhinoceros species can help manage and develop conservation plans to adapt to these changes. In this study, two climate change scenarios were used to predict temperature and precipitation changes in national parks in southern Africa and the effect those changes would have on black (Diceros bicornis) and white (Ceratotherium simum) rhinoceros populations. The study used the Intergovernmental Panel on Climate Change (IPCC) Representative Concentration Pathways (RCPs) 4.5 and 8.5, atmospheric CO2 concentrations of 650 and 1370 ppm, for the years 2055 and 2085 to explore the temperature and precipitation changes. All spatial information was processed using Geographic Information Systems and statistical analysis. Results show the changing climate will have significant negative impacts on the probability of occurrence of both species. Temperature changes will affect these probabilities more than precipitation changes. All study parks will have zero probability of occurrence for the species throughout their ranges should conditions reach those represented by the RCP 8.5 scenario late in the century. Conservation activities for the rhinoceros should take into consideration the potential for temperature and precipitation changes modelled in this study.

Southern African plants used as soap substitutes; phytochemical, antimicrobial, toxicity and formulation potential

A major proportion of the population in southern Africa relies on medicinal plants, commonly known as soapy plants, for bathing and washing; however, there is limited scientific evidence that validates the effectiveness of southern African soap plants. Therefore, this study aimed to investigate the phytochemistry, antimicrobial activity, and toxicity of plants used in southern Africa as soap substitutes. Thereafter, an effective antimicrobial herbal soap was formulated and assessed for antimicrobial efficacy. Plant selection was based on a comprehensive ethnobotanical literature review that was conducted to gather information on plants used as soap substitutes in southern Africa. A total of 29 plant extracts (26 plant species) were screened for antimicrobial activity against 16 relevant skin pathogens. The minimum inhibition concentration (MIC) assay was used to assess antimicrobial activity. The plant extracts were quantitatively screened for the presence of saponins. Furthermore, the plant extracts were also assessed for toxicity using the brine shrimp lethality assay (BSLA). Calodendrum capense (L.f.) Thunb., Pelargonium peltatum (L.) L'Hér. and Ptaeroxylon obliquum (Thunb.) Radlk. demonstrated notable broad-spectrum activity against most of the tested pathogens. Hermannia cuneifolia Jacq. displayed the highest saponin content (262.41 ± 1.90 mg/g), followed by Sideroxylon inerme L. subsp. inerme (71.34 ± 1.01 mg/ml), Acalypha glabrata Thunb. (70.48 ± 2.05 mg/g), and Noltea africana (L.) Endl. (68.53 ± 2.43 mg/g). Acalypha glabrata, Aloe maculata All., Bauhinia bowkeri Harv., Deinbollia oblongifolia (E. Mey. ex Arn.) Radlk., Ledebouria luteola Jessop., Pouzolzia mixta Sohm, and S. inerme subsp. inerme organic and aqueous extracts demonstrated the lowest toxic effects at 24 and 48 h. Calodendrum capense and Ptaeroxylon obliquum organic extracts were non-toxic at 500 μg/ml, and Pelargonium peltatum displayed low toxicity at a concentration of 125 μg/ml. Calodendrum capense, Pelargonium peltatum and Ptaeroxylon obliquum were selected as the three most favourable plants for soap formulation. Pelargonium peltatum and Calodendrum capense herbal soaps were categorized as first-grade soaps (84 and 80% total fatty matter, respectively). All the tested soaps having plant concentrations of 12.5 mg/ml inhibited all the tested micro-organisms except for Enterobacter cloacae. The findings (phytochemical, antimicrobial, toxicity) herein contribute to the knowledge gaps that exist in the ethnobotanical literature of some southern African soap plants and provide evidence for their potential to be incorporated into soap formulation.

Oral microbiome homogeneity across diverse human groups from southern Africa: first results from southwestern Angola and Zimbabwe

BackgroundWhile the human oral microbiome is known to play an important role in systemic health, its average composition and diversity patterns are still poorly understood. To gain better insights into the general composition of the microbiome on a global scale, the characterization of microbiomes from a broad range of populations, including non-industrialized societies, is needed. Here, we used the portion of non-human reads obtained through an expanded exome capture sequencing approach to characterize the saliva microbiomes of 52 individuals from eight ethnolinguistically diverse southern African populations from Angola (Kuvale, Kwepe, Himba, Tjimba, Kwisi, Twa, !Xun) and Zimbabwe (Tshwa), including foragers, food-producers, and peripatetic groups (low-status communities who provide services to their dominant neighbors).ResultsOur results indicate that neither host genetics nor livelihood seem to influence the oral microbiome profile, with Neisseria, Streptococcus, Prevotella, Rothia, and Porphyromonas being the five most frequent genera in southern African groups, in line with what has been shown for other human populations. However, we found that some Tshwa and Twa individuals display an enrichment of pathogenic genera from the Enterobacteriaceae family (i.e. Enterobacter, Citrobacter, Salmonella) of the Proteobacteria phylum, probably reflecting deficient sanitation and poor health conditions associated with social marginalization.ConclusionsTaken together, our results suggest that socio-economic status, rather than ethnolinguistic affiliation or subsistence mode, is a key factor in shaping the salivary microbial profiles of human populations in southern Africa.

Detection and Characterization of an H9N2 Influenza A Virus in the Egyptian Rousette Bat in Limpopo, South Africa.

In recent years, bats have been shown to host various novel bat-specific influenza viruses, including H17N10 and H18N11 in the Americas and the H9N2 subtype from Africa. Rousettus aegyptiacus (Egyptian Rousette bat) is recognized as a host species for diverse viral agents. This study focused on the molecular surveillance of a maternal colony in Limpopo, South Africa, between 2017-2018. A pan-influenza hemi-nested RT-PCR assay targeting the PB1 gene was established, and influenza A virus RNA was identified from one fecal sample out of 860 samples. Genome segments were recovered using segment-specific amplification combined with standard Sanger sequencing and Illumina unbiased sequencing. The identified influenza A virus was closely related to the H9N2 bat-influenza virus, confirming the circulation of this subtype among Egyptian fruit bat populations in Southern Africa. This bat H9N2 subtype contained amino acid residues associated with transmission and virulence in either mammalian or avian hosts, though it will likely require additional adaptations before spillover.

Protecting HIV service delivery for key populations in southern Africa in the context of the COVID-19 pandemic

The 2025 UNAIDS targets prioritize reaching all subpopulations living with HIV and those at risk for HIV as the only pathway to achieving control of the HIV epidemic. This has brought to the fore the importance of addressing the needs of key marginalized groups and placing such communities at the center of HIV response strategies. However, the COVID-19 pandemic has resulted in a setback in terms of confronting HIV. With this in mind, it is important not only to protect services within HIV responses among key populations, but also to expand such services to meet the UNAIDS 2025 targets. Without this, gains in controlling COVID-19 may be achieved at the expense of losses in controlling the spread of HIV, which had been achieved after sustained and resource-intensive actions.

Stigma reduction is key to improving the HIV care continuum.

Global targets toward ending the HIV epidemic were missed in 2020, and key populations such as transgender women and men who have sex with men (MSM), were often the ones left behind.1 Data are mounting on the substantial HIV inequities faced specifically by key populations in southern Africa. However, few of these studies have disaggregated the data for transgender women from that of MSM, 2 and none have explicitly included genderqueer individuals. Although UNAIDS emphasises the importance of reaching key populations, including MSM and transgender women, to achieve the 90–90–90 goals (ie, 90% of people with HIV being aware of their status, 90% of status-aware people with HIV on antiretroviral treatment [ART], and 90% of people on ART with a suppressed viral load), the data on progress towards these goal among MSM or transgender women and genderqueer individuals are quite scarce.

The implied significance of integrative geographical information systems in sustainable tourism and comprehensive community development in Musina Municipality, South Africa

PurposeThe purpose of the paper was to explore the latent function of geographic information systems (GIS) in sustainable tourism, community-based natural resource management (CBNRM) and local community development in Southern Africa, broadly Africa, and diverse rural areas elsewhere globally. Hence, significantly liaising with data and literature review on the Musina Municipality natural resource management, livelihoods, and tourism development issues in Limpopo Province, South Africa.Design/methodology/approachThe study utilizes a general literature review, document reviews, focus group discussions and field observations to examine the Musina Municipality's rural, environmental and tourism resources management situations along with African and worldwide pertinent implications. The study benchmarks with CBNRM and GIS in sustainable tourism nature within the Musina Municipality.FindingsThe study reveals a fitter dormant-synergetic link among tourism and agrarian (rural) exercises that GIS along a concept of CBNRM can expand within the Municipality. Hence, the study has presented a necessity for a proper and a GIS-unified tourism approach to permit the local communities in Musina Municipality and towards the entire continent.Originality/valueSeveral rural populations in Southern Africa and Africa broadly dwell in low-income areas; Musina Municipality is no exception. Such environs are rich in natural biodiversity, including tourism entities host regions. GIS, sustainable tourism and CBNRM can create a gestalt of local community development projects within such milieus.

'Too many mice make no lining for their nest' - Reasons and effects of parallel governmental structures for disaster risk reduction and climate change adaptation in Southern Africa.

Many African countries face escalating challenges of increasing disaster risk and anticipated impacts of climate change. Although disaster risk reduction (DRR) and climate change adaptation (CCA) are tightly linked and comprising virtually identical practices in vulnerable countries in Southern Africa, research has identified parallel governance structures across the region. This study applied comparative case study research, based on 27 semi-structured interviews, to investigate the reasons for and effects of such parallel structures for DRR and CCA in Botswana, Mozambique, the Seychelles, Tanzania and Zambia. It revealed overwhelmingly negative effects in terms of unclear mandates and leadership, uncoordinated efforts, duplication of efforts, suboptimal use of resources and competition over resources and control. The study identified both external reasons for the parallel structures, in terms of global or international initiatives or incentives, and internal reasons, with regard to the history and quality of the governance structures. Although the identified negative effects are common to a range of complex nexuses, there is a clear distinction with the DRR–CCA nexus comprising virtually indistinguishable practices in Southern Africa. There is, as such, no practical reason for keeping them apart. The parallel structures for DRR and CCA are instead the result of pervasive institutionalisation across the region, driven by coercive, mimetic and normative pressures coming from both within and abroad. Although much point to the difficulties of changing the studied institutional arrangements, these parallel structures for DRR and CCA must be addressed if the populations in Southern Africa are to enjoy safety and sustainable development.

The MIS 5a (~80 ka) Middle Stone Age lithic assemblages from Melikane Rockshelter, Lesotho: Highland adaptation and social fragmentation

Multidisciplinary research suggests that Marine Isotope Stage 5 (~130–74 ka) was an important evolutionary stage in African deep history. Population expansion and growth spurred changes in material culture as well as the exploration of previously unoccupied regions and ecosystems. The archaeological sequence at Melikane Rockshelter (1860 masl) in the Maloti-Drakensberg Mountains of highland Lesotho, southern Africa, stretches from the late Holocene back to sub-stage 5a, ~80 ka. The site's earliest strata represent one of the earliest known examples of a sustained human presence in high mountain systems worldwide. This paper deals with the lithic assemblages from those levels, which are currently the oldest radiometrically dated archaeology in Lesotho and one of the few stratified assemblages of Last Interglacial age in the southern African interior. The results of a typo-technological analysis of the assemblages are presented. They suggest that the afromontane foragers who resided at Melikane employed both blade-focussed and bipolar flaking systems, curated a maintainable toolkit suited to frequent residential moves, and used a hybrid provisioning system adapted to their immediate environment. Comparisons with other late Last Interglacial assemblages across the subcontinent suggest that highland populations at this time were largely disconnected from their lowland counterparts. This implies that as Last Interglacial populations in southern Africa expanded into new environments, they also fragmented, adapting to local conditions rather than adhering to a universal technological system.

Genetic diversity, relatedness and inbreeding of ranched and fragmented Cape buffalo populations in southern Africa.

Wildlife ranching, although not considered a conventional conservation system, provides a sustainable model for wildlife utilization and could be a source of valuable genetic material. However, increased fragmentation and intensive management may threaten the evolutionary potential and conservation value of species. Disease-free Cape buffalo (Syncerus caffer caffer) in southern Africa exist in populations with a variety of histories and management practices. We compared the genetic diversity of buffalo in national parks to private ranches and found that, except for Addo Elephant National Park, genetic diversity was high and statistically equivalent. We found that relatedness and inbreeding levels were not substantially different between ranched populations and those in national parks, indicating that breeding practices likely did not yet influence genetic diversity of buffalo on private ranches in this study. High genetic differentiation between South African protected areas highlighted their fragmented nature. Structure analysis revealed private ranches comprised three gene pools, with origins from Addo Elephant National Park, Kruger National Park and a third, unsampled gene pool. Based on these results, we recommend the Addo population be supplemented with disease-free Graspan and Mokala buffalo (of Kruger origin). We highlight the need for more research to characterize the genetic diversity and composition of ranched wildlife species, in conjunction with wildlife ranchers and conservation authorities, in order to evaluate the implications for management and conservation of these species across different systems.

The potential of Uapaca kirkiana fruit jam for the delivery of Lactobacillus rhamnosus yoba as a probiotic food

Probiotics are important in enhancing food quality, reducing incidences of diarrhoea and promoting good health. A fruit jam is an ideal food to deliver probiotics because it is easy to produce, a good source of sugar, and most rural population consume it. A probiotic jam was developed using an underutilised fruit, U. kirkiana, to benefit the resource-poor population in southern Africa. U. kirkiana fruit is found abundant in most semi-dry rural areas of Zimbabwe. Ripe U. kirkiana fruits were obtained from preferred domesticated trees by households residing in semi-dry rural areas of Zimbabwe. The fruits were pulped by removing seeds, mashing and sieving through an 800 μM sieve. Pectin content of the pulp was determined. A probiotic jam was developed using the formulation 55 % (wt/vol) pulp, 43 % (wt/vol) sugar, 1.5 % (wt/vol) pectin, and 0.5 % (wt/vol) citric acid. The fruit pulp was mixed with sugar in a stainless steel pot and cooked at 110 °C. Citric acid was added and stirred whilst cooking until it reached 55 oBrix. Pectin was added and the jam was continuously stirred until it reached 68 oBrix. The jam was inoculated with 0.25 % L. rhamnosus yoba and left to propagate for 24 hours, while bacterial growth was monitored. The physicochemical and functional properties (pH, total soluble solids, sugars, total titratable acidity, iron content, zinc content, and vitamin C), and L. rhamnosus yoba viability in the probiotic jam was analysed. The probiotic jam had vitamin C, total titratable acidity, total soluble solids, and moisture content of 0.34 ±0.02 mg /100 g FW, 2.2 ± 0.11 g / L FW, 68.5 ± 0.2 % FW, and 34.8 ± 1.2 % FW, respectively; iron and zinc content of 4.13 ± 0.52 mg /100 g FW and 0.36 ± 0.02 mg /100 g FW, respectively; high fructose and sucrose content of 12.84 ± 0.21 g /100 g FW and 24.61 ± 0.12 g /100 g FW, respectively; and a total titratable acidity content of 2.2 g / L at day 0 (after production), 2.37 ± 0.01 g / L FW at day 4, and 2.48 ± 0.02 g / L FW at day 7 of storage (25 °C). The probiotic jam had 6.2 ± 0.2 Log CFU / mL viable cells on point of consumption. U. kirkiana fruit jam can potentially deliver live L. rhamnosus yoba cells as a probiotic food. Key words: Probiotic food, vitamin C, fruit jam, L. rhamnosus yoba, pectin, U. kirkiana fruit, sub-Saharan Africa

Prevalence of metabolic syndrome in sub-Saharan Africa: A systematic review and meta-analysis

Background and aimsThere are rising levels of cardiovascular diseases (CVDs) and diabetes in Sub-Saharan Africa (SSA). Metabolic syndrome (MS) is a precursor of these conditions, but the data on the prevalence of MS in SSA are fragmented. We conducted a systematic review and meta-analysis to estimate the prevalence of MS in SSA and determine the population groups that are most at risk. Methods and resultsWe systematically searched PubMed, Embase and African Journals Online for all published articles reporting MS prevalence in SSA populations. Random effects models were used to calculate the pooled prevalence overall and by major study-level characteristics. A total of 65 studies across fourteen different countries comprising 34,324 healthy participants aged ≥16 years were included in the meta-analysis. The overall prevalence of MS according to the different diagnostic criteria was: IDF: 18.0% (95%CI:13.3–23.3), IDF-ethnic: 16.0% (95%CI:11.3–21.4), JIS: 23.9% (95%CI: 16.5–32.3), NCEP-ATP III: 17.1% (95%CI:12.8–22.0) and WHO: 11.1% (95%CI:5.3–18.9). The prevalence of MS was higher in women than in men, and higher in (semi-)urban than in rural participants. The MS prevalence was highest in Southern Africa, followed by Eastern, Western and Central Africa. Substantial heterogeneity in the prevalence estimates across studies were not explained by major study-level characteristics, while apparent publication biases were likely artefactual. ConclusionsMS is not rare in SSA. The prevalence of MS was highest for women, populations in urban areas, and populations in Southern Africa. Public health intervention efforts are needed to prevent further increases in the burden of MS in the region.

Genetic diversity and relationships among three Southern African Nguni cattle populations

The Nguni cattle breed has distinct populations that are adapted to the different ecological zones of Southern Africa. This study was carried out to assess genetic diversity and establish the relationships among South African (SA), Mozambican (Landim), and Swazi Nguni cattle populations, using 25 microsatellite markers. Genotypic data were generated from deoxyribonucleic acid (DNA) samples of 90 unrelated individuals of the three cattle populations, collected from government conservations and stud herds. DNA profiles of five local beef breeds were used as the reference populations. Most of the 25 microsatellite markers were highly polymorphic across the studied populations, with an overall polymorphic information content (PIC) mean of 0.676. Genetic diversity within populations was high with expected heterozygosity varying from 0.705 ± 0.024 (Landim) to 0.748 ± 0.021 (SA Nguni) and mean number of alleles being highest in the SA Nguni (7.52 ± 0.42). Average observed heterozygosity (0.597 ± 0.046) compared to the expected heterozygosity (0.719 ± 0.022) was lowest for the Swazi Nguni, which also had a high number of Hardy-Weinberg Equilibrium (HWE) deviated loci (13), confirming the relatively high level of inbreeding (0.158 ± 0.058) in that population. Analysis of molecular variance revealed only 9.61% of the total variation between the populations and 90.39% within populations. A short genetic distance (0.299) was observed between Landim and Swazi Nguni, with the SA Nguni (> 0.500) being the most genetically distant population. The distant relationship between SA Nguni and the other two Nguni cattle populations was further confirmed by a principal coordinates analysis. The three Nguni populations clustered independently from each other, despite some evidence of admixture. Therefore, it can be concluded that SA Nguni, Landim, and Swazi Nguni populations in Southern Africa exhibit high levels of genetic diversity and are genetically distant; with the two latter populations being less genetically apart. These results present useful information for the development of strategies for regional management of animal genetic resources, through conservation and sustainable utilisation.

Strong population structure and limited gene flow between Yellow-billed Ducks and Mallards in southern Africa

AbstractSecondary contact and hybridization between recently diverged taxa have been increasing due to anthropogenic changes to the environment. Determining whether secondary contact leads to gene flow between species is important for understanding both the evolutionary consequences of such events (i.e. genetic swamping, speciation reversal, hybrid speciation) and for establishing proper conservation measures. Mallards (Anas platyrhynchos), which natively have a Holarctic distribution, have been introduced nearly worldwide due to game-farm and domestic pet releases. Their expanding range has resulted in secondary contact and increased incidences of hybridization with many closely related Mallard-like ducks that comprise the Mallard complex. Here, we assay molecular diversity for 19 nuclear introns and the mitochondrial DNA for wild Mallards (n = 50) across their Holarctic range and Yellow-billed Ducks (n = 30–75; Anas undulata) from southern Africa to determine population genetic structure and test for evidence of Mallard introgression into Yellow-billed Ducks. While we found limited support for contemporary gene flow across nuclear markers, we provide evidence from mitochondrial DNA that best supports ancient gene flow between Yellow-billed Ducks and Mallards. Yellow-billed Ducks best fit a single population at nuclear markers but show some location-specific mtDNA structure that suggests recent founder or bottleneck events. Although we find that introgression from Mallards into Yellow-billed Duck is limited, Yellow-billed Duck populations should be monitored to determine if expanding feral Mallard populations in southern Africa are increasing introgression.

Effects of a Short Message Service(SMS) Intervention on Reduction of HIV Risk Behaviours and Improving HIV Testing RatesAmong Populationslocated near Roadside Wellness Clinics: A Cluster Randomised Controlled Trial in South Africa, Zimbabwe and Mozambique.

Short Message Service (SMS) offers an innovative method of promoting sexual health to key and vulnerable populations who are users of mobile phones and are at high risk of HIV infection. This cluster randomised control trial tests the effectiveness of a SMS intervention in reducing HIV risk behaviours and improving HIV testing behaviours among truck drivers, sex workers and community residents located near Roadside Wellness Clinics (RWCs)in three southern African countries. The SMS arm received 35 HIV risk reduction and HIV testing SMSs over a 6-month period. The SMS intervention had no significant impact on sexual risk behaviours. However, participants in the SMS arm were more likely to have tested for HIV in the previous 6 months (86.1% vs. 77.7%; AOR 1.71, 95% CI 1.11-2.66). The results indicate that the general SMS intervention, which provide health promoting information, improved HIV testing rates in key and vulnerable populations in southern Africa.

Using species-diagnostic SNPs to detail the distribution and dynamics of hybridized black bass populations in southern Africa

The widespread introduction of Largemouth Bass (Micropterus salmoides) and Florida Bass (M. floridanus) to establish sport fisheries represents a significant conservation concern given their role as apex predators and their ability to alter community diversity and species abundance. In regions like southern Africa, which has both high levels of aquatic endemism and imperilment, limiting the spread of invasive predators is a primary goal of current alien species legislation. Here, we applied two panels of species-diagnostic SNPs for a total of 60 markers to map the distribution of Largemouth Bass, Florida Bass, and their hybrids in 13 southern African water bodies. Using Bayesian clustering algorithms we documented the introgression of Florida Bass alleles across a broad geographic range, from the Cape Floristic region of South Africa to Mozambique. Several populations previously considered pure Largemouth Bass based on mitochondrial DNA sequences were found to consist exclusively of hybrids. Samples collected from Lake Chicamba, which was initially established with pure Largemouth Bass, are now almost exclusively comprised of Florida Bass alleles (89.3 % Florida Bass). The estimated hybrid class of sampled fish (e.g., F1 hybrid, pure Largemouth Bass, pure Florida Bass) showed that with few exceptions, populations were dominated by a single hybrid class. The present work provides enhanced resolution of the distribution and dynamics of Florida Bass, Largemouth Bass, and their hybrids in southern Africa.

Lead Exposure in the Critically Endangered Bearded Vulture (Gypaetus barbatus) Population in Southern Africa

Lead poisoning is an important threat to some raptor species, and the primary source of lead is through the ingestion of carcasses that have been shot with lead, which makes scavengers such as vultures particularly vulnerable. We examined the concentrations of lead in blood and bone tissue samples collected throughout the range of the Bearded Vulture (Gypaetus barbatus) in southern Africa. This population is regionally critically endangered and it is not known to what extent lead poisoning may be a threat. Blood lead levels (0.62 ± 0.81 μg dL−1) from six live birds tested in 2017 indicated background levels of exposure to lead. Similarly, five live birds tested in 2009 using a less sensitive method all had blood lead levels <3 μg dL−1. Bone lead levels (11.79 ± 8.34 μg g−1) from eight birds that had died indicated lead exposure and accumulation over time, suggesting that lead may have contributed to their deaths. These levels of lead may be detrimental to the survival and fecundity of this small and declining population. Recommendations to address this threat include banning hunting and culling with lead ammunition, which is the most likely source of this pollutant. Such actions may reduce the population's susceptibility to other threats, which may be compounded by high lead levels, and help ensure the success of planned reintroduction programs.

Different Selected Mechanisms Attenuated the Inhibitory Interaction of KIR2DL1 with C2+ HLA-C in Two Indigenous Human Populations in Southern Africa.

The functions of human NK cells in defense against pathogens and placental development during reproduction are modulated by interactions of killer cell Ig-like receptors (KIRs) with HLA-A, -B and -C class I ligands. Both receptors and ligands are highly polymorphic and exhibit extensive differences between human populations. Indigenous to southern Africa are the KhoeSan, the most ancient group of modern human populations, who have highest genomic diversity worldwide. We studied two KhoeSan populations, the Nama pastoralists and the ≠Khomani San hunter-gatherers. Comprehensive next-generation sequence analysis of HLA-A, -B, and -C and all KIR genes identified 248 different KIR and 137 HLA class I, which assort into ∼200 haplotypes for each gene family. All 74 Nama and 78 ≠Khomani San studied have different genotypes. Numerous novel KIR alleles were identified, including three arising by intergenic recombination. On average, KhoeSan individuals have seven to eight pairs of interacting KIR and HLA class I ligands, the highest diversity and divergence of polymorphic NK cell receptors and ligands observed to date. In this context of high genetic diversity, both the Nama and the ≠Khomani San have an unusually conserved, centromeric KIR haplotype that has arisen to high frequency and is different in the two KhoeSan populations. Distinguishing these haplotypes are independent mutations in KIR2DL1, which both prevent KIR2DL1 from functioning as an inhibitory receptor for C2+ HLA-C. The relatively high frequency of C2+ HLA-C in the Nama and the ≠Khomani San appears to have led to natural selection against strong inhibitory C2-specific KIR.