付記する学位プログラム名: 霊長類学・ワイルドライフサイエンス・リーディング大学院 / 京都大学 / 0048 / 新制・課程博士 / 博士(理学) / 甲第22635号 / 理博第4624号 / 新制||理||1664(附属図書館) / 京都大学大学院理学研究科生物科学専攻 / (主査)准教授 足立 幾磨, 准教授 後藤 幸織, 教授 濱田 穣 / 学位規則第4条第1項該当 / Doctor of Science / Kyoto University / DGAM

Up to 87% of the world’s wetlands have been destroyed, considerably reducing ecosystem services these wetlands once provided. More recently, many wetlands are being restored in an attempt to regain their ecosystem service. This study seeks to determine the effects of restored wetlands on local bat habitat use. Bat activity was found to be significantly higher around the wetlands when compared to distant grassy fields; however, no significant difference was found among the restored wetlands and a remote cattle farm containing multiple water features. Geospatial models of bat distribution and bat foraging were produced using machine learning that showed higher habitat suitability and foraging activity around restored wetlands than around distant grassy fields, suggesting that wetlands provide vital habitat for insectivorous bats. This study demonstrates that restored wetlands promote bat activity and bat foraging, and restoring wetlands may be a useful means of increasing natural pest control over nearby farmlands.

Reproductive isolation is an essential stage in speciation. In Ascomycetes, the ubiquitous distribution of many species suggests that sympatric speciation through assertive mating should be an important factor. The MAT locus and the pheromone/receptor system could both potentially contribute to the development of such sexual isolation. Alterations at the MAT loci could lead to distinct reproductive habits or a change in mating system, both of which can reduce gene-flow between species. However, if deliberate pre-mating sexual preferences exist, they are more likely to be determined by the pheromone/receptor system. This study of Fusarium reproductive genes, and comparisons with other Ascomycetes, has yielded numerous interesting findings regarding the evolution of these mate-recognition mechanisms and the implications thereof. The G. fujikuroi and F. graminearum species complexes have offered an interesting comparison between heterothallic and homothallic MAT locus evolution. The value of comparative sequence analysis has been demonstrated in the discovery of a previously unknown gene, MAT1-2-3, which may be specific to members of the Order Hypocreales. While all MAT genes share similar regulatory elements, this is the first report of evidence that a transition to homothallism can be accompanied by the recruitment of distinct elements that could facilitate alternate expression of MAT genes. The MAT genes are also highly divergent between Fusarium spp., largely due to relaxed selective constraint, particularly in homothallic species. However, inter-specific gene-flow could curb MAT gene divergence among homothallic species. Despite strong reproductive barriers in the G. fujikuroi complex, the F. sacchari MAT1-1 sequence appears to have been acquired through lateral transfer from a distant relative. Analytical analysis of the MAT locus novelties reported here, including the new MAT gene, will be necessary to determine their biological significance. To investigate the extent of pheromone diversity in the Ascomycetes, and to gain clues as to its biological importance, pheromone peptides from seventy ascomycete species were compared. A number of reproductively incompatible species, such as those in the G. fujikuroi complex, share identical pheromones; which implies that another mechanism must be responsible for the observed reproductive barriers. However, on the whole, pheromones are highly divergent among species. Both adaptive and non-adaptive evolution could have contributed to this pattern. In fact the structure of the á-class pheromone precursor gene, which consists of multiple repeats of the pheromone module, could facilitate rapid diversification through “birth-and-death” evolution. Within species, selection maintains pheromone peptides, implying that much of the inter-specific variation is functionally relevant. This further suggests that pheromone evolution could contribute to the generation of reproductive isolation between species. The most general trend in the findings of this study is that ascomycete reproductive genes are highly divergent. This is in agreement with findings in other Kingdoms. A number of evolutionary forces are probably involved but weaker selective constraint, resulting from the fact that reproduction is not essential in these fungi, appears to be a common factor. This reproductive gene variability could be directly linked to speciation and, therefore, the great diversity in Ascomycetes. Additional information on the appendices is available on a CD, stored at the Merensky Library on Level 3 / Dissertation (MSc)--University of Pretoria, 2011. / Genetics / Unrestricted

Tree species belonging to the genus Acacia have a significant impact ecologically and economically in southern Africa. Together with the African baobab, these trees are recognized as icons of the African landscape. They are widely distributed in this area and extensively used by local communities as sources of energy, stock feed, medical remedies and building material. There is still a substantial lack of knowledge regarding the ecological association between these plants and other living organisms such as fungi. This is, however, not new to the African continent where fungi are generally poorly studied and collected, and it is envisaged that many new fungal species will be discovered as scientists focus their efforts more on this geographical niche. An example of the lack of knowledge on the fungal biodiversity in Africa is reflected in the limited reports of members of the Botryosphaeriaceae, described to date from Acacia spp.. A review on phytopathogens in South Africa by Crous et al. (2000) indicated no records of the Botryosphaeriaceae associated with native Acacia spp. Despite the importance of many species within the Botryosphaeriaceae as pathogens, knowledge about the true diversity and taxonomy of species in this family is limited, especially where native plant communities are concerned. This dissertation attempts to contribute to knowledge on the associations between members of the Botryosphaeriaceae and indigenous Acacia trees in southern Africa, and the possible role they may play in diseases of these trees. Chapter 1 represents a literature review that focuses on fungi previously associated with Acacia spp. on the African continent. Information provided in this chapter refers to available reports on pathogens and saprophytes occurring on Acacia spp. that are both native and nonnative to Africa. Special reference is made to those occurring in southern Africa. Due to the concern of the introduction of new pathogens in areas where native and non-native plants are co-existing, emphises is also placed on the possibility of pathogen-host jumps between native and non-native Acacia spp. The potential threat they might pose to the future biosecurity of these important trees is discussed. Acacia mellifera, also known as the blackthorn, is one of the native African Acacia spp. that has been extensively studied. This tree is threatened by a serious die-back disease with symptoms similar to the die-back typically caused by members of the Botryosphaeriaceae. In an effort to understand the association of the Botryosphaeriaceae with native Acacia spp. in southern Africa, a study was undertaken to search for the presence of these fungi on especially A. mellifera in Namibia and the Pretoria area in South Africa. Other Acacia spp. were also sampled in cases where they were present in the same areas as A. mellifera. These results are presented in chapter 2. In a previous study, the fungal diversity of native trees and plant species in the Northern Cape Province of South Africa was studied. This resulted in the isolation of a number of fungi that resembled the morphological characteristics of the Botryosphaeriaceae. In chapter 3, these fungi were further identified to species level based on morphological and phylogenetic characteristics. In chapter 4 an attempt was made to compare the Botryosphaeriaceae that are associated with important native trees with those occurring on non-native trees. To accomplish this, a pilot study was done to investigate the presence of the Botryosphaeriaceae on A. mearnsii in the Gauteng Province of South Africa. Results from chapters 2 and 3 on native Acacia spp. from Namibia and South Africa served as the bases of comparison for this chapter. Results of previous studies that investigated diseases of plantation grown A. mearnsii were also included for comparison. Lastly, a summary is included to review the results of this study and also the significance and impact these results made, not only on the taxonomy of the Botryosphaeriaceae, but also understanding the fungal biodiversity of indigenous tree species in southern Africa. To date, this is the most extensive study of the Botryosphaeriaceae associated with native African Acacia spp. and it is also the first study that resulted in the describtion of so many new species in this group of fungi from a single host. Results from this study indicated that there is a significantly greater diversity in the Botryosphaeriaceae associated with native Acacia spp. in southern Africa than was previously thought. This dissertation attempts to form the basis for future studies to finally understand the interactions between the Botryosphaeriaceae and their native hosts as well as their role and threat as pathogens to indigenous and economically important plants. Copyright / Dissertation (MSc)--University of Pretoria, 2009. / Microbiology and Plant Pathology / unrestricted

English: Common warthogs (Phacochoerus africanus) and bushpigs (Potamochoerus larvatus), were experimentally infected with classical swine fever virus (CSFv) following the diagnosis of classical swine fever (CSF) subtype 2.1 in 2005 in domestic pigs in South Africa. At that time, no data regarding their susceptibility or the potential lesions in these wild suids were available. Seven sub-adult warthogs and six bushpigs were captured, taken to the high containment facilities of the Transboundary Animal Diseases Programme of the Agriculture Research Council (ARC) - Onderstepoort Veterinary Research Institute, and infected intranasally with the South African isolate. In each experiment, two in-contact control animals of the same species verified intraspecies transmission, while two domestic pigs were used to demonstrate virus virulence and viability. Surviving animals were euthanized 44 days post infection. Formalin-fixed tissue samples collected from all experimental animals were evaluated for histological lesions. The warthogs, which remained clinically normal throughout the study, developed histological lesions that were inconsistently present and sometimes subtle. Three warthogs, including one in-contact control, developed distinct perivascular lymphoplasmacytic cuffing in their brains. Subtle lesions included scant lymphoplasmacytic infiltration of various organs, occasionally accompanied by perivascular cuffing. In contrast, the bushpigs developed overt clinical signs similar to CSF in domestic pigs. Four animals out of six, including two in-contact controls, died or were euthanized during the trial. On post mortem examination, intestinal necrosis and ulceration, purulent rhinitis and pneumonia were present. Acutely affected animals developed lymphoid necrosis and depletion whilst surviving individuals showed perivascular lymphoplasmacytic cuffing in multiple organs. Immunohistochemical demonstration of CSFv antigen using a commercially available mouse monoclonal antibody, WH303, revealed intense, widespread labelling in most tissues of all the warthogs and bushpigs as well as the four domestic pigs used as controls during the trial. A wide range of cell types and tissues reacted with the antibody. These included: mononuclear cells (monocyte-macrophages, lymphocytes and plasma cells), follicular reticular cells, epithelial cells, vascular endothelial cells, mesothelial cells, smooth muscle cells and fibroblasts. Tissues that were labelled included tonsil, lymph nodes, spleen, third eyelid, adrenal gland, urinary bladder, skin, liver, kidney, lung, certain cells within central nervous tissue like the choroid plexus, various parts of the gastro-intestinal tract as well as glandular tissue like the pancreas and salivary gland. The tonsils were the most consistently labelled tissue, while no labelling was noted in myocytes of skeletal or cardiac muscle. From the present work, it was concluded that these wild Suidae are susceptible to CSFv and intra-species transmission under experimental conditions can occur. / Afrikaans: Wilde Afrika varke, nl. vlakvarke (Phacocoerus africanus) en bosvarke (Potamochoerus larvatus) was eksperimenteel infekteer met europese varkpes virus nadat die siekte in kommersiële mak varke diagnoseer is in 2005 (dit was tipeer as subtipe 2.1). Geen inligiting oor die vatbaarheid of potensiële letsels weens europese varkpes infeksie in hierdie wilde varke was beskikbaar nie. Sewe wilde onvolwasse vlakvarke en ses bosvarke is gevang, na die isolasie eenheid van die Onderstepoort Veterinêre Instituut se oor-grens siekte afdeling geneem en intranasal geïnfekteer met die Suid-Afrikaanse isolaat van 2005. Twee in-kontak kontrole diere van dieselfde spesie is gebruik in elke eksperiment om intra-spesie oordraging vas te stel en twee mak varke om virus lewensvatbaarheid en virulensie te demonstreer. Oorlewende diere is uitgesit na 44 dae. Formalien gefikseerde weefsel monsters is versamel van hulle, sowel as van diere wat uitgesit is tydens die eksperiment. Die vlakvarke was klinies normal regdeur die eksperiment, maar het wel histologiese letsels ontwikkel wat subtiel was en ook nie altyd teenwoordig in alle gevalle nie. Drie vlakvarke, waarvan een ‘n in-kontak dier was, het prominente limfo-plasmasitiese perivaskulêre flensing in hul breine ontwikkel. Subtiele letsels het klein hoeveelhede limfoplasmasitiese infiltrasies in verskeie organe en somtyds perivaskulêre flensing ingesluit. In teenstelling, het die bosvarke uitgesproke kliniese tekens soortgelyk aan Europese varkpes in mak varke, ontwikkel. Vier uit die ses diere, insluitend twee in-kontak diere is dood of uitgesit tydens die eksperiment. Met nadoodse ondersoek is daar intestinale nekrose en ulserasie, purulente rinitis en pneumonie gevind. Diere wat dood is, het limfoïede nekrose en limfoïede uitputting getoon, terwyl die oorlewende bosvarke perivaskulêre flensing met limfo-plasma selle in verskeie organe ontwikkel het. Immunohistochemiese demonstrasie van Europese varkpes virus antigen deur gebruik van ‘n kommersieël beskikbare muis monoklonale teenligaam, WH303, het duidelike wydverspreide kleuring in meeste weefsel van die die vlakvarke, bosvarke en mak varke getoon. ‘n Wye reeks van weefsel en sel tipes het met die teenliggam reageer naamlik: mononukliêre selle (monosietmakrofage en limfo-plasma selle), follikulêre retikulêre selle, epiteel, vaskulêre endoteel, mesoteel, gladde spier selle en fibroblaste. Weefsel wat gemerk is met die teenliggaam het ingesluit: mangels, limfknope, milt, derde ooglid, adrenaal klier, urienblaas, vel, lewer, nier, long, sekere selle in die sentrale senuwee stelsel, soos die koroïed pleksus, verskeie dele van die gastro-intestinale stelsel sowel as klier weefsel soos die pankreas en speekselklier. Die mangels was die mees konsekwent gemerkte weefsel, terwyl geen kleuring gevind is in miosiete van skelet of hartspier nie. Uit hierdie werk kon daar afgelei word dat vlakvarke en bosvarke vatbaar is vir Europese varkpes en dat intra-spesie oordraging plaasvind onder eksperimentele omstandighede. / Dissertation (MMedVet)--University of Pretoria, 2011. / Paraclinical Sciences / Unrestricted

Between 1970 and 1975 Natal Parks Board hel .icopter counts of waterbuck ( Kobus ellipsiprymnus) in the Umfolozi Game Reserve (UGR) declined from 1 098 to 494. The purpose of this project was to study the ecology of waterbuck with an emphasis on population regulating mechanisms, so that the reality and significance of this decline could be assessed. Density estimates for 1976-1977 were over twice the 1976 helicopter count of 319, but the population was confirmed to be declining. The ecological density of waterbuck represented 11,9 per cent of the metabolic biomass of grazers, which compared well with data from other areas. However, the other species' proportionate contributions to biomass were far from optimal, with an excess of short grass feeders. High juvenile mortality (80,7 per cent), attributable mainly to severe tick (Rhipicephalus appendiculatus) infestations, was the principal cause of the present decline. These severe infestations were probably symptomatic of poor condition of the whole waterbuck population, which meant that the ultimate cause of juvenile mortality lay elsewhere. The hypothesis that the waterbuck population was in a stressed condition was supported by their habitat utilization patterns, their feeding ecology and aspects of their behaviour. The dynamics of interspecific associations suggested that the primary habitat of Waterbuck was that now occupied by nyala (Tragelaphus angasi) and what had been recorded were the results of competition pushing waterbuck into an unfavourable habitat. Feeding studies indicated that nutritious food for herbivores represented a limited resource in UGR during winter, for which waterbuck may be largely outcompeted and that nyala and impala ( Aepyceros melampus) were the rnain competitors . Interspecific competition was the probable ultimate cause of the decline of waterbuck in UGR. It was recommended that the numbers of nyala and impala be reduced and that this action be integrated into a more precise management plan for UGR than exists at present. / Thesis (DSc)--University of Pretoria, 1978. / gm2014 / Zoology and Entomology / unrestricted

The aim of this study was to determine the species composition of questing ixodid ticks on the vegetation in intensive breeding enclosures for sable antelopes (Hippotragus niger), on which strategic tick control is practiced, and to compare it with that of questing ixodid ticks in a multi-species herbivore enclosure surrounding the breeding enclosures, and where no tick control is practiced. A total of eight ixodid tick species were collected namely, Amblyomma hebraeum, Amblyomma marmoreum, Haemaphysalis elliptica, Rhipicephalus appendiculatus, Rhipicephalus decoloratus, Rhipicephalus evertsi evertsi, Rhipicephalus simus and Rhipicephalus zambeziensis. A. marmoreum was only collected in the intensive breeding enclosures and H. elliptica only in the multiple herbivore species enclosure, whilst the remaining tick species were collected in both enclosures. The study was also designed to determine the abundance, seasonal abundance and proportion of ixodid tick larvae collected in the sable antelope breeding enclosures as well as in the multi-species herbivore enclosure and to compare the population dynamics of tick species in the respective enclosures with particular emphasis on R. decoloratus. R. decoloratus accounted for 65.4% of the total number ticks collected in the sable enclosures, whilst it represented only 24.3% of the total number of ticks collected in the multi-species herbivore camp. R. decoloratus was more abundant than A. hebraeum and R. appendiculatus in the woodlands of the sable antelope enclosures whilst R. decoloratus and R. evertsi evertsi were more abundant in grassland habitats of the sable antelope enclosures than both A. hebraeum and R. appendiculatus. R. decoloratus larvae were collected throughout the year with peak collections in November 2012 and between October and December 2013 in the sable breeding enclosures, and in April and May 2012 and February and April 2013 in the multi-species herbivore enclosure. The numbers of R. decoloratus larvae collected in the sable breeding enclosures increased significantly during the study period (p≤0.020). / Dissertation (MSc)--University of Pretoria, 2014. / gm2014 / Veterinary Tropical Diseases / unrestricted

Background: Neutrophil extracellular traps (NETs) constitute a network of chromatin fibres containing histone and antimicrobial peptides that are released by activated neutrophils. NETs protect the host against infection by trapping and facilitating phagocytosis of potentially harmful pathogens. Objectives: The aim of the current study was to investigate the effects cigarette smoke condensate (CSC) on phorbol-ester (PMA)-mediated NETosis in vitro, as well as the effects of cigarette. Methods: Isolated human blood neutrophils were exposed to PMA (6.25 ng/ml) in the presence or absence of CSC (40-80 μg/ml) for 90 min at 37oC. Alternatively neutrophils of non-smokers and smokers were activated with PMA (6.25 ng/ml) for 90 min at 37oC. NET formation was measured using a spectrofluorimetric procedure to detect extracellular DNA and fluorescence microscopy was used to visualize nets. Oxygen consumption by PMA-activated neutrophils was measured using an oxygen sensitive electrode. Cotinine levels were measured in smokers and non-smokers for objective confirmation of smoking status Results: Activation of neutrophils with PMA was associated with induction of NETosis that was significantly attenuated in the presence of CSC (40 and 80 μg/ml), with mean fluorescence intensities of 65% and 66% of that observed with untreated cells, respectively, and confirmed by fluorescence microscopy. The rate and magnitude of oxygen consumption by activated neutrophils pre-treated with CSC (80 μg/ml) was significantly less than that observed with untreated cells (73% of the control system), indicative of decreased production of reactive oxidant species in the presence of CSC. When comparing smokers and non- smokers, neutrophils from smokers showed a decrease in both oxygen consumption and the number of NET-forming cells consistent with attenuation of NET formation due to inhalation of cigarette smoke. Conclusion: The inhibition of NETosis observed in the presence of CSC and CS (in smokers) correlated with attenuation of oxygen consumption by PMA-activated neutrophils suggesting a mechanistic relationship between these events. Smoking-related attenuation of NETosis may impair host immune responses and increase the risk of respiratory infections, in vivo. / Dissertation (MSc)--University of Pretoria, 2016. / Immunology / MSc / Unrestricted

Bats inhabiting arid, subtropical environments face diverse challenges related to energy and water balance. First, they may have to conserve water and energy during cool, dry winters when water is scarce and insect availability reduced. Second, during hot summers when air temperature may routinely exceed body temperature, bats may need to avoid both hyperthermia and dehydration. A common response to the energetically challenging winter period in temperate, subtropical and tropical species is heterothermy (i.e. torpor and hibernation). Despite evidence suggesting that heterothermy is of major significance in the energy balance of tropical and subtropical bats, its occurrence in southern African species especially those in semi-arid subtropical regions have received relatively little attention. Moreover, the physiological and thermoregulatory responses of bats to high air temperatures (Ta) are relatively poorly known. The goal of my project was to investigate various seasonal physiological challenges imposed on bats in an arid, sub-tropical climate. I investigated the occurrence of winter heterothermy in Nycteris thebaica (Nycteridae) in the Limpopo Valley. Skin temperatures (Tskin) were measured using temperature-sensitive transmitters, and roost temperatures (Troost) were recorded using miniature temperature loggers. N. thebaica used multiple roosting sites, including a hollow baobab tree (Adansonia digitata) and several caves, and exhibited only moderate heterothermy. Tskin was maintained around normothermic levels, with differences of 3-9°C (7.5±1.7°C) between overall maximum and minimum Tbs. A minimum Tskin of 28.4°C occurred at Troost = 23.8°C, and patterns of thermoregulation did not appear to be influenced by prevailing weather conditions. Roost temperatures did not decrease below 10°C, and averaged 21.2±2.8°C and 23.3±2.9°C respectively. The lack of pronounced heterothermy in N. thebaica is surprising, particularly in view of the daily torpor cycles observed in many insectivorous bat species. I also investigated the physiological responses of three sympatric bat species during summer using an open-flow respirometry system to measure resting metabolic rates (RMR) and evaporative water loss (EWL) over a range of Tas ~ 10-42°C, with body temperatures (Tb) simultaneously recorded via temperature-sensitive passive integrated transponder (PIT) tags. Basal metabolic rates for Nycteris thebaica and Taphozous mauritianus were 8.9±2.7mW.g-1 and 6.6±2.2mW.g-1 respectively, falling within the 95% prediction intervals for bat BMR, whereas the value for Sauromys petrophilus (3.4±0.6mW.g-1) fell below the lower 95% prediction interval. Maximum EWL for N. thebaica, T. mauritianus and S. petrophilus were 18.6±2.1mg.g-1.h-1 (Ta=39.4°C), 14.7±3.1mg.g-1.h-1 (Ta=41.9°C) and 23.7±7.4mg.g-1.h-1 (Ta=41.7°C) respectively. Maximum individual Tbs recorded were 46.5°C in N. thebaica (Ta=39.3°C), 44.9°C in T. mauritianus (Ta=41.8°C) and 46.5°C in S. petrophilus (Ta=41.7°C). Overall, I found that N. thebaica was the least heat tolerant species, with T. mauritianus and S. petrophilus being more heat tolerant. In the face of climate change, heat tolerance together with specific thermal properties of a given roost may play a major role in the ability of a species to persist in a hot, arid environment. / Dissertation (MSc)--University of Pretoria, 2012. / Zoology and Entomology / unrestricted

PhD (Botany) / Department of Botany / Cycads are regarded as the oldest living seed plants on earth and they have existed for about 300 million years. Ever since the awareness of the existence of this plant group, they have been facing high extinction risk. Currently they are referred to as the most threatened plant group in the world. Many ecological and anthropological forces are promoting extinction crisis of this taxonomic group. Africa is one of the centres of diversity of this plant group with 70% of the total number of the taxa in this group in Africa found in South Africa. Also South Africa is one of the global hotspots for cycads and it contains the third largest number of cycads after Australia and Mexico. Studies have revealed that there have been high threats and extinction risks among the cycad taxa in South Africa. The Soutpansberg Mountain is a major biodiversity hotspot in Limpopo Province in South Africa with high level of flora and fauna taxa. About 3000 vascular plants species are represented on this mountain. Biodiversity on this mountain has been under threat in recent times and there is need to investigate how cycads are facing risk on this mountain. The main focus of this study is to look at the extinction pattern in South African cycads and cycads endemic to Soupandberg Mountain in Limpopo Province in South Africa. v The first objective evaluated all African cycads over a decade using IUCN red list. Data from IUCN 2014 version was used to calculate the percentages of African cycads in each IUCN categories. The results were compared with those presented by Donaldson 2003. They showed that there have been significant decline and increase in extinction of African cycads over this period. It was also discovered that majority of this extinction crisis were trending in South Africa. The second objective used the IUCN red list to evaluate extinction pattern in South African cycads. The percentages of IUCN threat categories of South African cycads was calculated using IUCN red list. ArcGIS was used to construct distribution map for threatened and extinct South African cycads. The study revealed that the proportion of historically Extinct and Critically Endangered cycads is higher in Limpopo, KwaZulu-Natal and Mpumalanga than the rest of the provinces in South Africa. The third objective of this research investigated extinction pattern of Encephalartos transvenosus Stapf & Burtt Davy (Modjadji cycad) on Soutpansberg Mountain. Indigenous knowledge and population ecology approaches were used to determine current threats Modjadji cycads are facing on Soutpansberg Mountain. The results showed that anthropogenic activities have caused a substantial decline of one important unprotected population of this species on Soutpansberg Mountain. / NRF