Genetic characterization and phylogenetic position of Echinococcus felidis (Cestoda: Taeniidae) from the African lion

Echinococcus felidis had been described in 1937 from African lions, but was later included in Echinococcus granulosus as a subspecies or a strain. In the absence of any genetic characterization, most previous records of this taxon from a variety of large African mammals remained unconfirmed due to the lack of diagnostic criteria and the possible confusion with the sympatric E. granulosus sensu stricto, Echinococcus ortleppi and Echinococcus canadensis. In this study, we obtained taeniid eggs from lion feces in Uganda and amplified DNA from individual eggs. Mitochondrial and nuclear DNA sequences showed similarities with those of other Echinococcus spp., but high values of percentage divergence of mitochondrial genes indicated the presence of a distinct species. In a second step, we compared this material with the preserved specimens of adult E. granulosus felidis, which had been identified morphologically approximately 40 years ago in South Africa. All DNA fragments (<200 bp) that could be amplified from the adults showed 100% similarity with the Ugandan material. In the phylogenetic tree of Echinococcus which was constructed from the mitochondrial genes, E. felidis is positioned as a sister taxon of E. granulosus sensu stricto. The data obtained will facilitate the development of diagnostic tools necessary to study the epidemiology of this enigmatic parasite.     

Lost populations and preserving genetic diversity in the lion Panthera leo: Implications for its ex situ conservation

Two of the eight recognized lion subspecies, North African Barbary lion (Panthera leo leo) and South African Cape lion (Panthera leo melanochaita), have become extinct in the wild in the last 150 years. Based on sequences of mitochondrial DNA (mtDNA) control region (HVR1) extracted from museum specimens of four Barbary and one Cape lion, the former was probably a distinct population characterized by an invariable, unique mtDNA haplotype, whilst the latter was likely a part of the extant southern African lion population. Extinction of the Barbary line, which may still be found in “generic” zoo lions, would further erode lion genetic diversity. Therefore, appropriate management of such animals is important for maintaining the overall genetic diversity of the species. The mtDNA haplotype unique to the Barbary lion, in combination with the small size of the HVR1 analyzed (c. 130 bp), makes it possible and cost-effective to identify unlabelled Barbary specimens kept in museums and “generic” captive lions that may carry the Barbary line. An initial study of five samples from the lion collection of the King of Morocco, tested using this method, shows that they are not maternally Barbary.     

Holocene distribution and extinction of the moose (Alces alces, Cervidae) in Central Europe

Moose (Alces alces L.) were among the first large mammals to recolonize Central Europe after the last glaciation. Already during the Allerød they established themselves in most parts of the area. In the early Holocene their distribution range extended from the Pyrenees to Denmark and from Austria to Great Britain and also covered eastern Central Europe where they still occur today. In the Preboreal, the moose slowly vanished from the southwestern parts of its distribution range, leading to its extinction in France and, later, in England. During the Atlantic period, the moose died out in large parts of Denmark and population densities apparently decreased in the rest of Central Europe as well. Around the birth of Christ only relict populations were left in western Central Europe, which finally became extinct in early medieval times. In Thuringia and in the region northeast of the river Elbe as well as in central Poland, some stocks persisted until the high and late Middle Ages. The causes of the gradual extinction in Central Europe during the Holocene are complex. Changes in vegetation, climate and sea-level, the increasing fragmentation of habitat through human activities and hunting were, at different times, important factors. In the recent past, however, moose have repeatedly migrated from the east towards the west. The development of its distribution range since the end of the Second World War as well as experiences with Scandinavian populations show that moose are able to thrive in close proximity to humans and that a future expansion of its distribution range towards the west seems possible.     

Past, present and future of hemophilia: a narrative review

ABSTRACT: Over the past forty years the availability of coagulation factor replacement therapy has greatly contributed to the improved care of people with hemophilia. Following the blood-borne viral infections in the late 1970s and early 1980, caused by coagulation factor concentrates manufactured using non-virally inactivated pooled plasma, the need for safer treatment became crucial to the hemophilia community. The introduction of virus inactivated plasma-derived coagulation factors and then of recombinant products has revolutionized the care of these people. These therapeutic weapons have improved their quality of life and that of their families and permitted home treatment, i.e., factor replacement therapy at regular intervals in order to prevent both bleeding and the resultant joint damage (i.e. primary prophylaxis). Accordingly, a near normal lifestyle and life-expectancy have been achieved. The main current problem in hemophilia is the onset of alloantibodies inactivating the infused coagulation factor, even though immune tolerance regimens based on long-term daily injections of large dosages of coagulation factors are able to eradicate inhibitors in approximately two-thirds of affected patients. In addition availability of products that bypass the intrinsic coagulation defects have dramatically improved the management of this complication. The major challenges of current treatment regimens, such the short half life of hemophilia therapeutics with need for frequent intravenous injections, encourage the current efforts to produce coagulation factors with more prolonged bioavailability. Finally, intensive research is devoted to gene transfer therapy, the only way to ultimately obtain cure in hemophilia.     

Arabia–Eurasia collision and the forcing of mid-Cenozoic global cooling

The end of the Eocene greenhouse world was the most dramatic phase in the long-term cooling trend of the Cenozoic Era. Here we show that the Arabia–Eurasia collision and the closure of the Tethys ocean gateway began in the Late Eocene at ~ 35 Ma, up to 25 million years earlier than in many reconstructions. We suggest that global cooling was forced by processes associated with the initial collision that reduced atmospheric CO₂. These are: 1) waning volcanism across southwest Asia; 2) increased organic carbon storage in Paratethyan basins (e.g. Black Sea and South Caspian); 3) increased silicate weathering in the collision zone and, 4) a shift towards modern patterns of ocean currents, associated with increased vigour in circulation and organic productivity.     

<Emphasis Type="Italic">Fusarium</Emphasis> toxins of the scirpentriol subgroup: a review

Scirpentriol and its seven acetylated derivatives comprise a family of type-A trichothecene toxins produced by several species of Fusarium fungi. Out of this group 4,15-diacetoxyscirpenol has attracted most attention. It elicits toxic responses in several species and was detected in a variety of substrates. Out of the three possible monoacetylated derivatives 15-monoacetoxyscirpenol and the parent alcohol scirpentriol received some attention, whereas the remaining members of the family were mentioned in few reports. The present review deals with the structure, biosynthesis, analysis and toxicity of scirpentriol toxins. Formation by Fusarium species as well as culture conditions used for toxigenicity studies are reviewed; data about the natural occurrence of scirpentriol toxins in different cereal types, cereal associated products as well as in non-grain matrices including potato and soya bean are reported. Basing on literature reports about the toxicity of scirpentriol toxins an attempt is made to summarise the state of knowledge for risk evaluation for human and animal health.     

Molecular genetic variation across the southern and eastern geographic ranges of the African lion, <Emphasis Type="Italic">Panthera leo</Emphasis>

We examined sequence variation in the mitochondrial cytochrome b and NADH dehydrogenase subunit 5 genes (2,360 bp total) for 26 lions from eleven locations throughout sub-Saharan Africa. Six distinct haplotypes were observed in the combined sequences, forming two clades: the eastern and the western savannas. The Uganda-Western Kenya haplotype grouped at a basal position with the eastern clade of lions from Tsavo south to the Transvaal and Natal regions. The phylogenetic position of the haplotype from Sabi Sands in the southern part of Kruger National Park remained poorly resolved. The haplotypes found in Namibia and Botswana formed the western clade. The modest genetic variation documented here argues against taxonomic distinctions among living African lions.     

Benthic foraminifera across the Cretaceous–Tertiary (K–T) boundary: a review

The response of the Earth’s biota to global change is of fundamental interest to paleontologists, but patterns of change in paleontologic data are also of interest to a wider spectrum of Earth scientists in that those patterns are of great significance in constraining hypotheses that attempt to explain physical changes in the Earth’s environment. The Cretaceous–Tertiary (K–T) boundary is a case in point. Some paleontologists have criticized the bolide impact hypothesis, not because they deny the impact but because the proposed effects of that impact do not always conform to the available paleontological data. Benthic foraminifera are of particular interest in this context because it has been suggested for over 20 years that shallow-water benthic foraminifera were affected more severely than deep-water benthic foraminifera by events at the K–T boundary. This observation adds to the fact of planktonic foraminiferal extinction and indicates that K–T boundary environmental effects were largely restricted to shallow waters. In this paper I review all published works on smaller benthic foraminifera at the K–T boundary and conclude the following. (1) Shallow-water benthic foraminifera were not more severely affected than deeper dwelling species. True extinction, as opposed to local extinction and/or mass mortality, is generally quite low no matter what the water depth. (2) The data are not sufficient in quality, quantity and geographic range to conclude that there is a latitudinal pattern of extinction. (3) In general, biotic changes (such as they are) begin before the boundary in shallow and intermediate depth waters and at the boundary in deep water. Disagreements about the placement of the boundary and the presence, absence and duration of hiatuses hinder more precise conclusions. (4) There appears to be preferential survivorship of epifaunal species into the early Danian with a short interval dominated by infaunal taxa in the earliest Danian. This pattern can best be explained by short-lived input of increased amounts of organic matter at the boundary followed by a sudden collapse of primary productivity and, hence, major reduction or cessation of organic flux to the seafloor. In summary, based on the current dataset, smaller benthic foraminifera, no matter whether they lived in shallow or deep waters, high or low latitudes, or infaunal or epifaunal microhabitats, survived the environmental events across the K–T boundary quite well. Mass extinction does not characterize this group of organisms at this time.     

Classification and identification of the Burkholderia cepacia complex: Past, present and future

The Burkholderia cepacia complex is a group of closely related species with conflicting biological properties. Triggered by the devastating effect of pulmonary infections in cystic fibrosis patients, the scientific community generated an unusually large amount of taxonomic data for these bacteria during the past 15 years. This review presents the polyphasic, multilocus and genomic methodology used for the classification and identification of these bacteria. The current state-of-the-art demonstrates that present day taxonomists can replace traditional DNA-DNA hybridizations for species level demarcation and 16S rRNA sequence analysis for studying phylogeny by superior whole genome sequence-based parameters within the framework of polyphasic taxonomic studies.     

Endangered ecosystems: a review of the conservation status of tropical Asian rivers

Tropical Asian rivers are characterized by their flow seasonality. One (sometimes two) peaks in discharge cause temporary declines in phytoplankton, zooplankton and zoobenthos biomass, but lead to inundation of river floodplains and significant land-water interactions. Fishes undertake lateral or longitudinal breeding migrations within the river system during the flood season, which is marked also by intensive feeding upon allochthonous inputs.Among the diverse human influences upon tropical Asian rivers, three threats stand out. Firstly, degradation of drainage basins (particularly through deforestation and overgrazing) leads to increased suspended sediment loads and extensive flooding. Excessive floodplain siltation alters habitats causing species decline or disappearance. The second threat — river regulation and control — has been practised widely in the region for centuries but, with the planned development of massive projects on the Yangtze and Mekong Rivers, the potential for environmental damage has increased. Flow regulation reduces flood-season peaks, changing the magnitude and extent of floodplain inundation and land-water interactions. Fish breeding migrations may be disrupted, because dams block migration routes or changed flow regimes fail to stimulate reproduction. River pollution is pervasive throughout the region, and constitutes the third threat. Untreated sewage is a particular problem in densely-populated areas, and pollution by industrial effluents and mining wastes is becoming more important. The effects of pollution in tropical Asian rivers are essentially the same as those recorded in north-temperate regions. However, biological understanding has yet to be matched by an ability to halt or limit river degradation.Together, the three threats have led to declines and range constrictions of aquatic animals and those terrestrial species associated with riparian corridors and floodplains. River dolphins and certain crocodilians are particularly threatened, but declines in species of waterfowl, floodplain deer, a host of fishes, macrophytes, and invertebrates have been documented. Reversing the trend is difficult as pollution, flow regulation, and drainage-basin degradation have non-additive detrimental effects on river ecosystems, and enhance the success of exotic invasive species. Moreover, our ability to predict the outcome of man-made changes is hampered by a lack of knowledge of species' life histories and a paucity of data on the trophic basis of production. Despite a lack of detailed information, conservation of tropical Asian rivers will be effected only if limnologists move beyond the bailiwick of science. Ecologically viable management strategies for tropical Asian rivers will succeed only if the socioeconomic context of development plans is taken into account. A failure to rise this challenge will result in the further degradation of these endangered ecosystems.     

Introductions and developments of oysters in the North Sea area: a review

To replenish the exploited native stocks ofOstrea edulis, imports from almost all European coasts have arrived in the North Sea, particularly in the Dutch Oosterschelde estuary. The American oysterCrassostrea virginica and the Portuguese oysterC. angulata have also been imported into the North Sea several times. However, only the introductions of various genetic strains of the Pacific oysterC. gigas have been of lasting success. Spat from British Columbia (Canada) was first imported to the Oosterschelde in 1964. First spatfalls in this area took place in the warm summers of 1975 and 1976. Further larval outbursts occurred in 1982 and 1989, and good settlements took place on culture plots as well as along the dikes of the Oosterschelde. Since 1977 no more cupped oysters have been imported from overseas. The population maintained itself and was able to spread in a northern direction along the Dutch North Sea coast. In Britain, hatchery-producedC. gigas were transferred to several sites, in the 1970s including the British North Sea coast. Here, occurrence in the wild seems to be rather limited up to now. Into the German Wadden Sea,C. gigas larvae and spat from a Scottish hatchery have been introduced since 1971, as were medium-sized oysters from a variety of European sources in the 1980s. Strong spatfalls on intertidal mussel beds in the northern German Wadden Sea occured in 1991 and 1994. For the introductions ofC. gigas along the west European coasts, precautionary measures to minimize unintentional transfers of associated organisms, as recommended by the ICES Code of Practice in 1994, came too late.     

Actinoptychus splendens (Shadbolt) Ralfs (Bacillariophyceae): a biostratigraphic marker for the later part of the Holocene coastal deposits along the southern North Sea

Actinoptychus splendens is a conspicuous and widely distributed marine diatom. At present it is common in the coastal waters of the southern North Sea, but it appears to be absent in the older Holocene deposits along the Dutch and Belgian coasts. Its first postglacial appearance here can be dated at between 4400 and 4100 BP. By 3800 BP it is well established in the region. Although generally not abundant, it can be found in nearly every sample of younger marine or brackish deposits. The large amount of material investigated from the area, as well as the high preservation potential and easy recognition of the species, preclude any other explanation for its apparent absence along southern North Sea shores prior to ±4100 BP, than a late natural immigration. This appears to be quite exceptional, all the common species which generally occur in association with A. splendens being present from the onset of Holocene sedimentation. A. splendens may become an important marker taxon in the Holocene stratigraphy of the coastal plains along the southern North sea.     

Design,synthesis, and conformational studies of the hGM‐CSF derived peptide (13–27)–Gly–(75–87)

An analogue of the human granulocyte–macrophage colony‐stimulating factor (hGM‐CSF), hGM‐CSF(13–27)–Gly–(75–87) was synthesized by solid phase methodology. This analogue was designed to comprise helices A and C of the native growth factor, linked by a glycine bridge. Helices A and C form half of a four‐helix bundle motif in the crystal structure of the native factor and are involved in the interaction with α‐ and β‐chains of the heterodimeric receptor. A conformational analysis of the synthetic analogue by CD, two‐dimensional nmr spectroscopy, and molecular dynamics calculations is reported. The analogue is in a random structure in water and assumes a partially α‐helical conformation in a 1 : 1 trifluoroethanol/water mixture. The helix content in this medium is ∼ 70%. By 2D‐nmr spectroscopy, two helical segments were identified in the sequences corresponding to helices A and C. In addition to medium‐ and short‐range NOESY connectivities, a long‐range cross peak was found between the Cβ proton of Val¹⁶ and NH proton of His⁸⁷ (using the numbering of the native protein). Experimentally derived interproton distances were used as restraints in molecular dynamics calculations, utilizing the x‐ray coordinates as the initial structure. The final structure is characterized by two helical segments in close spatial proximity, connected by a loop region. This structure is similar to that of the corresponding domain in the x‐ray structure of the native growth factor in which helices A and C are oriented in an antiparallel fashion. The N‐terminal residues Gly–Pro of helix C are involved in an irregular turn connecting the two helical segments. As a consequence, helix C is appreciably shifted and slightly rotated with respect to helix A compared to the x‐ray structure of the native growth factor. These small differences in the topology of the two helices could explain the lower biological activity of this analogue with respect to that of the native growth factor. © 1999 John Wiley & Sons, Inc. Biopoly 50: 545–554, 1999