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1.
《Comptes Rendus Palevol》2013,12(5):269-277
The known European record of the Gondwanan group Podocnemididae begins in the Early Eocene. Neochelys underwent a rapid diversification and was an abundant and diverse representative of this group during the Eocene of Europe from the Early Ypresian to at least the Bartonian. However, several of its species are poorly known, and the phylogenetic relationships among them are poorly understood. A complete shell from the Ypresian of Hérault (southern France) is described here. It is assigned to a new species, Neochelys liriae. The availability of characters of N. liriae is tested by comparison with the other European species, which appear to be well differentiated, and particularly with the neighbouring French taxa N. eocaenica and N. laurenti, of which the latter has been little known to this point.  相似文献   

2.
Phormia regina (the black fly) is a common Holarctic blow fly species which serves as a primary indicator taxon to estimate minimal post mortem intervals. It is also a major research model in physiological and neurological studies on insect feeding. Previous studies have shown a sequence divergence of up to 4.3% in the mitochondrial COI gene between W European and N American P. regina populations. Here, we DNA barcoded P. regina specimens from six N American and 17 W European populations and confirmed a mean sequence divergence of ca. 4% between the populations of the two continents, while sequence divergence within each continent was a ten-fold lower. Comparable mean mtDNA sequence divergences were observed for COII (3.7%) and cyt b (5.3%), but mean divergence was lower for 16S (0.4–0.6%). Intercontinental divergence at nuclear DNA was very low (≤ 0.1% for both 28S and ITS2), and we did not detect any morphological differentiation between N American and W European specimens. Therefore, we consider the strong differentiation at COI, COII and cyt b as intraspecific mtDNA sequence divergence that should be taken into account when using P. regina in forensic casework or experimental research.  相似文献   

3.
Several species of microsporidia are important chronic pathogens of Lymantria dispar in Europe but have never been recovered from North American gypsy moth populations. The major issue for their introduction into North American L. dispar populations is concern about their safety to native non-target insects. In this study, we evaluated the susceptibility of sympatric non-target Lepidoptera to two species of microsporidia, Nosema lymantriae and Vairimorpha disparis, isolated from European populations of L. dispar and applied in field plots in Slovakia. Application of ultra low volume sprays of the microsporidia maximized coverage of infective spores in a complex natural environment and, thus, exposure of non-target species to the pathogens. Of 653 non-target larvae collected from plots treated with V. disparis in 2002, 18 individual larvae representing nine species in four families were infected. These plots were monitored for two subsequent seasons and V. disparis was not recovered from non-target species. Of 2571 non-target larvae collected in N. lymantriae-treated sites, one larva was found to be infected. Both species of microsporidia, particularly N. lymantriae, appear to have a very narrow host range in the field, even when an inundative technique is used for their introduction. V. disparis infections in L. dispar exceeded 40% of recovered larvae in the treated study sites; infection rates were lower in sites sprayed with N. lymantriae. Several naturally-occurring pathogens were recorded from the non-target species. The most common pathogen, isolated from 21 species in eight families, was a microsporidium in the genus Cystosporogenes.  相似文献   

4.
Nosema ceranae was found to infect four different host species including the European honeybee (A. mellifera) and the Asian honeybees (Apis florea, A. cerana and Apis dorsata) collected from apiaries and forests in Northern Thailand. Significant sequence variation in the polar tube protein (PTP1) gene of N. ceranae was observed with N. ceranae isolates from A. mellifera and A. cerana, they clustered into the same phylogenetic lineage. N. ceranae isolates from A. dorsata and A. florea were grouped into two other distinct clades. This study provides the first elucidation of a genetic relationship among N. ceranae strains isolated from different host species and demonstrates that the N. ceranae PTP gene was shown to be a suitable and reliable marker in revealing genetic relationships within species.  相似文献   

5.
Climate change poses direct or indirect influences on physiological mechanisms in plants. In particular, long living plants like trees have to cope with the predicted climate changes (i.e. drought and air warming) during their life span. The present study aimed to quantify the consequences of simulated climate change for foliar N metabolites over a drought-rewetting-drought course. Saplings of three Central European oak species (i.e. Quercus robur, Q. petraea, Q. pubescens) were tested on two different soil types (i.e. acidic and calcareous). Consecutive drought periods increased foliar amino acid-N and soluble protein-N concentrations at the expense of structural N in all three oak species. In addition, transient effects on foliar metabolite dynamics were observed over the drought-rewetting-drought course. The lowest levels of foliar soluble protein-N, amino acid-N and potassium cation with a minor response to drought and air warming were found in the oak species originating from the driest/warmest habitat (Q. pubescens) compared to Q. robur and Q. petraea. Higher foliar osmolyte-N and potassium under drought and air warming were observed in all oak species when grown on calcareous versus acidic soil. These results indicate that species-specific differences in physiological mechanisms to compensate drought and elevated temperature are modified by soil acidity.  相似文献   

6.
Nosema ceranae is a microsporidian parasite described from the Asian honey bee, Apis cerana. The parasite is cross-infective with the European honey bee, Apis mellifera. It is not known when or where N. ceranae first infected European bees, but N. ceranae has probably been infecting European bees for at least two decades. N. ceranae appears to be replacing Nosema apis, at least in some populations of European honey bees. This replacement is an enigma because the spores of the new parasite are less durable than those of N. apis. Virulence data at both the individual bee and at the colony level are conflicting possibly because the impact of this parasite differs in different environments. The recent advancements in N. ceranae genetics, with a draft assembly of the N. ceranae genome available, are discussed and the need for increased research on the impacts of this parasite on European honey bees is emphasized.  相似文献   

7.
Despite recent advances in the understanding of the interplay between a dynamic physical environment and phylogeography in Europe, the origins of contemporary Irish biota remain uncertain. Current thinking is that Ireland was colonized post-glacially from southern European refugia, following the end of the last glacial maximum (LGM), some 20 000 years BP. The Leisler''s bat (Nyctalus leisleri), one of the few native Irish mammal species, is widely distributed throughout Europe but, with the exception of Ireland, is generally rare and considered vulnerable. We investigate the origins and phylogeographic relationships of Irish populations in relation to those across Europe, including the closely related species N. azoreum. We use a combination of approaches, including mitochondrial and nuclear DNA markers, in addition to approximate Bayesian computation and palaeo-climatic species distribution modelling. Molecular analyses revealed two distinct and diverse European mitochondrial DNA lineages, which probably diverged in separate glacial refugia. A western lineage, restricted to Ireland, Britain and the Azores, comprises Irish and British N. leisleri and N. azoreum specimens; an eastern lineage is distributed throughout mainland Europe. Palaeo-climatic projections indicate suitable habitats during the LGM, including known glacial refugia, in addition to potential novel cryptic refugia along the western fringe of Europe. These results may be applicable to populations of many species.  相似文献   

8.
Pathogens and parasites represent significant threats to the health and well-being of honeybee species that are key pollinators of agricultural crops and flowers worldwide. We conducted a nationwide survey to determine the occurrence and prevalence of pathogens and parasites in Asian honeybees, Apis cerana, in China. Our study provides evidence of infections of A. cerana by pathogenic Deformed wing virus (DWV), Black queen cell virus (BQCV), Nosema ceranae, and C. bombi species that have been linked to population declines of European honeybees, A. mellifera, and bumble bees. However, the prevalence of DWV, a virus that causes widespread infection in A. mellifera, was low, arguably a result of the greater ability of A. cerana to resist the ectoprasitic mite Varroa destructor, an efficient vector of DWV. Analyses of microbial communities from the A. cerana digestive tract showed that Nosema infection could have detrimental effects on the gut microbiota. Workers infected by N. ceranae tended to have lower bacterial quantities, with these differences being significant for the Bifidobacterium and Pasteurellaceae bacteria groups. The results of this nationwide screen show that parasites and pathogens that have caused serious problems in European honeybees can be found in native honeybee species kept in Asia. Environmental changes due to new agricultural practices and globalization may facilitate the spread of pathogens into new geographic areas. The foraging behavior of pollinators that are in close geographic proximity likely have played an important role in spreading of parasites and pathogens over to new hosts. Phylogenetic analyses provide insights into the movement and population structure of these parasites, suggesting a bidirectional flow of parasites among pollinators. The presence of these parasites and pathogens may have considerable implications for an observed population decline of Asian honeybees.  相似文献   

9.
We examined phylogeographic differentiation of the red-eyed grass snake (Natrix astreptophora) using 1984 bp of mtDNA and 13 microsatellite loci from specimens collected across its distribution range in southwestern Europe and northwestern Africa. Based on phylogenetic analyses of mtDNA, European N. astreptophora constituted the sister clade to a weakly supported North African clade comprised of two deeply divergent and well-supported clades, one corresponding to Moroccan snakes and the other to snakes from Algeria and Tunisia. This tripartite differentiation was confirmed by analyses of microsatellite loci. According to a fossil-calibrated molecular clock, European and North African N. astreptophora diverged 5.44 million years ago (mya), and the two Maghrebian clades split 4.64 mya. These dates suggest that the radiation of the three clades was initiated by the environmental changes related to the Messinian Salinity Crisis and the reflooding of the Mediterranean Basin. The differentiation of N. astreptophora, with distinct clades in the Iberian Peninsula and in the western and eastern Maghreb, corresponds to a general phylogeographic paradigm and resembles the differentiation found in another co-distributed Natrix species, the viperine snake (N. maura). Despite both species being good swimmers, the Strait of Gibraltar constitutes a significant biogeographic barrier for them. The discovery that North Africa harbours two endemic lineages of N. astreptophora necessitates more conservation efforts for these imperilled snakes.  相似文献   

10.
The microsporidium Nosema ceranae is detected in honeybees in Thailand for the first time. This endoparasite has recently been reported to infect most Apis mellifera honeybee colonies in Europe, the US, and parts of Asia, and is suspected to have displaced the endemic endoparasite species, Nosema apis, from the western A. mellifera. We collected and identified species of microsporidia from the European honeybee (A. mellifera), the cavity nesting Asian honeybee (Apis cerana), the dwarf Asian honeybee (Apis florea) and the giant Asian honeybee (Apis dorsata) from colonies in Northern Thailand. We used multiplex PCR technique with two pairs of primers to differentiate N. ceranae from N. apis. From 80 A. mellifera samples, 62 (77.5%) were positively identified for the presence of the N. ceranae. Amongst 46 feral colonies of Asian honeybees (A. cerana, A. florea and A. dorsata) examined for Nosema infections, only N. ceranae could be detected. No N. apis was found in our samples. N. ceranae is found to be the only microsporidium infesting honeybees in Thailand. Moreover, we found the frequencies of N. ceranae infection in native bees to be less than that of A. mellifera.  相似文献   

11.
European hare Lepus europaeus populations have undergone recent declines but the species has successfully naturalised in many countries outside its native range. It was introduced to Ireland during the mid-late nineteenth century for field sport and is now well established in Northern Ireland. The native Irish hare Lepus timidus hibernicus is an endemic subspecies of mountain hare L. timidus and has attracted major conservation concern following a long-term population decline during the twentieth century and is one of the highest priority species for conservation action in Ireland. Little is known about the European hare in Ireland or whether it poses a significant threat to the native mountain hare subspecies by compromising its ecological security or genetic integrity. We review the invasion ecology of the European hare and examine evidence for interspecific competition with the mountain hare for habitat space and food resources, interspecific hybridisation, disease and parasite transmission and possible impacts of climate change. We also examine the impact that introduced hares can have on native non-lagomorph species. We conclude that the European hare is an emerging and significant threat to the conservation status of the native Irish hare. Invasive mammal species have been successfully eradicated from Ireland before and immediate action is often the only opportunity for cost-effective eradication. An urgent call is issued for further research whilst the need for a European hare invasive Species Action Plan (iSAP) and Eradication strategy are discussed.  相似文献   

12.
According to the refugee species concept, increasing replacement of open steppe by forest cover after the last glacial period and human pressure had together forced European bison (Bison bonasus)—the largest extant terrestrial mammal of Europe—into forests as a refuge habitat. The consequent decreased fitness and population density led to the gradual extinction of the species. Understanding the pre-refugee ecology of the species may help its conservation management and ensure its long time survival. In view of this, we investigated the abundance of stable isotopes (δ13C and δ15N) in radiocarbon dated skeletal remains of European bison and other large herbivores—aurochs (Bos primigenius), moose (Alces alces), and reindeer (Rangifer tarandus)—from the Early Holocene of northern Europe to reconstruct their dietary habits and pattern of habitat use in conditions of low human influence. Carbon and nitrogen isotopic compositions in collagen of the ungulate species in northern central Europe during the Early Holocene showed significant differences in the habitat use and the diet of these herbivores. The values of the δ13C and δ15N isotopes reflected the use of open habitats by bison, with their diet intermediate between that of aurochs (grazer) and of moose (browser). Our results show that, despite the partial overlap in carbon and nitrogen isotopic values of some species, Early Holocene large ungulates avoided competition by selection of different habitats or different food sources within similar environments. Although Early Holocene bison and Late Pleistocene steppe bison utilized open habitats, their diets were significantly different, as reflected by their δ15N values. Additional isotopic analyses show that modern populations of European bison utilize much more forested habitats than Early Holocene bison, which supports the refugee status of the species.  相似文献   

13.
The relationships between Afrotropical and Palaearctic Crocidurinae species have been evaluated on the basis of inter-SINE-PCR (IS-PCR). Two SINE families have been studied: mammalian interspersed repeats (MIR) and a short retroposon SOR, specific to the family Soricidae. Use of neighbor-joining and maximum parsimony analyses allowed us to recognize three major groupings: (i) 50-chromosome African species (C. parvipes and C. olivieri) and 28-chromosome European C. leucodon; (ii) species endemic to Ethiopia (36-chromosome C. thalia, C. glassi, Crocidura sp. B, united with C. macmillani and C. baileyi); (iii) Palaearctic 40-chromosome species group. Therefore, the major groupings of Crocidura shrews in the phylogenetic analysis of IS-PCR results cannot be distinguished as Palaearctic and Afrotropical groups of species: European C. leucodon unites with African 50-chromosome species with a high bootstrap support. The affiliation of Suncus murinus with Eurasian grouping is only supported by low bootstrap values.  相似文献   

14.
Anthropogenically increased input of nitrogen (N) and phosphorous (P) have led to a severe reduction of plant species richness in European semi-natural grasslands. Although it is well established that this species loss is not trait neutral, a thorough analysis of the effects of nutrient addition on trait based functional diversity and functional composition, independently of species loss, is lacking so far. We compiled data on the plant species abundance (relevé’s) of 279 Nardus grasslands from nine European countries, across a gradient of soil N and P content. Functional diversity (Petchy and Gaston’s FDc, weighted FDc and quadratic entropy) and mean trait composition were calculated for each relevé, based on 21 functional traits. Differences in functional diversity and functional composition were related to differences in soil N, atmospheric N deposition, soil P and pH, while controlling for geographic location and species richness. All functional diversity measures decreased with increasing soil N, with wFDc also decreased by soil P, independent of species loss. This was accompanied by clear shifts in functional trait composition, associated with shifts from below-ground competition for nutrients to above-ground competition for light. This resulted in a decrease in insect-pollinated therophytes and chamaephytes and an increase in long-lived, clonal graminoids and hemicryptophytes under increasing soil N and P. These functional community changes can be expected to alter both ecosystem functioning and service provisioning of the studied grasslands. Our research emphasizes the importance of a reduction of both N and P emission throughout Europe for sustainable conservation of these communities.  相似文献   

15.
Invasions of Ponto-Caspian gobiid fishes are suspected to cause regime shifts in freshwater ecosystems. This study compared the trophic niche differentiations of Neogobius melanostomus and Ponticola kessleri in the upper Danube River using stable isotope analyses (δ13C and δ15N), gut content analyses and morphometric analyses of the digestive tract. Both species were identified as predacious omnivores with high dietary overlap and a generalistic feeding strategy. Amphipods (especially invasive Dikerogammarus spp.) contributed 2/3 to the index of food importance. δ15N-signatures of N. melanostomus revealed an ontogenetic diet shift and significantly exceeded those in P. kessleri by ~1.5‰, indicating a niche separation of half a trophic level. P. kessleri had shorter uncoiled intestinal tracts than N. melanostomus, indicating a narrower niche and adaptation to animal food. Trophic niches in both species expanded during the growth period with increasing intraguild predation and cannibalism in P. kessleri and increasing molluscivory in N. melanostomus. P. kessleri showed a higher degree of specialization and more stable feeding patterns across seasons, whereas N. melanostomus adapted its diet according to the natural prey availability. The feeding patterns of both species observed in the upper Danube River strongly differ from those in their native ranges, underlining their great plasticity. Both goby species consumed mainly other non-native species (~92% of gut contents) and seemed to benefit from previous invasions of prey species like Dikerogammarus villosus. The invasive success of gobies and their prey mirror fundamental ecological changes in large European freshwater ecosystems.  相似文献   

16.
Nocardia are known to be a facultative human pathogen and can cause infection in immune compromised patients. Though the details research on the virulence factors of Nocardia are scanty but numerous genes that code such factors were reported from different species of Nocardia. Despite of the presence of several virulence factors, species of this genus have been shown to have role in remediation of many toxic and hazardous materials from the environment. In this study, genome sequences of rubber degrading Nocardia sp. BSTN01 and N.nova SH22a have been analyzed to locate the potential virulence genes. Also, the genomes of facultative pathogenic Nocardia like, N.africana, N. brasiliensis, N. kruczakiae, N. transvalensis and N. veterana have been analyzed to find the gene encoding latex clearing protein (Lcp), a rubber oxygenase enzyme of Gram-positive action bacteria. The study provides an insight about the potentiality of rubberdegrading Nocardia species to emerge as future human pathogens and also the probability of a serious concern if the studied facultative pathogens of Nocardia like N. africana, N. brasiliensis, N. kruczakiae, N. transvalensis and N. veterana are capable of degrading rubber, a regularly used material in clinics. Moreover, use of such possible pathogenic strains for their known role in bioremediation of rubber waste from the environment might be deleterious.  相似文献   

17.
18.
With the establishment of the Natura 2000 (N2000) network, the European Union intends to develop strategies to conserve Europe's threatened habitats and species, including bats. Forest-dwelling bats are highly reliant on forest structures, such as snags and hollow trees, which the bats need as roosts. The decrease in such forest microhabitats significantly affects the habitat use and, therefore, the activity in forests. To determine whether N2000 beech forests under active timber production offer better habitats for bats compared to commercially used non-N2000 forests, we measured the bat activity and assessed the potential roosts in trees and snags in eleven pairs of stands. All survey stands represented mesotrophic beech forests (Fagus sylvatica L.) of the N2000 habitat type 9130 (Asperulo-Fagetum) in three European Biogeographic Regions. The activity of all bat species, the activity of priority N2000 species, the species number, the number of trees with roosts and the snag volume did not differ significantly between the N2000 and non-N2000 stands. We conclude that the current management of the N2000 beech forests is almost identical to that of non-N2000 commercial forests, and thus, the N2000 status has not led to an increase of bat-relevant habitat variables yet. Consequently, additional efforts beyond the administrative assignment of N2000 areas are required to build and ensure an ecologically effective and sustainable network of beech forests in Europe, including increasing important forest requirements for bats, such as roosts and snags.  相似文献   

19.
Putative PISTILLATA genes were generated in nine species of Neillia, to examine the phylogenetic relationships among the species, and to test the hypothesis of hybrid origin within the genus. The PI genes determined in Neillia have two introns in the I-box region, which is consistent with PI genes in other Rosaceae. Phylogenetic analyses of the I-box region, including the introns, indicated that the species formerly classified in Stephanandra were nested within Neillia, supporting the taxonomic merger of the two genera. The PI data do not have a sufficiently strong signal to reject the hypothesis that Stephanandra is a hybrid in origin. The PI data, in conjunction with nuclear LEAFY, ribosomal DNA, and chloroplast DNA data, suggest that N. affinis might have been derived from hybridization between N. thibetica and N. gracilis. The phylogenetic position of N. affinis in the N. thibetica clade is supported by the PI and rDNA data, whereas N. affinis is also supported as a sister to N. gracilis in the LEAFY and cpDNA data. The pattern of phylogenetic placements of N. affinis in two different clades in two different sets of data suggests that the genome of the species might be comprised of a combination of the putative parental species.  相似文献   

20.
To this day, the only sturgeon to be listed on the French vertebrate inventory is the European sturgeon (Acipenser sturio Linnaeus, 1758). The recent study of sturgeon remains on various French archaeological sites shows the presence of another species: the Atlantic sturgeon (A. oxyrinchus Mitchill 1815). This species already existed in the French Atlantic region at the end of the Neolithic Age 5000 years ago and was still to be found 3000 years later. Thus the A. oxyrinchus determined in several Baltic medieval sites are neither the only nor the first sturgeons to have inhabited European waters. Sturgeon restoration projects in European rivers necessitate a precise determination of the native species. In the case of relict or extinct species, the bone remains found on archaeological sites represent the most reliable source of information. This discovery will also be the starting point of palaeogenetical research (mitochondrial and cellular aDNA) and will give information about the genetic diversity of these threatened or recently extinct populations.  相似文献   

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