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1.
Katarina Stefanidesova Elena Kocianova Vojtech Boldis Zina Kostanova Pavel Kanka Danka Nemethova Eva Spitalska 《European Journal of Wildlife Research》2008,54(3):519-524
The purpose of this study was to investigate the role of wild animals for Anaplasma phagocytophilum, other ehrlichiae/anaplasmae, Rickettsia helvetica and other rickettsiae and whether different genetic variants of A. phagocytophilum in central Slovakia exist. A total of 109 spleen samples from 49 red deer (Cervus elaphus), 30 roe deer (Capreolus capreolus), 28 wild boar (Sus scrofa) and two mouflon (Ovis musimon) were collected from June 2005 to December 2006. Polymerase chain reaction (PCR) amplification of the16S rRNA gene was used
for detection of ehrlichiae/anaplasmae. A nested PCR targeting part (392 bp) of groESL gene was applied for the specific detection of A. phagocytophilum. Fragments of the gltA and ompA genes (381 bp and 632 bp, respectively) were amplified to detect rickettsiae, followed by sequencing. A. phagocytophilum and R. helvetica were detected in wild animals. The prevalence of A. phagocytophilum was 50.0 ± 18.2% in roe deer and 53.1 ± 14.1% in red deer. None of the 28 wild boar was PCR positive for ehrlichiae/anaplasmae.
A. phagocytophilum was detected in one mouflon. R. helvetica was found in one roe deer. Our study suggests a role of cervids as a natural reservoir of A. phagocytophilum in Slovakia. However, the role of cervids and wild boars in the circulation of R. helvetica remains unknown. The analysis of sequence variation in the msp4 coding region of A. phagocytophilum showed the presence of different variants previously described in ruminants. 相似文献
2.
Cyanobacteria blooms (especially Microcystis spp.) are thought to alter dominance of large-sized daphnids into small-sized metazoan zooplankton. However, several field
investigations show different phenomena. Laboratory experiments were conducted based on the hypothesis that different Microcystis spp. concentrations would influence competitive outcomes using two algal combinations of different concentrations and four
species of cladocerans. In the algal combination of 50 mg l−1 colonial Microcystis spp. + 1 mg l−1
Scenedesmus obliquus (fresh weight), Daphnia carinata was absent during the experiment in competition with other cladocerans. Decreasing colonial Microcystis spp. concentration (10 mg l−1) resulted in a shift from dominance by small-sized cladocerans to dominance by D. carinata. No significant effects of different concentrations of colonial Microcystis spp. on competitive outcomes were shown among three small-sized cladocerans. These results support the idea that cyanobacteria
concentration affects the dominance status of large-bodied daphnid. 相似文献
3.
Since the discovery of the green alga Caulerpa taxifolia in Lake Macquarie (New South Wales, Australia) in 2001, the New South Wales Department of Primary Industries (Fisheries)
has attempted various control methods, including covering the alga with granulated sea salt to induce osmotic shock and cell
lysis. In Lake Macquarie, C. taxifolia often occurs in patches within beds of the native seagrass Zostera capricorni. Although the effects of the salt treatment on blades of Z. capricorni and infauna have been shown to be minimal, there have been no tests of any effects on other native biota, including seagrass
epifauna. In this study, we tested the general hypothesis that the abundance and diversity of epifauna would be reduced by
salting. We used a ‘Beyond BACI’ experimental design whereby epifaunal invertebrates were sampled 3 months, 6 weeks and 6
days before and then again after salting. Epifaunal abundances at the putatively impacted (salted) location were compared
to those at 4 control locations (where no salt was applied). Abundances of most organisms varied significantly among times
and locations with no evidence of the consistent effect of salting on diversity or abundance of epifauna. The study represents
an example of the use of large-scale managerial action as a scientific experiment.
Electronic supplementary material Supplementary material is available for this article at <> and accessible for authorised users 相似文献
4.
The maT clade of transposons is a group of transposable elements intermediate in sequence and predicted protein structure to mariner and Tc transposons, with a distribution thus far limited to a few invertebrate species. We present evidence, based on searches of publicly available databases, that the nematode Caenorhabditis briggsae has several maT-like transposons, which we have designated as CbmaT elements, dispersed throughout its genome. We also describe two additional transposon sequences that probably share their evolutionary history with the CbmaT transposons. One resembles a fold back variant of a CbmaT element, with long (380-bp) inverted terminal repeats (ITRs) that show a high degree (71%) of identity to CbmaT1. The other, which shares only the 26-bp ITR sequences with one of the CbmaT variants, is present in eight nearly identical copies, but does not have a transposase gene and may therefore be cross mobilised by a CbmaT transposase. Using PCR-based mobility assays, we show that CbmaT1 transposons are capable of excising from the C. briggsae genome. CbmaT1 excised approximately 500 times less frequently than Tcb1 in the reference strain AF16, but both CbmaT1 and Tcb1 excised at extremely high frequencies in the HK105 strain. The HK105 strain also exhibited a high frequency of spontaneous induction of unc-22 mutants, suggesting that it may be a mutator strain of C. briggsae. 相似文献
5.
The bacterium Serratia marcescens isolated from surface-sterilised Psoroptes cuniculi was found sensitive to the antibiotic Amikacin. Mites placed in this antibiotic for 48–72 h and then washed by centrifugation were found to be alive and S. marcescens-free. Two experimental infestations were undertaken in order to verify the ability of the S. marcescens-free mites to infect and to give ear skin lesions in healthy rabbits and to evaluate the differential ability of the S. marcescens-free and S. marcescens-infected mites to give ear skin lesions. All rabbits were found to be infested, but only rabbits infested with S. marcescens-free mites presented crusts in their ears, whereas mites and/or eggs were only detected in the ear cerumen of all rabbits infested with S. marcescens-infected mites. S. marcescens was isolated only from P. cuniculi mites taken from these latter rabbits. Results indicate that P. cuniculi mites do not need S. marcescens to live and to be able to infest a healthy rabbit. In addition, S. marcescens was not isolated from eggs and newly born larvae of S. marcescens-infected P. cuniculi, demonstrating that in a population of P. cuniculi this bacterium is not transmitted transovarially. 相似文献
6.
The purpose of our research was to explore the limits of rat-python-Sarcocystis distribution among rats on the offshore tropical islands of Singapore, and to examine the effect of island size, insular isolation, landscape peculiarities and anthropogenic disturbance. Commensal rats (Rattus rattus) inhabited all of these islands, regardless of the islands size, proximity to the mainland, biogeographic features, and/or degree of anthropogenic interference. Rats caught on Sakijang Pelepah Island had well deliminated white bellies that are similar to those of sylvatic or feral rats. The prevalence of Sarcocystis spp. on individual islands ranged from 57 to 100%. This is consistent with the range found in forested habitats on Singapore Island. It also exhibited a similar diversity to Sarcocystis spp. and the predominance of Sarcocystis singaporensis. On Sakijang Pelepah Island, one rat (white bellied) was exceptionally heavily infected with both Sarcocystis villivilosi and Sarcocystis sulawesiensis. The muscles of the rats from nearly all of the islands contained immature sarcocysts, which implies that active transmission is taking place on these islands. This suggests that reticulated pythons (Python reticulatus), which are the definitive hosts of rat Sarcocystis, might have been established or frequented in all the islands of Singapore. Our study shows that the Sarcocystis infection load of the rats was negatively correlated with human disturbance, hinting that human disturbance restricts the pythons mobility and thus, reduces infection of Sarcocytis in the islands rats. 相似文献
7.
The foraging behaviour variability of three striped red mullet (Mullus surmuletus L. 1758) populations with respect to the vegetation cover was examined along the French Mediterranean coasts. We tested both the carrying capacity of different habitats and the hypothesis of a food segregation by the invasive alga Caulerpa taxifolia (Vahl) C. Agardh, on the functioning of benthic fish populations. The results indicated a significant site effect on M. surmuletus foraging behaviour and movements. The vegetation cover may play an important role in modifying the striped red mullet cost of foraging (sampling effort) and thus its strategy of prey capture. As long as the cover of marine phanerogams and/or macrophyte algae (Caulerpaceae) increases, the foraging budget and the distances covered in search of prey decrease significantly. Similarly, the striped red mullet increases the prospected sample periods to augment its foraging success, swimming above the bottom. These changes are related to the development of a dense superficial network of plagiotropic rhizomes and stolons, and to the reduction of space between fronds that limits the accessibility to resources and may increase intra-specific food competition. The role of C. taxifolia does not differ from that of other marine phanerogams but induces significant changes in the structure of Mullidae populations at the local level. The rapid expansion of Caulerpaceae in the Mediterranean Sea could constitute a real threat for the balance of the marine coastal biodiversity and the ecology of M. surmuletus, which is considered a flagship species for coastal Mediterranean demersal fisheries. 相似文献
8.
Stefanie Kimbacher Ingrid Gerstl Branko Velimirov Sylvia Hagemann 《Molecular genetics and genomics : MGG》2009,282(2):165-172
P transposons belong to the eukaryotic DNA transposons, which are transposed by a cut and paste mechanism using a P-element-coded transposase. They have been detected in Drosophila, and reside as single copies and stable homologous sequences in many vertebrate species. We present the P elements Pcin1, Pcin2 and Pcin3 from Ciona intestinalis, a species of the most primitive chordates, and compare them with those from Ciona savignyi. They showed typical DNA transposon structures, namely terminal inverted repeats and target site duplications. The coding
region of Pcin1 consisted of 13 small exons that could be translated into a P-transposon-homologous protein. C. intestinalis and C. savignyi displayed nearly the same phenotype. However, their P elements were highly divergent and the assumed P transposase from C. intestinalis was more closely related to the transposase from Drosophila melanogaster than to the transposase of C. savignyi. The present study showed that P elements with typical features of transposable DNA elements may be found already at the base of the chordate lineage.
Electronic supplementary material The online version of this article (doi:) contains supplementary material, which is available to authorized users. 相似文献
9.
N. Yu. Markelova 《Microbiology》2007,76(6):769-774
The effects of cadmium and diuron, typical environmental pollutants, on the survival of predatory bacteria of the genus Bdellovibrio were studied. The adhesion and cohesion of bdellovibrios were shown to enhance cell resistance to xenobiotics. The viability of Bdellovibrio cells was shown to be higher at the stage of bdelloplasts. The obtained results confirm the concept of the surface-associated existence of Bdellovibrio in the natural environment and serve as a basis for the employment of predatory bacteria to solve the problems of public health, biological protection of ecosystems, and bioterrorism protection. 相似文献
10.
A pure, active cytochrome b
6
f was isolated from the chloroplasts of the marine green alga, Bryopsis
corticulans. To investigate and characterize this cytochrome b
6
f complex, sodium dodecyl sulfate–polyacrylamide gel electrophoresis (SDS–PAGE), absorption spectra measurement and HPLC were employed. It was shown that this purified complex contained four large subunits with apparent molecular masses of 34.8, 24, 18.7 and 16.7 kD. The ratio of Cyt b
6 to Cytf was 2.01 : 1. The cytochromeb
6
f was shown to catalyze the transfer of 73 electrons from decylplastoquinol to plastocyanin–ferricyanide per Cyt f per second. α-Carotene, one kind of carotenoid that has not been found to present in cytochrome b
6
f complex, was discovered in this preparation by reversed phase HPLC. It was different from β-carotene usually found in cytochrome b
6
f complex. The configuration of the major α-carotene component was assigned to be 9-cis by resonance Raman spectroscopy. Different from the previous reports, the configuration of this α-carotene in dissociated state was determined to be all-trans. Besides this carotene, chlorophyll a was also found in this complex. It was shown that the molecular ratios of chlorophylla, cis and all-trans-α-carotene to Cyt f in this complex were 1.2, 0.7 and 0.2, respectively. 相似文献
11.
Paula E. Whitfield Jonathan A. Hare Andrew W. David Stacey L. Harter Roldan C. Muñoz Christine M. Addison 《Biological invasions》2007,9(1):53-64
Less than a decade after being observed off Florida, the invasive Indo-Pacific lionfish is now widely distributed off the
southeast coast of the United States. As a step towards measuring invasion impacts to native communities, we examine the magnitude
and extent of this invasion by first, compiling reports of lionfish to provide range information and second, estimate lionfish
abundance from two separate studies. We also estimate native grouper (epinepheline serranids) abundance to better assess and
compare lionfish abundances. In the first study we conducted SCUBA diver visual transect surveys at 17 different locations
off the North Carolina coast in water depths of 35–50 m. In the second study, we conducted 27 Remote Operated Vehicle (ROV)
transect surveys at five locations from Florida to North Carolina in water depths of 50–100 m. In both studies, lionfish were
found to be second in abundance only to scamp (Mycteroperca phenax). Lionfish were found in higher abundance in the shallower North Carolina SCUBA surveys ( ha−1) than in the deep water ROV surveys ( ha−1). Lionfish reports continue to expand most recently into the Bahamas, raising the specter of further spread into the Caribbean
and Gulf of Mexico. The potential impacts of lionfish to native communities are likely to be through direct predation, competition
and overcrowding. The high number of lionfish present in the ecosystem increases the potential for cascading impacts throughout
the food chain. Within the southeast region the combined effects of climate change, overfishing and invasive species may have
irreversible consequences to native communities in this region.
An erratum to this article can be found at 相似文献
12.
We have investigated the floral ontogeny of Arillastrum, Allosyncarpia, Stockwellia and Eucalyptopsis (of the eucalypt group, Myrtaceae) using scanning electron microscopy and light microscopy. Several critical characters for establishing relationships between these genera and to the eucalypts have been determined. The absence of compound petaline primordia in Arillastrum, Allosyncarpia, Stockwellia and Eucalyptopsis excludes these taxa from the eucalypt clade. Post-anthesis circumscissile abscission of the hypanthium above the ovary in Stockwellia, Eucalyptopsis and Allosyncarpia is evidence that these three taxa form a monophyletic group; undifferentiated perianth parts and elongated fusiform buds are characters that unite Stockwellia and Eucalyptopsis as sister taxa. No floral characters clearly associate Arillastrum with either the eucalypt clade or the clade of Stockwellia, Eucalyptopsis and Allosyncarpia.We gratefully acknowledge Clyde Dunlop and Bob Harwood (Northern Territory Herbarium) for collecting specimens of Allosyncarpia, and Bruce Gray (Atherton) for collecting specimens of Stockwellia. The Australian National Herbarium (CANB) kindly lent herbarium specimens of Eucalyptopsis for examination. This research was supported by a University of Melbourne Research Development Grant to Andrew Drinnan. 相似文献
13.
Notocactus scopa cv. Soonjung was subjected to in planta Agrobacterium tumefaciens-mediated transformation with vacuum infiltration, pin-pricking, and a combination of the two methods. The pin-pricking combined with vacuum infiltration (20-30 cmHg for 15 min) resulted in a transformation efficiency of 67-100%, and the expression of the uidA and nptII genes was detected in transformed cactus. The established in planta transformation technique generated a transgenic cactus with higher transformation efficiency, shortened selection process, and stable gene expression via asexual reproduction. All of the results showed that the in planta transformation method utilized in the current study provided an efficient and time-saving procedure for the delivery of genes into the cactus genome, and that this technique can be applied to other asexually reproducing succulent plant species. 相似文献
14.
Lao M Arencibia AD Carmona ER Acevedo R Rodríguez E León O Santana I 《Plant cell reports》2008,27(6):1103-1111
15.
A pea rust fungus, Uromyces viciae-fabae, has been classified into two varieties, var. viciae-fabae and var. orobi, based on differences in urediniospore wall thickness and putative host specificity in Japan. In principal component analyses, morphological features of urediniospores and teliospores of 94 rust specimens from Vicia, Lathyrus, and Pisum did not show definite host-specific morphological groups. In molecular analyses, 23 Uromyces specimens from Vicia, Lathyrus, and Pisum formed a single genetic clade based on D1/D2 and ITS regions. Four isolates of U. viciae-fabae from V. cracca and V. unijuga could infect and sporulate on P. sativum. These results suggest that U. viciae-fabae populations on different host plants are not biologically differentiated into groups that can be recognized as varieties.Contribution no. 184, Laboratory of Plant Parasitic Mycology, Institute of Agriculture and Forestry, University of Tsukuba, Japan 相似文献
16.
17.
18.
Flower-visiting beetles belonging to three species of Cetoniidae were collected on three mountains near Beijing, China, and yeasts were isolated from the gut of the insects collected. Based
on the 26S rDNA D1/D2 domain and internal transcribed spacer (ITS) region sequence analysis and phenotypic characterization,
four novel anamorphic yeast species located in the Candida albicans/Lodderomyces elongisporus clade were identified from 18 of the strains isolated. The new species and type strains are designated as Candida blackwellae AS 2.3639T (=CBS 10843T), Candida jiufengensis AS 2.3688T (=CBS 10846T), Candida oxycetoniae AS 2.3656T (=CBS 10844T), and Candida pseudojiufengensis AS 2.3693T (=CBS 10847T). C. blackwellae sp. nov. was basal to the branch formed by C. albicans and C. dubliniensis with moderately strong bootstrap support. The closest relative of C. oxycetoniae was L. elongisporus. C. jiufengensis sp. nov. and C. pseudojiufengensis sp. nov. were closely related with each other and formed a branch in a subclade represented by C. parapsilosis and L. elongisporus. 相似文献
19.
Iain Darbyshire 《Kew Bulletin》2008,63(2):261-268
Summary Three new species are described in Barleria L. sect. Stellatohirta M. Balkwill from tropical Africa: B. aristata from south-central Tanzania, B. aenea from south-western Tanzania and northeast Zambia, and B. purpureotincta from south-western Zambia. Their affinities and conservation status are discussed. 相似文献
20.
Field observations and inoculation experiments revealed that Uromyces appendiculatus var. azukicola has an autoecious and macrocyclic life cycle and produces spermogonia, aecia, uredinia, and telia on Vigna angularis var. angularis and V. angularis var. nipponensis. From inoculation experiments, it was suggested that this rust fungus has different host relationships from other varieties. Morphological examinations revealed that the characteristics of urediniospores and teliospores are different among varieties, although aeciospores are morphologically similar to each other.Contribution no. 182, Laboratory of Plant Parasitic Mycology, Institute of Agriculture and Forestry, University of Tsukuba, Japan 相似文献