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1.
The Diversity of Bacterial Communities Associated with Atlantic Cod <Emphasis Type="Italic">Gadus morhua</Emphasis> 总被引:1,自引:0,他引:1
The spatial and temporal changes in the bacterial communities associated with the Atlantic cod Gadus morhua were investigated using terminal restriction fragment length polymorphism (T-RFLP) analysis of 16S recombinant DNA (rDNA).
Epidermal mucous was sampled from 366 cod caught in three harvest locations (Baltic, Icelandic, and North Seas) over three
seasons (spring 2002, autumn 2002, and spring 2003), and an automated method for the high-throughput processing of environmental
samples was developed using a Qiagen BioRobot. The analysis revealed that a diverse consortium of bacteria were found on fish;
γ-proteobacteria and Cytophaga–Flavobacter–Bacteroides (CFB) species were dominant. T-RFLP peak profiles suggested that operational taxonomic units (OTUs) related to Photobacterium sp., Psychrobacter sp., and Bacteroides sp. were common to all sites in all three seasons, but there were intersite variations in community composition. Cod caught
from different seas had distinct reproducible bacterial assemblages. Whereas communities from fish caught in the Baltic and
Icelandic Seas were relatively stable over the three seasons, those from fish from the North Sea changed significantly over
time. 相似文献
2.
In the northern hemisphere, pike (Esox lucius Linnaeus) is one of the most important recreational fisheries resources, and regulatory or voluntary catch-and-release angling
is common. No information is available about the potential sublethal impacts on pike that catch-and-release fishing may cause,
such as behavioural alterations and changes in habitat choice after release. Radio telemetry with N = 20 pike was used to test the hypothesis that fish modify behaviour by reducing movement as a reaction to a catch-and-release
event in a previously unfished, slightly eutrophic lake, having an area of 25 ha and located in northeastern Germany. During
a 7-month tracking period, activity of pike was monitored for consecutive 24 h every week. Minimum displacement per hour (m)
and distance to shore (m) were significantly lower upon the first post release tracking compared to tracking before the capture.
Two tracking events after capture, both movement and distance to shore were similar to those measured during pre-angling.
There were no significant relations between the change in movement and distance to shore and size of pike. In terms of habitat
choice, pike significantly selected for reed and avoided the pelagic area over the whole study period that was not influenced
by catch-and-release angling. The results indicated that catch-and-release induces short-term behavioural alterations in pike,
probably explained by physiological disturbances and facilitated by evolved anti-predation behaviours. Such alterations, however,
seem to be of short duration and reversible suggesting sublethal catch-and-release impacts on pike behaviour are limited.
Guest editors: J. M. Farrell, C. Skov, M. Mingelbier, T. Margenau & J. E. Cooper
International Pike Symposium: Merging Knowledge of Ecology, Biology, and Management for a Circumpolar Species 相似文献
3.
Escherichia coliL-asparaginase, an antileukaemic agent in man1, inhibits in vitro mitogen or antigen-induced blastogenesis in man2,3 and in animals (M. Bennett, E. G. Mayhew and T. Han, unpublished data) and suppresses bone-marrow derived antibody precursor cells in the mouse4. We now report that another L-asparaginase preparation—from Erwinia carotovora—also possesses antileukaemic activity5,6 and has a more pronounced immunosuppressive effect on in vitro blastogenesis than the E. coli enzyme. 相似文献
4.
Ottem KF Nylund A Karlsbakk E Friis-Møller A Krossøy B 《Archives of microbiology》2007,187(5):343-350
A Francisella sp., isolate GM2212T, previously isolated from diseased farmed Atlantic cod Gadus morhua in Norway is characterized. The complete 16S rDNA, 16S–23S intergenic spacer, 23S rDNA, 23S–5S intergenic spacer, 5S rDNA,
FopA, lipoprotein TUL4 (LpnA), malate dehydrogenase and a hypothetical lipoprotein (LpnB) is sequenced and compared with Francisella tularensis and Francisella philomiragia. All these sequences support a close relationship between GM2212T and F. philomiragia. The bacterium grows at 10–25°C with an optimum at about 20°C, a temperature range clearly different from F. tularensis and F. philomiragia. GM2212T is catalase-positive, indole positive, oxidase-negative, do not produce H2S in Triple Sugar Iron agar, and does not hydrolyze gelatin, is resistant to erythromycin and susceptible to ceftazidime,
the latter five characteristics separating it from F. philomiragia. Cysteine enhances growth. Acid is produced from d-glucose, maltose, sucrose (weak) but not from lactose or glycerol. GM2212T grows on both MacConkey agar and in nutrient broth (6% NaCl). The bacterium is resistant to trimethoprim-sulfamethoxazole,
penicillines, cefuroxime and erythromycin; but is susceptible to ceftazidime, tetracycline, gentamicin, ciprofloxacin. Based
on the molecular and phenotypical characteristics, we suggest that this GM2212 isolate, may represent a new species of Francisella. Isolate GM2212T (=CNCM I-3481T = CNCM I-3511T = DSM 18777T). 相似文献
5.
6.
Two repeated DNA sequences isolated from a partial genomic DNA library of Helianthus annuus, p HaS13 and p HaS211, were shown to represent portions of the int gene of a Ty3 /gypsy retroelement and of the RNase-Hgene of a Ty1 /copia retroelement, respectively. Southern blotting patterns obtained by hybridizing the two probes to BglII- or DraI-digested genomic DNA from different Helianthus species showed p HaS13 and p HaS211 were parts of dispersed repeats at least 8 and 7 kb in length, respectively, that were conserved in all species studied. Comparable hybridization patterns were obtained in all species with p HaS13. By contrast, the patterns obtained by hybridizing p HaS211 clearly differentiated annual species from perennials. The frequencies of p HaS13- and p HaS211-related sequences in different species were 4.3x10(4)-1.3x10(5) copies and 9.9x10(2)-8.1x10(3) copies per picogram of DNA, respectively. The frequency of p HaS13-related sequences varied widely within annual species, while no significant difference was observed among perennial species. Conversely, the frequency variation of p HaS211-related sequences was as large within annual species as within perennials. Sequences of both families were found to be dispersed along the length of all chromosomes in all species studied. However, Ty3 /gypsy-like sequences were localized preferentially at the centromeric regions, whereas Ty1/ copia-like sequences were less represented or absent around the centromeres and plentiful at the chromosome ends. These findings suggest that the two sequence families played a role in Helianthusgenome evolution and species divergence, evolved independently in the same genomic backgrounds and in annual or perennial species, and acquired different possible functions in the host genomes. 相似文献
7.
M. A. Dmitrieva 《Journal of Ichthyology》2016,56(2):247-258
The interannual and ontogenetic dynamics of the fecundity of the Baltic cod Gadus morhua callarias and the dependence of the number of the offspring on the reproduction conditions were studied. The absolute individual fecundity and the relative individual fecundity had no pronounced interannual dynamics for the period of 1994?2013. The maximal population fecundity was observed in early 1980, the minimal, in 1990?2000. Nearly every year, the highest contribution to the population fecundity belongs to the 4?5-year old females. The ranking of the survival rates and the year-class strength for the females at the age of 2 years showed that the emergence of the generations of high and average productivity (1980?1986) referred to the unfavorable and moderate survival conditions during the early ontogenesis. During the period of small stock (after 1987), the conditions were mostly favorable and moderate. It is suggested that the significant role in the offspring dynamics belongs to the factors linked to the population density. After 2005, favorable survival conditions promoted the increase of the Baltic cod abundance; this increase was also supported by the decrease of the commercial fishing and by the sporadic large-scale advective processes. 相似文献
8.
New combinations are proposed in anticipation of the Polygonaceae treatment in the forthcoming volume of Intermountain Flora:
Polygonum kelloggii var. esotericum, P. kelloggii var. watsonii
,
Rumex densiflorus var. pycnanthus
,
R. salicifolius var. utahensis, and R. occidentalis var. tomentellus. Typifications are proposed to facilitate ongoing studies in Polygonaceae and to maintain current usage. 相似文献
9.
Shahriar Saiedian Ezzatollah Keyhani Jacqueline Keyhani 《Acta Physiologiae Plantarum》2007,29(5):463-471
Crocus sativus L., cultivated since ancient times as the source of saffron, is a triploid plant that can be propagated only via its corms
which undergo a period of dormancy. Understanding the processes taking place in the corm is essential to preserve the plant
and improve its quality. Color and taste being of prime importance in the quality of the saffron spice, knowledge on polyphenol
oxidase (PPO) activity in the plant is of particular interest given the role of the enzyme in fruit and vegetable browning
during processing and during the storage of processed food. In this paper, PPO activity was investigated for the first time
in extracts obtained from dormant C. sativus L. corms. PPO activity was detectable using l-DOPA, pyrogallol, catechol or p-cresol as substrate, each being oxidized to its corresponding o-quinone; no activity was detectable with l-tyrosine, tyramine or phenol as substrate. Two pH optima, respectively at 4.5 and 6.7, were observed with all substrates
and a third one, at 8.5, was found with l-DOPA and p-cresol. Kinetics parameters studied at pH 6.7 indicated the highest catalytic efficiency (in units mg−1 prot mM−1) with pyrogallol: 150, then catechol: 39, l-DOPA: 6.4 and p-cresol: 4.6. The enzymatic activity was inhibited by 50% in the presence of 0.22, 0.35, 0.5 and 0.7 mM kojic acid with, respectively,
catechol, pyrogallol, p-cresol and l-DOPA as substrate. When stained for PPO activity, non-denaturing gel electropherograms of extract revealed three distinct
bands, indicating the presence of multiple isoenzymes in dormant C. sativus L. corms. 相似文献
10.
Martina Beranová Slavomír Rakouský Zuzana Vávrová Tomáš Skalický 《Plant Cell, Tissue and Organ Culture》2008,94(3):253-259
A sonication-assisted, Agrobacterium-mediated, co-cultivation technique was used in an attempt to increase the transformation efficiency of flax. Hypocotyls and
cotyledons excised from about 10-day-old flax seedlings grown in vitro were placed into a 10 mM MgSO4 solution, and inoculated with an A. tumefaciens vector bearing the mgfp5-ER gene driven by the CaMV 35S promoter. The explants were subjected to pulses of ultrasound delivered by a sonicator apparatus
(35 kHz) for 0–150 s and co-cultivated for 2 h at 27°C. The dried hypocotyls and cotyledons were grown on a selective MS medium
to promote shoot regeneration. An electron microscopic study showed that the sonication treatment resulted in thousands of
microwounds on and below the surface of the explants. A stereo microscope Leica MZ 12 equipped with a GFP adaptor was used
to assess the infection and transformation of plant tissues in real time. After only 48 h and for at least 30 days after bacteria
elimination, signs of transgene expression could be seen as a bright fluorescence. Our results show that treatment with ultrasound
facilitates an enhanced uptake of plasmid DNA into the cells of flax hypocotyls and cotyledons and that its efficiency depends
on the duration of the treatment and the frequency used. SAAT could be a promising tool for enhancing transformation efficiency
in flax. 相似文献
11.
Nguyen Hoang Loc Nguyen Van Song Nguyen Quang Duc Tien Tang Thuy Minh Phan Thi Quynh Nga Tae-Geum Kim Moon-Sik Yang 《Plant Cell, Tissue and Organ Culture》2011,105(1):39-45
A gene encoding the B subunit of the enterotoxigenic Escherichia coli heat-labile enterotoxin (LTB) was adapted to the optimized plant coding sequence, and fused to the endoplasmic reticulum
retention signal SEKDEL in order to enhance its expression level and protein assembly in plants. The synthetic LTB (sLTB)
gene was placed into a plant expression vector under the control of the CaMV 35S promoter, and subsequently introduced into
the watercress (Nasturtium officinale L.) plant by the Agrobacterium-mediated transformation method. The integration of the sLTB gene into the genomic DNA of transgenic plants was confirmed
by genomic DNA PCR amplification. The assembly of plant-produced LTB protein was detected by western blot analysis. The highest
amount of LTB protein produced in transgenic watercress leaf tissue was approximately 1.3% of the total soluble plant protein.
GM1-ganglioside enzyme-linked immunosorbent assay indicated that plant-synthesized LTB protein bound specifically to GM1-ganglioside, which is the receptor for biologically active LTB on the cell surface, suggesting that the plant-synthesized
LTB subunits formed biologically active pentamers. 相似文献
12.
Karin Sonntag Brigitte Ruge-Wehling Peter Wehling 《Plant Cell, Tissue and Organ Culture》2009,96(3):297-305
A method for isolation and shoot regeneration from electrofused protoplasts of L. angustifolius and L. subcarnosus was developed. Viable protoplasts were isolated from leaves of in-vitro grown seedlings at an average yield of 6 × 105 protoplasts g−1 fresh weight. Liquid and agarose solidified B5 media were used for protoplast culture. In the liquid-culture system, all
tested media, VKM, P1 and KM8p, were applicable for inducing cell division (84% of all tested petri dishes at four weeks)
and colony formation. Media containing additional carbohydrates were suitable to produce compact calli with green and brown
pigmentations in different combinations. Analysis of callus with molecular markers allowed to identify six somatic hybrids.
However, none of the parental-protoplast derived cell colonies could develop shoots. This is the first report on protoplast
fusion of L. angustifolius and L. subcarnosus with subsequent shoot regeneration. 相似文献
13.
Hugh D. Wilson 《Economic botany》1990,44(3):92
Traditionally viewed as an Andean grain crop,Chenopodium quinoa Willd. includes domesticated populations that are not Andean, and Andean populations that are not domesticated. Comparative analysis of leaf morphology and allozyme frequencies have demonstrated that Andean populations, both domesticated(quinua) and free-living(ajara), represent an exceptionally homogeneous unit that is well differentiated from allied domesticates of coastal Chile(quingua) and freeliving populations of the Argentine lowlands(C. hircinum). This pattern of relationships indicates that Andean populations represent a monophyletic crop/weed system that has possibly developed through cyclic differentiation (natural vs. human selection) and introgressive hybridization. Relative levels of variation suggest that this complex originated in the southern Andes, possibly from wild types allied withC. hircinum, with subsequent dispersal north to Colombia and south to the Chilean coast. Coastal populations were apparently isolated from post-dispersal differentiation and homogenization that occurred in the Andes. Other data point toward a center of origin in the northern Andes with secondary centers of genetic diversity subsequently developing in the southern Andes and the plains of Argentina. Comparative linkage of South American taxa, all tetraploid, with North American tetraploids of the subsection will eventually clarify this problem. While the possibility of a direct phyletic connection betweenC. quinoa and the Mexican domesticate(C. berlandieri subsp. nuttalliae,) cannot be excluded, available evidence indicates that the latter represents an autonomous lineage that is associated with the basal tetraploid, C. b. subsp.berlandieri, through var.sinuatum, whereas South American taxa show possible affinities to either var. zschackei or var.berlandieri. An extinct domesticate of eastern North America,C. b. subsp.jonesianum, represents either another instance of independent domestication, possibly from subsp. b. var.zschackei, or a northeastern outlier of subsp.nuttalliae. 相似文献
14.
15.
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
16.
Poulícková A 《Folia microbiologica》2008,53(2):125-129
Single (unpaired) vegetative cells of freshwater pennate diatom Neidium cf. ampliatum differentiated into gametangia and produced a single zygote (auxospore) via a pedogamic process. The gametic nuclei fused after auxospore expansion had begun. The auxospore expanded in parallel to the apical axis of the gametangium. 相似文献
17.
Background
Gonadotropin releasing hormone (GnRH) is responsible for stimulation of gonadotropic hormone (GtH) in the hypothalamus-pituitary-gonadal axis (HPG). The regulatory mechanisms responsible for brain specificity make the promoter attractive for in silico analysis and reporter gene studies in zebrafish (Danio rerio).Results
We have characterized a zebrafish [Trp7, Leu8] or salmon (s) GnRH variant, gnrh 3. The gene includes a 1.6 Kb upstream regulatory region and displays the conserved structure of 4 exons and 3 introns, as seen in other species. An in silico defined enhancer at -976 in the zebrafish promoter, containing adjacent binding sites for Oct-1, CREB and Sp1, was predicted in 2 mammalian and 5 teleost GnRH promoters. Reporter gene studies confirmed the importance of this enhancer for cell specific expression in zebrafish. Interestingly the promoter of human GnRH-I, known as mammalian GnRH (mGnRH), was shown capable of driving cell specific reporter gene expression in transgenic zebrafish.Conclusions
The characterized zebrafish Gnrh3 decapeptide exhibits complete homology to the Atlantic salmon (Salmo salar) GnRH-III variant. In silico analysis of mammalian and teleost GnRH promoters revealed a conserved enhancer possessing binding sites for Oct-1, CREB and Sp1. Transgenic and transient reporter gene expression in zebrafish larvae, confirmed the importance of the in silico defined zebrafish enhancer at -976. The capability of the human GnRH-I promoter of directing cell specific reporter gene expression in zebrafish supports orthology between GnRH-I and GnRH-III.18.
Studying Pneumocystis has proven to be a challenge from the perspective of propagating a significant amount of the pathogen in a facile manner.
The study of several fungal pathogens has been aided by the use of invertebrate model hosts. Our efforts to infect the invertebrate
larvae Galleria
mellonella with Pneumocystis proved futile since P. murina neither caused disease nor was able to proliferate within G. mellonella. It did, however, show that the pathogen could be rapidly cleared from the host. 相似文献
19.
Noel H. Holmgren 《Brittonia》2018,70(1):115-139
A revision of Penstemon sect. Saccanthera subsect. Serrulati includes a new species (P. salmonensis), a new variety (P. triphyllus var. infernalis), and the elevation of a subspecies to species (P. curtiflorus), bringing the total number of species to eight, which are keyed and described, complete with nomenclature and type citations. 相似文献
20.
A genetic transformation system has been developed for callus cells of Crataegus
aronia using Agrobacterium
tumefaciens. Callus culture was established from internodal stem segments incubated on Murashige and Skoog (MS) medium supplemented with
5 mg l−1 Indole-3-butyric acid (IBA) and 0.5 mg l−1 6-benzyladenine (BA). In order to optimize the callus culture system with respect to callus growth and coloration, different
types and concentrations of plant growth regulators were tested. Results indicated that the best average fresh weight of red
colored callus was obtained on MS medium supplemented with 2 mg l−1 2,4-dichlorophenoxyacetic acid (2,4-D) and 1.5 mg l−1 kinetin (Kin) (callus maintenance medium). Callus cells were co-cultivated with Agrobacterium harboring the binary plasmid pCAMBIA1302 carrying the mgfp5 and hygromycin phosphotransferase (hptII) genes conferring green fluorescent protein (GFP) activity and hygromycin resistance, respectively. Putative transgenic calli
were obtained 4 weeks after incubation of the co-cultivated explants onto maintenance medium supplemented with 50 mg l−1 hygromycin. Molecular analysis confirmed the integration of the transgenes in transformed callus. To our knowledge, this
is the first time to report an Agrobacterium-mediated transformation system in Crataegus
aronia. 相似文献