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1.
Identification of Culturable Oligotrophic Bacteria within Naturally Occurring Bacterioplankton Communities of the Ligurian Sea by 16S rRNA Sequencing and Probing 总被引:10,自引:0,他引:10
L. Giuliano M. De Domenico E. De Domenico M.G. Höfle M.M. Yakimov 《Microbial ecology》1999,37(2):77-85
Abstract
Typical marine bacteria (i.e., obligately oligotrophic) that were numerically dominant members of naturally occurring marine
communities were identified by cloning and sequencing the amplified 16S rRNA genes obtained from dilution cultures of the
original samples. The data reported here refer to two different habitats of a marine pelagic environment (28 miles offshore,
in the northwestern Mediterranean Sea). The samples were taken from the water column at two representative layers, i.e., the
30-m depth, corresponding to the chlorophyll maximum layer, and the 1800-m depth, representative of a deep, oligotrophic environment.
Three major lineages were found in the 16S rDNA clone libraries prepared from the two samples, two of which could be assigned
to the Vibrio and the Rhodobacter groups. The third lineage was a distant relative of the genus Flavobacterium, but it was not closely related to any marine isolate. Six oligonucleotide probes, either complementary to the conserved sequence
domains or selectively hybridizing to the clone sequences, were designed for use as hybridization group-specific and strain-specific
probes. A single-mismatch discrimination between certain probes and nontarget sequences was demonstrated by detecting the
probes' specificity at different hybridization and washing conditions. The screening of the clone libraries with the obtained
probes revealed that neither the 30-m sample higher dilution nor the 1800-m one were pure cultures. While some representatives
of the Vibrio group were found in both the surface and the deep sample, the members of the Flavobacterium and Rhodobacter lineages were detected only in the deep and the euphotic layers, respectively. We suggest an approach for analyzing autochthonous
marine bacteria able to grow in unamended seawater.
Received: 19 May 1998; Accepted: 29 October 1998 相似文献
2.
F. Giuliano K. Mac Kenna S. Droupy O. Rampin V. Izard G. Benoit A. Jardin 《Andrologie》1999,9(2):226-246
Seminal emission and sperm expulsion are under the control of both the sympathetic and parasympathetic outflows and also of the somatic innervation conveyed by the pudendal nerve. The 2 phases of ejaculation are reflexive with the reflexes handled at the thoraco-lumbar and sacral levels of the spinal cord. Such a spinal organization remains widely unknown. The role of various peripheral neurotransmitters has been evidenced including norepinephrine and acetylcholine and also peptidergic, purinergic i.e. ATP and nitric oxide. Stimulation of the seminal tract afferents play a crucial in the onset of ejaculatory mechanisms. Except for the dorsal nerve of the penis, there is a lack of information concerning these afferents. Several supraspinal centers i.e. hypothalamus, medial amygdala, pons and nucleus paragigantocellularis exert descending and ascending inhibitory and excitatory influences on spinal nuclei controlling emission and expulsion of sperm. Central neurotransmission responsible for this supraspinal control could involve serotonin, oxytocin and norepinephrine. In the light of the available anatomical and neurophysiological data, pathophysiological aspects of ejaculatory disorders are futher discussed. Premature ejaculation could be related to a periheral and central hypersentivity. Most of the other ejaculation abnormalities are likely mainly related to an impairment of the central mechanisms. 相似文献
3.
Cristina Cereda Emanuela Leoni Pamela Milani Orietta Pansarasa Giuliano Mazzini Stefania Guareschi Elena Alvisi Andrea Ghiroldi Luca Diamanti Stefano Bernuzzi Mauro Ceroni Emanuela Cova 《PloS one》2013,8(10)
Several lines of evidence support the hypothesis of a toxic role played by wild type SOD1 (WT-SOD1) in the pathogenesis of sporadic amyotrophic lateral sclerosis (SALS). In this study we investigated both distribution and expression profile of WT-SOD1 in leukocytes from 19 SALS patients and 17 healthy individuals. Immunofluorescence experiments by confocal microscopy showed that SOD1 accumulates in the nuclear compartment in a group of SALS subjects. These results were also confirmed by western blot carried out on soluble nuclear and cytoplasmic fractions, with increased nuclear SOD1 level (p<0.05). In addition, we observed the presence of cytoplasmic SOD1 aggregates in agreement with an increased amount of the protein recovered by the insoluble fraction. A further confirmation of the overall increased level of SOD1 has been obtained from single cells analysis using flow cytometry as cells from SALS patients showed an higher SOD1 protein content (p<0.05). These findings add further evidence to the hypothesis of an altered WT-SOD1 expression profile in peripheral blood mononuclear cells (PBMCs) from patients with ALS suggesting that WT-SOD1 species with different degrees of solubility could be involved in the pathogenesis of the disease. 相似文献
4.
Elia Pintus Silvia Sorbolini Andrea Albera Giustino Gaspa Corrado Dimauro Roberto Steri Gabriele Marras Nicolò P. P. Macciotta 《Animal genetics》2014,45(1):1-11
Selection is the major force affecting local levels of genetic variation in species. The availability of dense marker maps offers new opportunities for a detailed understanding of genetic diversity distribution across the animal genome. Over the last 50 years, cattle breeds have been subjected to intense artificial selection. Consequently, regions controlling traits of economic importance are expected to exhibit selection signatures. The fixation index (Fst) is an estimate of population differentiation, based on genetic polymorphism data, and it is calculated using the relationship between inbreeding and heterozygosity. In the present study, locally weighted scatterplot smoothing (LOWESS) regression and a control chart approach were used to investigate selection signatures in two cattle breeds with different production aptitudes (dairy and beef). Fst was calculated for 42 514 SNP marker loci distributed across the genome in 749 Italian Brown and 364 Piedmontese bulls. The statistical significance of Fst values was assessed using a control chart. The LOWESS technique was efficient in removing noise from the raw data and was able to highlight selection signatures in chromosomes known to harbour genes affecting dairy and beef traits. Examples include the peaks detected for BTA2 in the region where the myostatin gene is located and for BTA6 in the region harbouring the ABCG2 locus. Moreover, several loci not previously reported in cattle studies were detected. 相似文献
5.
P. A. Scolnik P. Hinton I. M. Greenblatt G. Giuliano M. R. Delanoy D. L. Spector D. Pollock 《Planta》1987,171(1):11-18
The tomato (Lycopersicon esculentum (L.) Mill.) ghost plant is a mutant of the San Marzano cultivar affected in carotenoid biosynthesis. ghost plants exhibit a variable pattern of pigment biosynthesis during development. Cotyledons are green but true leaves are white. Green sectors, which appear to be clonal in origin, are frequently observed in the white tissue. Because of the lack of photosynthesis ghost plants have a very low viability in soil. We have developed a strategy for propagating ghost plants that employs organ culture to generate variegated green-white plants which, supported by the photosynthetic green areas, develop in soil to almost wild-type size. These plants were used to analyze the pigment content of the different tissues observed during development and plastid ultrastructure. Cotyledons and green leaves contain both colored carotenoids and chlorophyll but only the colorless carotenoid phytoene accumulates in white leaves. the plastids in the white tissue of ghost leaves lack internal membrane structures but normal chloroplasts can be observed in the green areas. The chromoplasts of white fruits are also impaired in their ability to form thylakoid membranes. 相似文献
6.
Dario Cremaschi Giuliano Meyer Guido Bottà Carlo Rossetti 《The Journal of membrane biology》1987,95(3):219-228
Summary In the epithelium of rabbit gallbladder, in the nominal absence of bicarbonate, intracellular Cl– activity is about 25mm, about 4 times higher than intracellular Cl– activity at the electrochemical equilibrium. It is essentially not affected by 10–4
m acetazolamide and 10–4
m 4-acetamido-4-isothiocyanostilbene-2,2-disulfonate (SITS) even during prolonged exposures; it falls to the equilibrium value by removal of Na+ from the lumen without significant changes of the apical membrane potential difference. Both intracellular Cl– and Na+ activities are decreased by luminal treatment with 25mm SCN–; the initial rates of change are not significantly different. In addition, the initial rates of change of intracellular Cl– activity are not significantly different upon Na+ or Cl– entry block by the appropriate reduction of the concentration of either ion in the luminal solution. Luminal K+ removal or 10–5
m bumetanide do not affect intracellular Cl– and Na+ activities or Cl– influx through the apical membrane. It is concluded that in the absence of bicarbonate NaCl entry is entirely due to a Na+–Cl– symport on a single carrier which, at least under the conditions tested, does not cotransport K+. 相似文献
7.
Dario Cremaschi Giuliano Meyer Carlo Rossetti Guido Bottà Paola Palestini 《The Journal of membrane biology》1987,95(3):209-218
Summary Cl– influx at the luminal border of the epithelium of rabbit gallbladder was measured by 45-sec exposures to36Cl– and3H-sucrose (as extracellular marker). Its paracellular component was evaluated by the use of 25mm SCN– which immediately and completely inhibits Cl– entry into the cell. Cellular influx was equal to 16.7eq cm–2 hr–1 and decreased to 8.5eq cm–2 hr–1 upon removal of HCO
3
–
from the bathing media and by bubbling 100% O2 for 45 min. When HCO
3
–
was present, cellular influx was again about halved by the action of 10–4
m acetazolamide, 10–5 to 10–4
m furosemide, 10–5 to 10–4
m 4-acetamido-4-isothiocyanostilbene-2,2-disulfonate (SITS), 10–3
m amiloride. The effects of furosemide and SITS were tested at different concentrations of the inhibitor and with different exposure times: they were maximal at the concentrations reported above and nonadditive. In turn, the effects of amiloride and SITS were not additive. Acetazolamide reached its maximal action after an exposure of about 2 min. When exogenous HCO
3
–
was absent, the residual cellular influx was insensitive to acetazolamide, furosemide and SITS. When exogenous HCO
3
–
was present in the salines, Na+ removal from the mucosal side caused a slow decline of cellular Cl– influx; conversely, it immediately abolished cellular Cl– influx in the absence of HCO
3
–
. In conclusion, about 50% of cellular influx is sensitive to HCO
3
–
, inhibitable by SCN–, acetazolamide, furosemide, SITS and amiloride and furthermore slowly dependent on Na+. The residual cellular influx is insensitive to bicarbonate, inhibitable by SCN–, resistant to acetazolamide, furosemide, SITS and amiloride, and immediately dependent on Na+. Thus, about 50% of apical membrane NaCl influx appears to result from a Na+/H+ and Cl–/HCO
3
–
exchange, whereas the residual influx seems to be due to Na+–Cl– contranport on a single carrier. Whether both components are simultaneously present or the latter represents a cellular homeostatic counterreaction to the inhibition of the former is not clear. 相似文献
8.
Influence of Hydrocortisone on Chick Embryo Retina Development 总被引:1,自引:1,他引:0
Renza Vento Giuseppina D'Ancona Michela Giuliano Gennaro Taibi Giovanni Tesoriere 《Journal of neurochemistry》1987,48(6):1693-1698
Treatment of chick embryos in ovo with hydrocortisone-21-phosphate (a single dose of 150 micrograms) caused a marked reduction of retinal thymidine kinase activity 24 h later. The inhibitory effect was highest (65-70%) in 8-10-day-old embryos and declined with age, disappearing after day 15. It was accompanied by a reduction in thickness of the retinal layers. Adrenocorticotropic hormone (ACTH) treatment (10 micrograms daily for 2 days) also produced an age-dependent inhibitory effect on retinal thymidine kinase, whereas treatment with a single dose of 200 micrograms of metopirone, a compound that prevents the 11 beta-hydroxylation of steroid molecules in the adrenal glands, impeded the decrease in thymidine kinase activity that normally occurs in chick embryo retina after day 9 of development. In addition, metopirone prevented the inhibition exerted by ACTH on thymidine kinase activity but had no effect on the action of hydrocortisone. 相似文献
9.
Paola G. Andreis Piera Rebuffat Anna S. Belloni Giuliano Neri Letizia Cavallini Giuseppe Gottardo Giuseppina Mazzocchi Alberta Coi Ludwik K. Malendowicz Dr. Gastone G. Nussdorfer 《Cell and tissue research》1989,258(1):43-51
Summary The morphology and function of isolated inner (zona fasciculata/reticularis) adrenocortical cells of rats pretreated with ACTH for 3, 6, 9 or 12 days were investigated. ACTH treatment induced a notable time-dependent enhancement in the steroidogenic capacity (corticosterone production) and growth of inner cells. The volumes of cells, mitochondrial compartment, membrane space [the cellular space occupied by smooth endoplasmic reticulum (SER) membranes] and lipid-droplet compartment, as well as the surface area of mitochondrial cristae and SER tubules, were increased in relation to the duration of ACTH pretreatment, and showed a highly significant positive linear correlation with both basal and stimulated corticosterone production. The acute exposure of isolated cells to ACTH provoked a striking lipid-droplet depletion, the extent of which was linearly and positively correlated with stimulated corticosterone secretion. The hypertrophy of the mitochondrial compartment and SER are interpreted as the morphological counterpart of the enhanced steroidogenic capacity of inner adrenocortical cells, inasmuch as the enzymes of steroid synthesis are located in these two organelles, and it is well known that chronic ACTH exposure stimulates the de novo synthesis of many of them in vivo. The rise in the number of lipid droplets, in which cholesterol is stored, is interpreted as being due to the fact that, under chronic ACTH treatment, the processes leading to cholesterol accumulation in adrenocortical cells (exogenous uptake and endogenous synthesis) exceed those of its utilization in basal steroid secretion. Cholesterol accumulated in lipid droplets as a reserve material may be rapidly utilized after acute ACTH exposure to meet the needs of the enhanced steroidogenic capacity of adrenocortical cells. 相似文献
10.
In this study we examine the effect on the centrosomes of cold treatment of early Drosophila embryos. Prolonged cold treatment during the mitotic divisions which lead to the formation of the blastoderm causes arrest at metaphase of the nuclear divisions. When examined with immunofluorescence microscopy the mitotic spindles show marked pole splitting with the formation of supernumerary and irregularly sized centers, all able to nucleate microtubules. In embryos recovered for longer periods the additional organizing centers become ring-shaped and lose their nucleating properties. Cold treatment of embryos during the cellularization of the blastoderm results in marked fragmentation of the centrosomes, but nucleating capacity is preserved. Sometimes the centrioles come away from the pericentriolar material and their structure is seen to be modified. 相似文献