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11.
Molecular characterization of a rotaviruslike virus isolated from striped bass (Morone saxatilis). 总被引:1,自引:1,他引:0
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S K Samal C P Dopazo T H McPhillips A Baya S B Mohanty F M Hetrick 《Journal of virology》1990,64(11):5235-5240
The characteristics of a rotaviruslike (SBR) virus isolated from striped bass (Morone saxatilis) were examined following purification of viruses from infected cell cultures. Virions had a double-layered capsid of icosahedral symmetry and a diameter of 75 nm. Purified viruses contained five polypeptides ranging in molecular mass from 130 to 35 kDa. None of the structural proteins were glycosylated. Treatment with EDTA did not remove the outer capsid. By using enzymes and a chaotropic agent, it was shown that VP5 was the most external polypeptide. The genome of SBR virus was composed of 11 segments of double-stranded RNA (dsRNA). The electrophoretic pattern of the dsRNA of SBR virus was different from that of reovirus type 1 (Lang) and rotavirus (SA11) dsRNA. The SBR virus was compared with reovirus type 1 and SA11 virus by RNA-RNA blot hybridization. There was no cross-hybridization between any of the genome segments of the SBR, reovirus type 1, or SA11 viruses. Antigenic comparison of SBR virus and SA11 virus by cross-immunoprecipitation and cross-immunofluorescence tests did not show any relationship. These results suggest that SBR virus could represent a new genus within the family Reoviridae. 相似文献
12.
13.
Addition of different concentrations of heavy metal ions (Hg2+, Cu2+, Ni2+ and Pb2+) inhibited the photosystem 2 catalyzed electron transport activity (H2O→p-benzo-quinone) of the cyanobacteriumSpirulina platensis. Hg2+ caused the inhibition in electron transport activity in very low concentrations compared to the other metal ions. Hg2+ at this low concentration specifically altered the spectral properties of phycocyanin of the phycobilisomes in the intact cells ofSpirulina, whereas other heavy metal ions were ineffective in this sense. 相似文献
14.
M D Mamedov H Hayashi H Wada P S Mohanty G C Papageorgiou N Murata 《FEBS letters》1991,294(3):271-274
Glycinebetaine (betaine), an osmoregulant in halophilic plants, stabilized the evolution of oxygen and the synthesis of ATP by thylakoid membranes from the cyanobacterium Synechocystis PCC6803 when it was present during the preparation and incubation of the thylakoid membranes. Moreover, betaine enhanced the evolution of oxygen and the synthesis of ATP when present during assays. When betaine at 1.0 M was present during the preparation of thylakoid membranes and during the measurement of activity, the rate of evolution of oxygen was equivalent to that of intact cells. 相似文献
15.
Artificial selection was carried out for high and low spontaneous male recombination values in D. ananassae for nine generations by using cu b se marker (second chromosome) and wild stocks which were free from heterozygous chromosome inversions. The mean crossing-over frequency of nine generations was 2.22, 0.70 and 1.20% in high, low and control lines respectively. The values of regression coefficient and realized heritability also indicated that male recombination was affected by selection. However, response to selection was more pronounced in high line as compared to low line. This provides evidence that spontaneous male crossing-over in D. ananassae is under polygenic control. 相似文献
16.
The dark-relaxation kinetics of variable fluorescence, Fv, in intact green leaves of Pisum stativum L. and Dolichos lablab L. were analyzed using modulated fluorometers. Fast (t1/2 = 1 s) and slow (t1/2 = 7–8 s) phases in fv dark-decay kinetics were observed; the rate and the relative contribution of each phase in total relaxation depended upon the fluence rate of the actinic light and the point in the induction curve at which the actinic light was switched off. The rate of the slow phase was accelerated markedly by illumination with far-red light; the slow phase was abolished by methyl viologen. The halftime of the fast phase of Fv dark decay decreased from 250 ms in dark-adapted leaves to 12–15 ms upon adaptation to red light which is absorbed by PSII. The analysis of the effect of far-red light, which is absorbed mainly by PSI, on Fv dark decay indicates that the slow phase develops when a fraction of QA
– (the primary stable electron acceptor of PSII) cannot transfer electrons to PSI because of limitation on the availability of P700+ (the primary electron donor of PSI). After prolonged illumination of dark-adapted leaves in red (PSII-absorbed) light, a transient. Fv rise appears which is prevented by far-red (PSI-absorbed) light. This transient fv rise reflects the accumulation of QA
– in the dark. The observation of this transient Fv rise even in the presence of the uncoupler carbonylcyanide m-chlorophenyl hydrazone (CCCP) indicates that a mechanism other than ATP-driven back-transfer of electrons to QA may be responsible for the phenomenon. It is suggested that the fast phase in Fv dark-decay kinetics represents the reoxidation of QA
– by the electron-transport chain to PSI, whereas the slow phase is likely to be related to the interaction of QA
– with the donor side of PSII.Abbreviations CCCP
carbonylcyanide m-chlorophenylhydrazone
- FO
initial fluorescence level
- Fv
variable fluorescence
- P700
primary electron donor of PSI
- PSI, II
photosystem I, II
- QA (QA
–) QB (QB
–)
primary and secondary stable electron acceptor of PSII in oxidized (reduced) state
Supported by grant B6.1/88 DST, Govt. of India. 相似文献
17.
Summary The effect of methallibure (ICI 33,828) on the pituitary-gonad and the pituitary-thyroid axes of the Indian garden lizard, Calotes versicolor was studied. Following administration of methallibure B2 (FSH) and B3 (ICSH) cells of the pars distalis exhibited significant alterations with concomitant changes in the seminiferous tubules, and in the interstitial cells and epididymis respectively. B1 (TSH) cells exhibited conspicuous hypertrophy and degranulation which was reflected in dramatic changes in thyroid morphology. The caudally localized acidophilic A1 (PRL) cells also showed hypertrophy, hyperplasia and intense granulation. The rostrally located A2 (STH) acidophils and the B4 (ACTH) cells were unaffected by the treatment. The possible mode of action of this drug is discussed in the light of available literature.Supported by a grant from the University Grants Commission of India. The generous supply of methallibure by Dr. A.L. Walpole of the Imperial Chemical Industries Limited, England, through Professor C.J. Dominic, Banaras Hindu University, is gratefully acknowledged 相似文献
18.
Aging induced changes in photosynthetic electron transport of detached barley leaves 总被引:2,自引:0,他引:2
Primary leaf segments of 11-day-old seedlings of barley (Hordtumvulgare L. cv IB 65) were floated on distilled water in darknessat 25°C to induce senescence. This stress induced agingbrings significant loss in the total content of pigments, proteinsand nucleic acids (DNA, RNA) of the leaves and of chloroplastsisolated from the senescing leaves. Of the three macromolecularcomponents, RNA content of theisolated chloroplasts was foundmost susceptible to stress-induced aging. Loss of DCPIP Hill activity of the isolated chloroplasts couldbe correlated, in a general way, with the loss of pigments,proteins and nucleic acids of the leaves and chloroplasts isolatedfrom them. However, during the stress period, the ability ofdifferent exogenous electron donors like MnCl2 and diphenylcarbazide(DPC) to feed electrons to Photo System II (PS II) was foundto be different. MnCl2 supported photoreduction of DCPIP onlyup to the fourth day, whereas DPC sustained its ability to donateelectrons up to the seventh day of incubation of the leavesin darkness. These results suggest a sequential alteration ofthe sites in the electron-transport chain between H2O and PSII reaction centers of chloroplasts during dark-induced senescence.Kinetin not only prevented the loss of pigments and proteinsduring senescence, but also preserved the integrity of the electron-transportchain. (Received November 15, 1975; ) 相似文献
19.
A simple and sensitive approach for detection of malarial parasite in blood samples is demonstrated. The approach exploits our finding that, in hypertonic buffer, a normal red blood cell (RBC) rotates by itself when trapped by an optical tweezers. The rotational speed increases linearly at lower trap-beam powers and more rapidly at higher powers. In contrast, under the same experimental conditions, RBC having a malarial parasite does not rotate. The rotational speeds of other RBCs from malaria-infected sample are of an order of magnitude less than that for normal RBC and also increase much more slowly with an increase in trap beam power than that for normal RBC. The difference in rotational speeds could be exploited for the diagnosis of malaria. 相似文献
20.
Mohd Zeeshan Ansari Jyoti Sharma Rajesh S Gokhale Debasisa Mohanty 《BMC bioinformatics》2008,9(1):454