scholarly journals PH1: An Archaeovirus ofHaloarcula hispanicaRelated to SH1 and HHIV-2

Archaea ◽  
2013 ◽  
Vol 2013 ◽  
pp. 1-17 ◽  
Author(s):  
Kate Porter ◽  
Sen-Lin Tang ◽  
Chung-Pin Chen ◽  
Pei-Wen Chiang ◽  
Mei-Jhu Hong ◽  
...  
Keyword(s):  
Salt Lake ◽  
Burst Size ◽  
Growth Conditions ◽  
Single Step ◽  
Linear Dsdna ◽  
Step Growth ◽  
Terminal Proteins ◽  
Relationship Of ◽  
Haloarcula Hispanica ◽  
The Relationship

Halovirus PH1 infectsHaloarcula hispanicaand was isolated from an Australian salt lake. The burst size in single-step growth conditions was 50–100 PFU/cell, but cell density did not decrease until well after the rise (4–6 hr p.i.), indicating that the virus could exit without cell lysis. Virions were round, 51 nm in diameter, displayed a layered capsid structure, and were sensitive to chloroform and lowered salt concentration. The genome is linear dsDNA, 28,064 bp in length, with 337 bp terminal repeats and terminal proteins, and could transfect haloarchaeal species belonging to five different genera. The genome is predicted to carry 49 ORFs, including those for structural proteins, several of which were identified by mass spectroscopy. The close similarity of PH1 to SH1 (74% nucleotide identity) allowed a detailed description and analysis of the differences (divergent regions) between the two genomes, including the detection of repeat-mediated deletions. The relationship of SH1-like and pleolipoviruses to previously described genomic loci of virus and plasmid-related elements (ViPREs) of haloarchaea revealed an extensive level of recombination between the known haloviruses. PH1 is a member of the same virus group as SH1 and HHIV-2, and we propose the namehalosphaerovirusto accommodate these viruses.

The relationship of skin follicle development to growth rate in sheep.

1955 ◽  
Vol 6 (2) ◽  
pp. 308 ◽  
Author(s):  
PG Schinckel
Keyword(s):  
Growth Rate ◽  
Birth Weight ◽  
Growth Conditions ◽  
Considerable Importance ◽  
Follicle Development ◽  
Factors Affecting ◽  
Relationship Of ◽  
The Relationship

Observations are reported on factors affecting the ratio of secondary to primary follicles (SJP) in a flock of Merino sheep.It was found that all follicles were initiated prior to birth but that the number which finally came to maturity (production of fibre) was significantly affected by birth weight and growth from birth to 1 month. Growth at later ages appeared to be unimportant. There was a significant correlation (r = +0.29) between birth weight and log potential S/P at birth. This is interpreted to indicate that while pre-natal growth conditions affect the number of follicles initiated, other factors are also of considerable importance. It is concluded that the larger animals at birth also have a greater total number of primary follicles than smaller animals. It is further concluded that this difference in total primary follicles results primarily from differences in size a t the 90th day of pre-natal life rather than from differences in density a t that time.

The Relationship of Growth Conditions to Structural Defects of LPE-ALXGa1-XSb

1991 ◽  
Vol 38-41 ◽  
pp. 917-922 ◽  
Author(s):  
Naritaka Kitamura ◽  
K. Higuchi ◽  
Masaya Ichimura ◽  
A. Usami ◽  
T. Wada
Keyword(s):  
Growth Conditions ◽  
Structural Defects ◽  
Relationship Of ◽  
The Relationship

Isolation and partial characterization of a bacteriophage active on Hyphomicrobium sp. WI-926

1988 ◽  
Vol 34 (2) ◽  
pp. 101-106 ◽  
Author(s):  
W. C. Preissner ◽  
S. Maier ◽  
H. Völker ◽  
P. Hirsch
Keyword(s):  
Burst Size ◽  
Soft Agar ◽  
Single Step ◽  
Gram Positive Bacteria ◽  
Daughter Cells ◽  
Phage Adsorption ◽  
Individual Host ◽  
Filtration Enrichment ◽  
Phage Multiplication ◽  
Step Growth

Isolation of a Hyphomicrobium phage from raw sewage from Athens, Ohio, was achieved by a combination of differential centrifugation, filtration, enrichment in mixed Hyphomicrobium cultures, and purification on individual host strains by subculturing single plaques in soft agar overlayers. Enrichments with water from Lake Erie and Lake Beechwood (Ohio) were unsuccessful. Out of 21 Hyphomicrobium strains and 22 other Gram-negative and Gram-positive bacteria tested, only Hyphomicrobium WI-926 (isolated from a German forest pond) was susceptible. This phage had an isometric head (diameter between opposite apices, 67 nm) and a short (12 nm), noncontractile tail and belongs thus to the morphogroup C1. It contained double-stranded DNA. The single-step growth curve showed a latent period of 9 h, a rise period of 6 h, and a burst size of 35. The various differentiation stages in the host development exhibited different affinities for phage adsorption and development. While all stages allowed phage adsorption, the daughter cells were most efficient. Phage multiplication was limited to daughter cells, and the development of infected swarmer cells was arrested permanently at this stage.

Relationship of the Escherichia coli TrkA System of Potassium Ion Uptake with the F0F1-ATPase Under Growth Conditions Without Anaerobic or Aerobic Respiration

1998 ◽  
Vol 18 (3) ◽  
pp. 143-154 ◽  
Author(s):  
Armen Trchounian ◽  
Yelena Ohanjanyan ◽  
Karine Bagramyan ◽  
Vitya Vardanian ◽  
Eleonora Zakharyan ◽  
...  
Keyword(s):  
Escherichia Coli ◽  
Growth Conditions ◽  
Transport Systems ◽  
Aerobic Respiration ◽  
Anaerobic Conditions ◽  
Intact Cells ◽  
Potassium Ion Uptake ◽  
Relationship Of ◽  
The Relationship

K+ uptake by the Escherichia coli TrkA system is unusual in that it requires both ATP and ΔμH; a relation withH+ circulation through the membrane is thereforesuggested. The relationship of this system with the F0F1-ATPase was studied in intact cells grownunder different conditions. A significant increase of the N,N'-dicyclohexylcarbodiimide(DCCD)-inhibitedH+ efflux through the F0F1 by 5 mMK+, but not by Na+ added into thepotassium-free medium was revealed only in fermenting wild-type orparent cells, that were grown under anaerobic conditions withoutanaerobic or aerobic respiration and with the production of H2. Such an increase disappeared in the Δunc or the trkA mutants that have alteredF0F1 or defective TrkA, respectively. This finding indicates a closed relationship between TrkA andF0F1, with these transport systems beingassociated in a single mechanism that functions as an ATP-driven H+–K+-exchanging pump. ADCCD-inhibited H+–K+-exchangethrough these systems with the fixed stoichiometry of H+and K+ fluxes(2H+/K+) and a higherK+ gradient between the cytoplasm and the externalmedium were also found in these bacteria. They were not observed incells cultured under anaerobic conditions in the presence of nitrate orunder aerobic conditions with respiration and without production of H2. The role of anaerobic or aerobic respiration as adeterminant of the relationship of the TrkA with the F0F1 is postulated. Moreover, an increase of DCCD-inhibited H+ efflux by added K+, aswell as the characteristics of DCCD-sensitiveH+–K+-exchange found in a parentstrain, were lost in the arcA mutant with a defective Arc system, suggesting a repression of enzymes in respiratorypathways. In addition, K+ influx in the latest mutantwas not markedly changed by valinomycin or with temperature. The arcA gene product or the Arc system is proposed to beimplicated in the regulation of the relationship between TrkA and F0F1.

scholarly journals Characterization of Bacteriophage against Enterococcus faecium Resistant to Vancomycin Isolated from Chicken Skin

2019 ◽  
pp. 1-14
Author(s):  
Hazzierah Syaffieqah An Nadiah Azlan ◽  
Muhajir Hamid ◽  
Adelene Ai-Lian Song
Keyword(s):  
Latent Period ◽  
Growth Kinetics ◽  
Enterococcus Faecium ◽  
Burst Size ◽  
Single Step ◽  
Vancomycin Resistant Enterococcus ◽  
Chicken Skin ◽  
Step Growth ◽  
Vancomycin Resistant ◽  
Faecium Strain

Aims: To characterize bacteriophages with strong in vitro lytic activity against vancomycin resistant Enterococcus faecium before testing on the chicken skin for their efficacy. Study Design: An experimental was carried out to characterize two isolated bacteriophages against Enterococcus faecium and test for their efficacy on chicken skin. Study Place: The study was carried out in Laboratory of Vaccine and Immunotherapeutics, Institue of Bioscience, Universiti Putra Malaysia in Selangor, which is the most populous state in Malaysia. Methodology: Two host specific lytic phages against vancomycin resistant Enterococcus faecium strain FM8, designated as FM8-P1 and FM8-P2 were physiological characterized. This includes determination of their adsorption rate, multiplicity of infection, and single step growth kinetics. The optimum pH and temperature for both bacteriophages activity were also determined before tested on chicken skin at 4°C and 25°C, which represent chiller and room temperature in poultry production line. Results: Based on the result of single-step growth kinetics, the latent period of FM8-P1 was 35 min with a burst size of 460 particles per infected cells, while FM8-P2 has a shorter latent period (20 min) but a smaller burst size of 60 particles. The highest adsorption rate for FM8-P1 was 83% and FM8-P2 was 90% at 2 min and 4 min respectively. Both bacteriophages also exihibited a wide range of pH and temperature for their activity. Conclusion: The specificity, lytic activity and stability of FM8-P1 and FM8-P2 emphasized their potential in effectively eliminating the vancomycin resistant Enterococcus faecium strain FM8. However, further works are required to validate their in situ reliability.

scholarly journals Characterization of Six Bacteriophages ofSerratia liquefaciens CP6 Isolated from the Sugar Beet Phytosphere

1999 ◽  
Vol 65 (5) ◽  
pp. 1959-1965 ◽  
Author(s):  
Kevin E. Ashelford ◽  
John C. Fry ◽  
Mark J. Bailey ◽  
Aaron R. Jeffries ◽  
Martin J. Day
Keyword(s):  
Sugar Beet ◽  
Burst Size ◽  
Single Step ◽  
The Other ◽  
Cross Hybridization ◽  
The Family ◽  
Step Growth ◽  
Natural Ecology ◽  
Changes Over Time

ABSTRACT Six phages (ΦCP6-1 to ΦCP6-6) that are commonly found in the phytosphere of sugar beet (Beta vulgaris var. Amethyst) were investigated, and their relative impacts on their host (Serratia liquefaciens CP6) were compared. There were fundamental differences between the two most abundant predators of CP6 (ΦCP6-1 and ΦCP6-4). Like ΦCP6-2 and ΦCP6-5, ΦCP6-1 belonged to the family Siphoviridae, while ΦCP6-4 exhibited the morphology of the family Podoviridae. The other phages were members of the family Myoviridae. DNA-DNA cross-hybridization revealed that ΦCP6-1 and ΦCP6-4 had little common DNA, although all of the other phages exhibited some genetic similarity. Like ΦCP6-2, ΦCP6-3, and ΦCP6-5, ΦCP6-1 was capable of forming a lysogenic association with its host, while ΦCP6-4 and ΦCP6-6 appeared to be entirely virulent. Single-step growth curve experiments revealed that ΦCP6-4 had a much shorter latent period and a smaller burst size than ΦCP6-1. Also, ΦCP6-1 could transduce a number of host chromosomal markers with transfer frequencies of 2.9 × 10−9 to 3.9 × 10−7, whereas ΦCP6-4 could not transduce S. liquefaciens CP6 genes. When viewed in the context of the strikingly different temporal niches of these phages, our data provide an insight into how bacteriophage interactions with their hosts might reflect the natural ecology of bacteriophages. Our data also illustrate how the potential for gene transfer changes over time in an environment that supports several different phages.

scholarly journals The yeast CCR4 protein is neither regulated by nor associated with the SPT6 and SPT10 proteins and forms a functionally distinct complex from that of the SNF/SWI transcription factors.

Genetics ◽  
1994 ◽  
Vol 138 (4) ◽  
pp. 1005-1013 ◽  
Author(s):  
C L Denis ◽  
M P Draper ◽  
H Y Liu ◽  
T Malvar ◽  
R C Vallari ◽  
...  
Keyword(s):  
Transcription Factors ◽  
Protein Expression ◽  
Growth Conditions ◽  
General Transcription Factors ◽  
Expression Control ◽  
Genes Expression ◽  
Fermentative Growth ◽  
Adh2 Promoter ◽  
Relationship Of ◽  
The Relationship

Abstract The CCR4 protein is specifically required for the increased transcription at the ADH2 locus resulting from mutations in the SPT10 (CRE1) and SPT6 (CRE2) genes and is also required for the expression of ADH2 and other genes under non-fermentative growth conditions. The mechanism by which mutations in CCR4 suppress defects in SPT10 and SPT6 was examined. The SPT10 and SPT6 genes were shown not to control CCR4 mRNA or protein expression nor did SPT10 and SPT6 proteins co-immuneprecipitate with CCR4. CCR4 association with two other proteins, 195 and 185 kDa in size, was unaffected by either spt10 or spt6 mutations. Also, the ability of CCR4 to activate transcription when fused to the LexA DNA binding domain was not specifically enhanced by defects in either SPT10 or SPT6. These results suggest that SPT10 and SPT6, in negatively regulating transcription at ADH2, act through a factor that requires CCR4 function, but do not regulate CCR4 expression, control its activity, physically interact with it, or affect its binding to other factors. The relationship of CCR4 to the group of general transcription factors, SNF2, SNF5, SNF6 and SWI1 and SWI3, which comprise a multisubunit complex required for ADH2 and other genes' expression, was also examined. CCR4 protein expression was not controlled by these factors nor did they co-immuneprecipitate or associate with CCR4. In addition, a ccr4 mutation had little effect on an ADH2 promoter alteration in contrast to the large effects displayed by mutations in SNF2 and SNF5. These data suggest that CCR4 acts by a separate mechanism from that used by the SNF/SWI general transcription factors in affecting gene expression.

The relationship of the scleractinian corals to the rugose corals

Paleobiology ◽  
1980 ◽  
Vol 6 (02) ◽  
pp. 146-160 ◽  
Author(s):  
William A. Oliver
Keyword(s):  
Critical Points ◽  
Scleractinian Corals ◽  
Convincing Evidence ◽  
Early Triassic ◽  
Rugose Corals ◽  
History Of ◽  
The Subject ◽  
Relationship Of ◽  
The Relationship ◽  
Biologic Factors

The Mesozoic-Cenozoic coral Order Scleractinia has been suggested to have originated or evolved (1) by direct descent from the Paleozoic Order Rugosa or (2) by the development of a skeleton in members of one of the anemone groups that probably have existed throughout Phanerozoic time. In spite of much work on the subject, advocates of the direct descent hypothesis have failed to find convincing evidence of this relationship. Critical points are:(1) Rugosan septal insertion is serial; Scleractinian insertion is cyclic; no intermediate stages have been demonstrated. Apparent intermediates are Scleractinia having bilateral cyclic insertion or teratological Rugosa.(2) There is convincing evidence that the skeletons of many Rugosa were calcitic and none are known to be or to have been aragonitic. In contrast, the skeletons of all living Scleractinia are aragonitic and there is evidence that fossil Scleractinia were aragonitic also. The mineralogic difference is almost certainly due to intrinsic biologic factors.(3) No early Triassic corals of either group are known. This fact is not compelling (by itself) but is important in connection with points 1 and 2, because, given direct descent, both changes took place during this only stage in the history of the two groups in which there are no known corals.

Skeletal elements of crinoid echinoderms: High-resolution structural and microanalytical results

1983 ◽  
Vol 41 ◽  
pp. 194-195
Author(s):  
D. F. Blake ◽  
L. F. Allard ◽  
D. R. Peacor
Keyword(s):  
High Resolution ◽  
Marine Invertebrates ◽  
Sea Urchins ◽  
Structural Features ◽  
Sea Stars ◽  
High Resolution Tem ◽  
Relationship Of ◽  
The Relationship ◽  
Insight Into

Echinodermata is a phylum of marine invertebrates which has been extant since Cambrian time (c.a. 500 m.y. before the present). Modern examples of echinoderms include sea urchins, sea stars, and sea lilies (crinoids). The endoskeletons of echinoderms are composed of plates or ossicles (Fig. 1) which are with few exceptions, porous, single crystals of high-magnesian calcite. Despite their single crystal nature, fracture surfaces do not exhibit the near-perfect {10.4} cleavage characteristic of inorganic calcite. This paradoxical mix of biogenic and inorganic features has prompted much recent work on echinoderm skeletal crystallography. Furthermore, fossil echinoderm hard parts comprise a volumetrically significant portion of some marine limestones sequences. The ultrastructural and microchemical characterization of modern skeletal material should lend insight into: 1). The nature of the biogenic processes involved, for example, the relationship of Mg heterogeneity to morphological and structural features in modern echinoderm material, and 2). The nature of the diagenetic changes undergone by their ancient, fossilized counterparts. In this study, high resolution TEM (HRTEM), high voltage TEM (HVTEM), and STEM microanalysis are used to characterize tha ultrastructural and microchemical composition of skeletal elements of the modern crinoid Neocrinus blakei.

Studies on Leukemogenic and Sarcomagenic Viruses

1970 ◽  
Vol 28 ◽  
pp. 156-157
Author(s):  
Leon Dmochowski
Keyword(s):  
Electron Microscopy ◽  
Electron Microscope ◽  
Morphological Properties ◽  
Mode Of Development ◽  
Relationship Of ◽  
The Relationship

Electron microscopy has proved to be an invaluable discipline in studies on the relationship of viruses to the origin of leukemia, sarcoma, and other types of tumors in animals and man. The successful cell-free transmission of leukemia and sarcoma in mice, rats, hamsters, and cats, interpreted as due to a virus or viruses, was proved to be due to a virus on the basis of electron microscope studies. These studies demonstrated that all the types of neoplasia in animals of the species examined are produced by a virus of certain characteristic morphological properties similar, if not identical, in the mode of development in all types of neoplasia in animals, as shown in Fig. 1.

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