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PubMed1988

The repressor gene (c) of the Streptomyces temperate phage phi c31: nucleotide sequence, analysis and functional cloning.

The nucleotide sequence of the 3.4 kb SphI-G fragment that contained the repressor gene (c) of the temperate Streptomyces phage phi c31 was determined. Analysis of this sequence revealed a large open reading frame with protein coding character and sequence changes in c gene point and deletion mutants identified this as the coding region of the repressor. Two of the mutants studied had undergone deletions of 1.1 kb and 1.4 kb that had occurred across short direct repeats of 6 bp and 11 bp, respectively. Coupled in vitro transcription-translation experiments using the cloned SphI-G fragment and Streptomyces lividans cell free extracts identified a protein product of approximately 72 kDa, in close agreement with that predicted from the nucleotide sequence. A strongly predicted helix-turn-helix motif that may be involved in DNA binding occurred towards the carboxy-terminus of the amino acid sequence. Initial attempts to clone the SphI-G fragment in Streptomyces failed; using information gained from the sequence analysis a smaller segment of this DNA fragment was cloned in S. lividans and conferred immunity to a clear plaque mutant (c1) of phi c31.

Bacteriophages↗
PubMed1987

Evaluation of a temperate environment test to predict heat tolerance.

A temperate environment heat tolerance test (HTT) was formerly reported (Shvartz et al. 1977b) to distinguish heat acclimatized humans from former heat stroke patients. The purpose of this investigation was to evaluate the ability of HTT to measure acute individual changes in the HR and Tre responses of normal subjects, induced by classical heat acclimation procedures, thereby assessing the utility and sensitivity of HTT as a heat tolerance screening procedure. On day 1, 14 healthy males performed HTT (23.2 +/- 0.5 degrees C db, 14.9 +/- 0.5 degrees C wb) by bench stepping (30 cm high, 27 steps x min-1) for 15 min at 67 +/- 3% VO2max. On days 2-9, all subjects underwent heat acclimation (41.2 +/- 0.3 degrees C db, 28.4 +/- 0.3 degrees C wb) via treadmill exercise. Heat acclimation trials (identical on days 2 and 9) resulted in significant decreases in HR (170 +/- 3 vs 144 +/- 5 beats x min-1), Tre (39.21 +/- 0.09 vs 38.56 +/- 0.17 degrees C), and ratings of perceived exertion; plasma volume expanded 5.2 +/- 1.7%. On day 10, subjects repeated HTT; day 1 vs day 10 HR were statistically similar (143 +/- 6 vs 137 +/- 6 beats x min-1, p greater than 0.05) but Tre decreased significantly (37.7 +/- 0.1 vs 37.5 +/- 0.1 degrees C, p less than 0.05). Group mean HTT composite score (day 1 vs day 10) was unchanged (63 +/- 5 vs 72 +/- 6, p greater than 0.05), and individual composite scores indicated that HTT did not accurately measure HR and Tre trends at 41.2 +/- degrees C in 6 out of 14 subjects.(ABSTRACT TRUNCATED AT 250 WORDS)

Acclimatization↗
PubMed1985

The temperate B. subtilis phage phi 105 genome contains at least two distinct regions encoding superinfection immunity.

Two different PstI fragments of temperate phage phi 105 DNA are shown to confer superinfection immunity upon Bacillus subtilis when inserted into the multicopy cloning vector pE194 cop-6. The 2.3 kb PstI fragment I is located almost entirely within EcoRI fragment F and encompasses a region previously known to encode a repressor. The other fragment, PstI-E (4.3 kb) maps inside the EcoRI-B fragment, and allows an explanation of the clear-plaque phenotype of the deletion mutant phi 105DII:6c. The two regions can be distinguished functionally, since only the PstI fragment I product interacts with a specific phi 105 promoter-operator site.

Bacillus subtilis↗
PubMed1983

The detailed physical map of the temperate phage 16-3 of Rhizobium meliloti 41.

Restriction cleavage maps for enzymes EcoRI, BamHI, PstI, PvuII, XbaI and EcoRV of Rhizobium meliloti temperate phage 16-3 have been established. Together with the earlier maps (HindIII, KpnI, HpaI, BglII) 98 restriction sites, 'evenly' distributed, have been mapped along the phage genome, including the so far unmarked silent region of the chromosome. All the restriction maps have been fitted to each other by computer optimalization. Beyond for conventional techniques a computer program (PMAP) for physical mapping of linear DNA has been employed which made the experimentation, in several cases, extremely efficient.

Bacteriophages↗
PubMed1981

Transduction in Streptomyces hygroscopicus mediated by the temperate bacteriophage SH10.

The temperate actinophage SH10 mediates generalized transduction in Streptomyces hygroscopicus at low frequency. The efficiency of transduction depends on the average phage input, age of outgrowing spores of the recipient and on the selective marker. The highest EOT was found for the auxotrophic mutants 21(phe-) and 5(try-) (4.2 x 10(-6) and 2.7 x 10(-6), respectively). Transduction of the thermosensitive mutant NG14-216 ts 35 was two orders of magnitude lower (2.5 x 10(-8)). The transductant colonies segregated into stable and unstable clones. Stable transductants were never found to be lysogenic for phage SH10.

Bacteriophages↗
PubMed1981

Relationship of serum guanase levels with economic characters in Zebu purebred and temperate x Zebu crossbred dairy cattle.

Serum guanase levels of Indian Zebu (Hariana) cattle and its crosses with different exotic levels of temperate breeds of dairy cattle were estimated in 527 animals, and their associations with economic characters were determined. The overall mean value of serum guanase level was 13.46 +/- 0.45 IU/ml of serum. An inverse relationship between the concentration of the enzyme and the frequency of cattle falling within a definite range was observed, as over 75% of the animals possessed 1 to 20 IU/ml of serum guanase. An analysis of variance revealed significant differences (P less than 0.01) in enzyme levels among different genetic groups under study. Hariana (Zebu) purebreds had significantly higher enzyme levels (19.60 +/- 1.85) than any of the crossbred groups, whose enzyme levels ranged from 8.99 +/- 1.41 in Red Dane F1 half-breds to 14.30 +/- 1.11 in Brown Swiss F1 half-breds. The correlation and regression coefficients were significantly positive for reproductive traits such as age at first service and age at first calving, and significantly negative for production traits such as lactation yield and lactation length. These results suggest that selection of dairy cattle based on low serum guanase levels might result in correlated improvements in dairy cattle productivity.

Aminohydrolases↗
PubMed1991

Tonality and perception: musical scales primed by excerpts from The Well-Tempered Clavier of J. S. Bach.

The psychological relevance of the musicians' concept of tonality was tested in the context of the music of J. S. Bach. Musically trained listeners were instructed to sing the musical scale that first came to mind immediately after hearing short excerpts from Preludes of J. S. Bach's The Well-Tempered Clavier. For each Prelude, the tonic (first note) and the mode (major or minor) of the scale produced were compared to the tonic and mode designated by Bach. Results indicated that listeners (1) often established the designated tonic and mode within the first four notes of the piece; (2) within the first four bars, often established tonalities different from that of the designated key, a tendency that increased by the eighth bar; and (3) reestablished the tonic in the last four bars. These observations validate, in general, music-theoretic assumptions about the listener's hearing of tonality, and raise issues regarding the salient relations that engage the cognitive structures underlying tonality perception.

Attention↗
PubMed1995

Genome homology and superinfection immunity between temperate and virulent Lactobacillus delbrueckii bacteriophages.

The presence of short homologous DNA segments along the genomes of the temperate phage mv4 and the virulent phages LL-H, LL-K and JCL1032 of Lactobacillus delbrueckii was demonstrated with Southern hybridizations. One of these segments, the 2,817 nt MIS element of phage mv4, was further characterized by nucleotide sequence analysis and by superinfection immunity studies.

Bacteriophages↗
PubMedDate not supplied

Characterization of a temperate actinophage, MPphiWR-1, capable of infecting Micromonospora purpurea ATCC 15835.

A temperate actinophage was isolated from soil using the gentamicin-producing microorganism, Micromonospora purpurea ATCC 15835 as host. The characterization of the phage represents the initial step in its development as a cloning vector. The phage isolated, MPphiWR-1, formed red- to purple-pigmented turbid plaques. Cells isolated from these plaques were resistant to superinfection with lytic mutants of MPphiWR-1. Southern blots of genomic DNA from a resistant culture showed that MPphiWR-1 integrated into the host genome. The phage was UV- or Mitomycin C-inducible. The integration, resistance to superinfection and inducibility indicated a lysogenic relationship with the host. Using MPphiE-RCPM, a lytic derivative, the phage host range was demonstrated to include members of three genera: one species each of Ampullariella and Catellatospora, and 12 species of Micromonospora. The phage belonged to Ackerman's B1 morphotype having an isometric head and a flexible noncontractile tail. The density of the phage was 1.525 g/cc. Restriction site mapping demonstrated that the phage DNA was 57.9 kb long and had cohesive ends. Using EDTA enrichment, viable mutants with deletions of at least 3.5 kb were isolated and mapped. Phage adsorption, sensitivities and plating efficiency were investigated. Non-liposome PEG-mediated transfection was demonstrated.

Adsorption↗
PubMed1989

Three new and bioactive icosanoids from the temperate red marine alga Farlowia mollis.

Three new dihydroxyicosanoids, 12(R),13(R)-dihydroxyicosa-5(Z),8(Z),10(E),14(Z)-tetraenoic acid, 12(R),13(R)-dihydroxyicosa-5(Z),8(Z),10(E),14(Z),17(Z)-pentaeno ic acid and 10(R*),11(R*)-dihydroxyoctadeca-6(Z),8(E),12(Z)-trienoic acid, have been isolated from a previously unstudied temperate red marine alga, Farlowia mollis (Cryptonemiales, Rhodophyta). The structures of these new metabolites have been deduced from detailed nuclear magnetic resonance and mass spectrometry analyses on stabilized diacetate-methyl esters and stereochemistry deduced by 1H NMR couplings and CD analysis of a dibenzoate derivative. Collectively, these new natural products modulate fMLP-induced superoxide anion generation in human neutrophils, inhibit the conversion of arachidonic acid to lipoxygenase products by human neutrophils, and inhibit the functioning of the dog kidney Na+/K+ ATPase.

12-Hydroxy-5,8,10,14-eicosatetraenoic Acid↗
PubMed1987

Two new icosapentaenoic acids from the temperate red seaweed Ptilota filicina J. Agardh.

Two new fatty acid metabolites, 5(Z),7(E),9(E),14(Z),17(Z)-icosapentaenoic acid and 5(E),7(E),9(E),14(Z),17(Z)-icosapentaenoic acid, have been isolated from the temperate red marine alga, Ptilota filicina (Ceramiales, Rhodophyta). The structures of these new compounds, isolated as their methyl ester derivatives, have been deduced from detailed 1H nuclear magnetic resonance (NMR), 13C NMR and 2D-NMR analyses as well as comparisons to known compounds.

Eicosapentaenoic Acid↗
PubMed2004

Ten new temperate bacteriophages of Citrobacter youngae.

In a cross-test, we examined 55 strains of Citrobacter youngae against each other as potential producers of temperate bacteriophages and as potential sensitive indicators for them. Ten strains (18.2 %) showed the production of phages. Seven different strain-specific spectra of activity (from 1 to 11 strains each) were found. Phage production by 6 strains was inducible with mitomycin C, in 4 strains it was not inducible. The plaques of the phages were more or less turbid, without a lytic halo, tiny to small, 0.2-1.3 mm in diameter. Using a polyclonal, specific anti-lambda serum, all 10 phages were found to be clearly distinct from E. coli lambda phage, the phage 31/47 showing the highest neutralization titre of all. Interspecific tests with 15 strains of 8 species of Enterobacteriaceae revealed not a single case of activity of Citrobacter phages towards any of them. Five phage-immune clones lysogenized with 5 of the phages kept their remaining phage sensitivity spectra, though extended by sensitivity to 1-3 phages; 2 of these strains acquired also sensitivity to phage lambda. The phages belong to the morphotypes of Myoviridae (6 phages) and Siphoviridae (4 phages), with head diameters of 51-58 nm and tail length of 97-173 nm. Three strains produced corpuscular bacteriocins.

Bacteriophage Typing↗
PubMed2000

Changes in human fasciolosis in a temperate area: about some observations over a 28-year period in central France.

A retrospective study of 616 patients affected by fasciolosis was carried out to determine the numerical fluctuations of this disease over time, the recruitment of patients, and the modes of infection in a cattle-rearing area under a temperate climate (region of Limousin, central France). The annual number of patients showed irregular fluctuations between 1955 and 1987, after which it showed subsequent decreases until 1998. Before 1980, 66.3% of the persons under study were living in villages, whereas the others inhabited larger towns. An inverse relationship was noted after 1981: 80.8% of the individuals lived in towns consisting of > 1,000 inhabitants, whereas only 19.2% resided in smaller villages. Watercress was the infection mode in 98% of persons, with infections being attributed to four watercress species before 1980 versus only two species of Nasturtium sp. after 1981. The 235 watercress beds investigated in this study were found to contain 1 or 2 Lymnaea species as follows: L. truncatula only (84% of watering places), L. glabra only (6.3%), and both species (6.3%). In the populations of L. truncatula, natural infections of snails with Fasciola hepatica were irregular and occurred up to six times over the 28-year period in the region of Limousin. According to the authors, the decrease in human cases and the changes in the recruitment of patients might be explained by the demographic movements that occurred over several decades in the region of Limousin, with the moving of younger age groups into towns.

Adolescent↗
PubMed1997

Transduction of antibiotic resistance markers among Actinobacillus actinomycetemcomitans strains by temperate bacteriophages Aa phi 23.

Actinobacillus actinomycetemcomitans (Aa) strain ST1 carries the tetracycline (Tc) resistance transposon Tn916 and the Aa phi ST1 prophage, which is closely related to temperate bacteriophage Aa phi 23. High titre phage preparations were obtained from this strain by mitomycin C induction and were used to transduce the TcR determinant to the TcS recipient strains ZIB1001 and ZIB1015 (MIC 2 micrograms Tc/ml). TcR transductants (MIC > or = 32 micrograms Tc/ml) were detected at frequencies of 3 x 10(-6) to 5 x 10(-8) per pfu. All TcR transductants examined contained the entire Tn916 inserted at several different locations within the Aa genome. They appear to have resulted from generalized transduction. In addition both bacteriophages, Aa phi 23 and Aa phi ST1, were capable of transducing the chloramphenicol (Cm) resistance marker of plasmid pKT210 (transduction frequencies of 2 x 10(-5) to 3 x 10(-7) per pfu) to the recipient strain ZIB1001 (MIC 8 micrograms Cm/ml). Eleven CmR ZIB1001 transductants (MIC > or = 100 micrograms Cm/ml) studied carried a plasmid indistinguishable from pKT210 by restriction analyses. In view of the high prevalence of this phage family, and the increasing use of tetracycline in periodontitis therapy, these findings may have clinical importance.

Aggregatibacter actinomycetemcomitans↗
PubMed2004

QTLs for branching, floret formation, and pre-flowering floret abortion of rice panicle in a temperate japonica x tropical japonica cross.

A large panicle with numerous florets is essential for improving rice ( Oryza sativa L.) yield. Rice panicle size is determined by such underlying morphogenetic processes as: (1) primary branch formation on the panicle axis; (2) floret formation on the primary branches (mainly determined by the secondary branch formation); and (3) pre-flowering abortion of florets in the panicle. We examined QTLs for these processes to understand how they are integrated into panicle size. We developed 106 backcross-inbred lines (BC1F4) from a cross between 'Akihikari' (a temperate japonica) and 'IRAT109' (a tropical japonica) and constructed a genetic map. One QTL detected on chromosome 2, with a large effect (R=0.30) on the number of florets per panicle, affected both primary branch formation on the panicle axis and floret formation on the primary branches. In addition, three QTLs that affect only one of these two processes were identified on chromosomes 4, 9, and 11, each having a subsidiary effect on the number of florets per panicle (R2=0.04-0.07). QTLs for pre-flowering floret abortion were detected at three different regions of the genome (chromosomes 1, 10, and 11). This is the first report on QTLs for pre-flowering floret abortion in grasses. The absence of a co-location between QTLs suggests that floret formation and abortion are not directly linked causally. These results demonstrate that studying the partitioning of panicle size into these underlying morphogenetic components would be helpful in understanding the complicated genetic control of panicle size.

Agriculture↗
PubMed2006

Mapping resistance to Southern rust in a tropical by temperate maize recombinant inbred topcross population.

Southern rust, caused by Puccinia polysora Underw, is a foliar disease that can severely reduce grain yield in maize (Zea mays L.). Major resistance genes exist, but their effectiveness can be limited in areas where P. polysora is multi-racial. General resistance could be achieved by combining quantitative and race-specific resistances. This would be desirable if the resistance alleles maintained resistance across environments while not increasing plant maturity. Recombinant inbred (RI) lines were derived from a cross between NC300, a temperate-adapted all-tropical line, and B104, an Iowa Stiff Stalk Synthetic line. The RI lines were topcrossed to the tester FR615 x FR697. The 143 topcrosses were scored for Southern rust in four environments. Time to flowering was measured in two environments. The RI lines were genotyped at 113 simple sequence repeat markers and quantitative trait loci (QTL) were mapped for both traits. The entry mean heritability estimate for Southern rust resistance was 0.93. A multiple interval mapping model, including four QTL, accounted for 88% of the variation among average disease ratings. A major QTL located on the short arm of chromosome 10, explained 83% of the phenotypic variation, with the NC300 allele carrying the resistance. Significant (P < 0.001), but relatively minor, topcross-by-environment interaction occurred for Southern rust, and resulted from the interaction of the major QTL with the environment. Maturity and Southern rust rating were slightly correlated, but QTL for the two traits did not co-localize. Resistance was simply inherited in this population and the major QTL is likely a dominant resistant gene that is independent of plant maturity.

Basidiomycota↗
PubMed2003

Temporal patterns in bacterial communities in three temperate lakes of different trophic status.

Despite considerable attention in recent years, the composition and dynamics of lake bacterial communities over annual time scales are poorly understood. This study used automated ribosomal intergenic spacer analysis (ARISA) to explore the patterns of change in lake bacterial communities in three temperate lakes over 2 consecutive years. The study lakes included a humic lake, an oligotrophic lake, and a eutrophic lake, and the epilimnetic bacterial communities were sampled every 2 weeks. The patterns of change in bacterial communities indicated that seasonal forces were important in structuring the behavior of the bacterial communities in each lake. All three lakes had relatively stable community composition in spring and fall, but summer changes were dramatic. Summertime variability was often characterized by recurrent drops in bacterial diversity. Specific ARISA fragments derived from these lakes were not constant among lakes or from year to year, and those fragments that did recur in lakes in different years did not exhibit the same seasonal pattern of recurrence. Nonetheless, seasonal patterns observed in 2000 were fairly successful predictors of the rate of change in bacterial communities and in the degree of autocorrelation of bacterial communities in 2001. Thus, seasonal forces may be important structuring elements of these systems as a whole even if they are uncoupled from the dynamics of the individual system components.

Bacteria↗