bluuebunny/crossref_metadata_2025_split huggingface dataset:
Communally breeding Bechstein's bats have a stable social system that is independent from the postglacial history and location of the populations
Authors: KERTH GERALD , PETROV BOYAN , CONTI ANDREJ , ANASTASOV DANIJELA , WEISHAAR MANFRED , GAZARYAN SUREN , JAQUIÉRY JULIE , KÖNIG BARBARA , PERRIN NICOLAS , BRUYNDONCKX NADIA 
Published: April 2008

AbstractInvestigating macro‐geographical genetic structures of animal populations is crucial to reconstruct population histories and to identify significant units for conservation. This approach may also provide information about the intraspecific flexibility of social systems. We investigated the history and current structure of a large number of populations in the communally breeding Bechstein's bat (Myotis bechsteinii). Our aim was to understand which factors shape the species’ social system over a large ecological and geographical range. Using sequence data from one coding and one noncoding mitochondrial DNA region, we identified the Balkan Peninsula as the main and probably only glacial refugium of the species in Europe. Sequence data also suggest the presence of a cryptic taxon in the Caucasus and Anatolia. In a second step, we used seven autosomal and two mitochondrial microsatellite loci to compare population structures inside and outside of the Balkan glacial refugium. Central European and Balkan populations both were more strongly differentiated for mitochondrial DNA than for nuclear DNA, had higher genetic diversities and lower levels of relatedness at swarming (mating) sites than in maternity (breeding) colonies, and showed more differentiation between colonies than between swarming sites. All these suggest that populations are shaped by strong female philopatry, male dispersal, and outbreeding throughout their European range. We conclude that Bechstein's bats have a stable social system that is independent from the postglacial history and location of the populations. Our findings have implications for the understanding of the benefits of sociality in female Bechstein's bats and for the conservation of this endangered species.
Mini‐III, a fourth class of RNase III catalyses maturation of the Bacillus subtilis 23S ribosomal RNA
Authors: Olmedo Gabriela , Guzmán Plinio 
Published: April 2008

SummaryRibonuclease III (RNase III) type of enzymes are double‐stranded RNA (dsRNA)‐specific endoribonucleases that have important roles in RNA maturation and mRNA decay. They are involved in processing precursors of ribosomal RNA (rRNA) in bacteria as well as precursors of short interfering RNAs (siRNAs) and microRNAs (miRNAs) in eukaryotes. RNase III proteins have been grouped in three major classes according to their domain organization. In this issue of Molecular Microbiology, Redko et al. identified a novel class of bacterial RNase III, named Mini‐III, consisting only of the RNase III catalytic domain and functioning in the maturation of the 23S rRNA in Bacillus subtilis. Its absence from proteobacteria reveals that this step is mechanistically different from the corresponding step in Escherichia coli. The fact that Mini‐III orthologues are present in unicellular photosynthetic eukaryotes and in plants opens new opportunities for functional studies of this type of RNases.
Fold and function of polypeptide transport‐associated domains responsible for delivering unfolded proteins to membranes
Authors: Knowles Timothy J. , Jeeves Mark , Bobat Saeeda , Dancea Felician , McClelland Darren , Palmer Tracy , Overduin Michael , Henderson Ian R. 
Published: April 2008

SummaryMembranes of Gram‐negative bacteria, mitochondria and chloroplasts receive and fold β‐barrel transmembrane proteins through the action of polypeptide transport‐associated (POTRA) domains. In Escherichia coli, folding substrates are inserted into the outer membrane by the essential protein YaeT, a prototypic Omp85 protein. Here, the articulation between tandem POTRA domains in solution is defined by nuclear magnetic resonance (NMR) spectroscopy, indicating an unprecedented juxtaposition. The novel solution orientations of all five POTRA domains are revealed by small‐angle X‐ray scattering of the entire 46 kDa periplasmic region. NMR titration studies show that strands from YaeT's canonical folding substrate, PhoE, bind non‐specifically along alternating sides of its mixed β sheets, thus providing an ideal platform for helping to fold nascent outer‐membrane proteins. Together, this provides the first structural model of how multiple POTRA domains recruit substrates from the periplasmic solution into the outer membrane.
Trypanosoma brucei BRCA2 acts in antigenic variation and has undergone a recent expansion in BRC repeat number that is important during homologous recombination
Authors: Hartley Claire L. , McCulloch Richard 
Published: April 2008

SummaryAntigenic variation in Trypanosoma brucei has selected for the evolution of a massive archive of silent Variant Surface Glycoprotein (VSG) genes, which are activated by recombination into specialized expression sites. Such VSG switching can occur at rates substantially higher than background mutation and is dependent on homologous recombination, a core DNA repair reaction. A key regulator of homologous recombination is BRCA2, a protein that binds RAD51, the enzyme responsible for DNA strand exchange. Here, we show that T. brucei BRCA2 has undergone a recent, striking expansion in the number of BRC repeats, a sequence element that mediates interaction with RAD51. T. brucei BRCA2 mutants are shown to be significantly impaired in antigenic variation and display genome instability. By generating BRCA2 variants with reduced BRC repeat numbers, we show that the BRC expansion is crucial in determining the efficiency of T. brucei homologous recombination and RAD51 localization. Remarkably, however, this appears not to be a major determinant of the activation of at least some VSG genes.
Lipid spirals in Bacillus subtilis and their role in cell division
Authors: Barák Imrich , Muchová Katarína , Wilkinson Anthony J. , O'Toole Peter J. , Pavlendová Nada 
Published: April 2008

SummaryThe fluid mosaic model of membrane structure has been revised in recent years as it has become evident that domains of different lipid composition are present in eukaryotic and prokaryotic cells. Using membrane binding fluorescent dyes, we demonstrate the presence of lipid spirals extending along the long axis of cells of the rod‐shaped bacterium Bacillus subtilis. These spiral structures are absent from cells in which the synthesis of phosphatidylglycerol is disrupted, suggesting an enrichment in anionic phospholipids. Green fluorescent protein fusions of the cell division protein MinD also form spiral structures and these were shown by fluorescence resonance energy transfer to be coincident with the lipid spirals. These data indicate a higher level of membrane lipid organization than previously observed and a primary role for lipid spirals in determining the site of cell division in bacterial cells.
Evolution of a new enzyme activity from the same motif fold
Authors: Leiman Petr G. , Molineux Ian J. 
Published: April 2008

SummaryThe host cell recognition protein of the Escherichia coli bacteriophage HK620 is a large homotrimeric tailspike that cleaves the O18A1 type O antigen. The crystal structure of HK620 tailspike determined in the apo and substrate‐bound form is reported by Barbirz et al. in this issue of Molecular Microbiology. Lacking detectable sequence similarity, the fold and overall organization of the HK620 tailspike are similar to those of the tailspikes of the related phages P22 and Sf6. The substrate‐binding site is intrasubunit in P22 and HK620 tailspikes, but intersubunit in Sf6, demonstrating how phages can adapt the same protein fold to recognize different substrates.
Co‐regulation of yeast purine and phosphate pathways in response to adenylic nucleotide variations
Authors: Gauthier Sébastien , Coulpier Fanny , Jourdren Laurent , Merle Michel , Beck Stefanie , Konrad Manfred , Daignan‐Fornier Bertrand , Pinson Benoît 
Published: April 2008

SummaryAdenylate kinase (Adk1p) is a pivotal enzyme in both energetic and adenylic nucleotide metabolisms. In this paper, using a transcriptomic analysis, we show that the lack of Adk1p strongly induced expression of the PHO and ADE genes involved in phosphate utilization and AMP de novo biosynthesis respectively. Isolation and characterization of adk1 point mutants affecting PHO5 expression revealed that all these mutations also severely affected Adk1p catalytic activity, as well as PHO84 and ADE1 transcription. Furthermore, overexpression of distantly related enzymes such as human adenylate kinase or yeast UMP kinase was sufficient to restore regulation. These results demonstrate that adenylate kinase catalytic activity is critical for proper regulation of the PHO and ADE pathways. We also establish that adk1 deletion and purine limitation have similar effects on both adenylic nucleotide pool and PHO84 or ADE17 expression. Finally, we show that, in the adk1 mutant, upregulation of ADE1 depends on synthesis of the previously described effector(s) (S)AICAR ((N‐succinyl)‐5‐aminoimidazol‐4‐carboxamide ribotide), while upregulation of PHO84 necessitates the Spl2p positive regulator. This work reveals that adenylic nucleotide availability is a key signal used by yeast to co‐ordinate phosphate utilization and purine synthesis.
Fine‐tuned growth phase control of dps, encoding a DNA protection protein, by FIS and H‐NS
Authors: Schnetz Karin 
Published: April 2008

SummaryDps, a ferritin‐like DNA‐binding protein, protects bacterial DNA against oxidative stress and hyper‐compacts the nucleoid into a crystalline‐like structure. In Escherichia coli, transcription of dps from a single promoter is directed by σS‐RNA polymerase in stationary phase and by σ70‐RNA polymerase in fast‐dividing cells exposed to oxidative stress. In this issue of Molecular Microbiology, Grainger and co‐workers demonstrate that the nucleoid‐associated proteins, FIS and H‐NS, control sigma factor selection at the dps promoter by a novel mechanism. The finding suggests a simple mechanism of growth phase control of Dps production and has implications for the response to oxidative stress by pathogenic enterobacteria.
A Bowman‐Birk type protease inhibitor is involved in the tolerance to salt stress in wheat
Authors: SHAN LEI , LI CUILING , CHEN FANG , ZHAO SHUANGYI , XIA GUANGMIN 
Published: April 2008

ABSTRACTA salt‐responsive gene WRSI5 was characterized from salt‐tolerant cultivar Shanrong No. 3 (SR3), an introgression line via asymmetric somatic hybrid between Triticum aestivum L. cv. Jinan177 (JN177) and Thinopyrum ponticum Podp. The peptide encoded by WRSI5 contains a Bowman‐Birk domain sharing a high level of sequence identity to monocotyledonous protease inhibitors. When expressed in vitro, the WRSI5 gene product exhibited trypsin, but not chymotrypsin inhibition. The expression level of WRSI5 was increased in SR3 roots exposed to salt, drought or oxidative stress. In situ hybridization showed that it is induced in the endodermal cells of the mature region of the SR3 root tip, with no signal detectable in the corresponding region of the salt‐susceptible cultivar JN177. SR3 has a higher selectivity for K+ over Na+, and therefore limits the transport of Na+ from the root to the shoot. When overexpressed in Arabidopsis thaliana, WRSI5 improves the ability of seedlings to grow on a medium containing 150 mm NaCl. We suggest that WRSI5 plays an important role in regulating the plant growth rate or long‐distance Na+ transport in SR3 plants exposed to salt stress.
Effect of Azolla on Irrigated Rice in Brazil
Authors: Gutbrod K. G. 
Published: April 2008

AbstractA 1‐year study was conducted in 1983/84 at 2 experimental sites in Brazil to determine the effect of Azolla green‐manure (AO), A. intercrop (OA) and their combination (AA) on rice yield in comparison to mineral fertilization with urea. Nitrogen sources were combined with 4 rice sowing/planting systems.On terraced terra‐roxa soil (Paleudalf) in subtropical northern Paraná State, transplanted rice (T) yielded 8.66 t · ha−1 compared to pregerminated (P), direct‐sown (D) and conventionally sown (C) rice with 7.92; 7.73 and 7.48 t · ha−1, respectively. N‐source treatments yielded 9.33; 8.54 and 7.34 t · ha−1 for AA, OA and AO compared to 8.46; 7.98 and 6.05 for 100, 50 and 0 kg N · ha−1, respectively. Fertilizer‐nitrogen equivalence (FNE) of Azolla treatments compared to urea broadcast in 3 applications ranged between 0 and more than 100 kg N · ha−1.On hydromorphic latosol (Ustic Dystropept) in tropical Goiás State, rice yields were 4.07; 2.52; 1.46 and. 1.33 t · ha−1 for systems T, P, C and D, respectively. N‐source treatments yielded 2.79; 1.98 and 1.78 t · ha−1 for AA, AO and OA compared to 3.43; 2.63 and 1.46 t · ha−1 for 60; 30 and 0 kg N · ha−1 as urea broadcast in 2 applications, respectively. FNE of Azolla was between 0 and 56 kg N · ha−1.
Analytical Solutions of the Transient State Oxygen Diffusion Equation in Soils With a Production Term
Authors: Kanwar R. S. 
Published: April 2008

AbstractAnalytical solutions were developed to describe the nonsteady‐state transport of oxygen from the atmosphere into the soil media. These analyses are based on diffusion theory for oxygen diffusion in soils when oxygen is being consumed, either at a constant rate or consumption rate varies with time due to the biological and chemical processes occurring continuously in the soil media. The transport equations, and the initial and boundary conditions are set up to represent a field situation. Analytical solutions are obtained to calculate transient oxygen concentrations in the soil profile. The quantity of oxygen that might diffuse into the soil from atmosphere at any time, t, also can be found by using this method. Comparison with published data is made, and reasonably good agreement is obtained between oxygen concentrations at different depths and times computed from the analytical solutions and those actually measured.
Response of Yield Attributes of Isogenic Tall, Semidwarf, and Doubledwarf Winter Wheats to Nitrogen Fertilizer and Seeding Rates
Authors: Kim Nam I. , Paulsen Gary M. 
Published: April 2008

AbstractRelationships between grain yield attributes and response to agronomic practices of dwarf and tall genotypes in the major U.S. wheat region were investigated. Isogenic tall, semidwarf, and doubledwarf (Norin 10/5/Pawnee) ‘Pawnee’ winter wheat (Triticum aestivum L.) lines were planted in a split‐split‐plot design with nitrogen fertilizer rates of 0, 50, and 100 kg ha−1 as main plots and seeding rates of 30, 60, and 90 kg ha−1 as subplots in four replications at Hutchinson and Manhattan, Kansas, during 1980–1981. There was no evidence that dwarf lines responded better than the tall line to nitrogen fertilizer; however, percentage fertile spikelets, spike length, harvest index, and kernel number per spike of the semidwarf line were favored by high nitrogen rates. Grain yield was more responsive to seeding rate in the doubledwarf line than in the other lines, and test weight and spike number per unit area were more responsive to seeding rate in one or both dwarf lines than in the tall line. Grain yield of each genotype depended highly on the predominant yield attributes — usually spike number per unit area and/or kernel weight — at one or both locations.
Effect of Soil Temperature on the Carbohydrate Status in the Potato Plant (S. tuberosum L.)
Authors: Randeni G. , Caesar K. 
Published: April 2008

AbstractSeed tubers of the variety Ostara were raised in growth chambers of 16°C air temperature continuously. The vessels were placed in a water bath of automatic temperature regulation so that soil temperatures of 16°C and 28°C could be maintained. Four weeks after emergence the plants were treated with 14CO2 and 24 hours later the plants were harvested. Three more treatments and time harvests followed in two weeks intervals. C‐14 activity was determined in soluble carbohydrates, in insoluble carbohydrates, and in non extractable residues respectively of the various plant parts in order to obtain information about the translocation of assimilates in the plant.While the plants at 28°C soil temperature reduced the soluble sugar levels to 50% up to 70 days after emergence, the plants at 16° brought it down to 33% much faster. — The C‐14 activity in insoluble carbohydrates amounted to only 50 % in the plants at 28°C while at 16°C it was more than 2/3 (Tables 1 and 2). — The C‐14 activity in non extractable residues is much less at 28°C than at 16°C (Tables 3 and 4). — The starch weight reaches only 30% of the value obtained at lower temperature 70 days after emergence (Table 5). — At the higher temperature starch is also increasingly transferred to the tubers but to a much lesser extent and not from the stems and stolons (Table 6).Possible causes, particularly the role of phytohormones, and consequences are discussed.
Effect of Cold Hardening on Growth and Essential Oil Content of Mentha piperita L.
Authors: El‐Moursi A. , Shedeed M. R. , Reda F. , El‐Din K. Gamal 
Published: April 2008

AbstractDivisions of running rhizomes of peppermint plants were planted in loamy clay soil in the experimental farm of National Research Centre, Dokki, Cairo, Egypt. After 21 days, the plants were exposed to low temperature 4, 7°C for 6, 9 and 12 days in controlled chamber before transplanting to large pots in winter season. Three cuttings were taken from the plants of different treatments during the season after 4, 7 and 10 months from transplanting. Representative samples of 6 replicates from each treatment were taken for the determination of vegetative growth and oil content in the leaves and branches.The results obtained indicated that the highest fresh and dry weight of leaves and branches was recorded in the second cutting, however, it markedly decreased in the third one. The highest favourable effect of cold hardening on vegetative growth was observed at 4°C for 12 days exposure in the second cutting. The percentage of volatile oil in the leaves recorded the highest values in treatment of 7°C for 6 days in the second sampling date. Cold hardening either at 4°C or 7°C resulted in pronounced increase in the essential oil yield produced by the plant with the superiority of 4°C for 12 days which recorded the highest value.It can be concluded from the obtained results that hardening peppermint plants with low temperature, particularly 4°C for 12 days before transplanting improved plant growth and considerably increased the volatile oil content in plant leaves and branches.
Genetic Variability, Genotypic and Phenotypic Correlations and Path‐Coefficient Analysis in Egyptian Clover (Trifolium alexandrinum L.)
Authors: Bakheit Bahy R. 
Published: April 2008

AbstractFifty‐six accessions of multi‐cut Egyptian clover were compared at four experiments under different environmental conditions; i.e. location and season. Considerable variation existed for all the characters studied. The genetic variance exceeded the environmental variance for all the studied traits. Heritability was high for all characters studied. The expected genetic advance from selection of the superior 10.7% of the accessions as calculated from the combined data reached to 16.10, 17.50, 5.20, 20.60, 3.52 and 21.00 for mean plant height, seasonal fresh forage yield, mean dry matter percentage, seasonal dry forage yield, mean protein percentage, and seasonal protein yield, respectively. Both phenotypic and genotypic correlations among traits showed that mean plant height was positively correlated with each of seasonal fresh forage yield, seasonal dry forage yield, mean dry matter percentage and seasonal protein yield, but negatively correlated with mean protein percentage. Negative correlation were also found between mean protein percentage with seasonal fresh and dry forage yield.Over all experiments, pat‐coefficient analysis revealed that seasonal fresh forage yield had the highest positive direct effect on seasonal protein yield (0.841), followed by mean dry matter percentage (0.461). The mean protein percentage showed the minimum direct (0.172) and indirect influence on seasonal protein yield.
Transport of Anion Towards Root as Influenced by Soil Compaction
Authors: Bhadoria P. B. S. 
Published: April 2008

AbstractThis experiment was conducted in metal container of 2 liters capacity in the glass house to find out the effect of different bulk densities on the movement of non‐adsorbed anion (Cl) towards the root. It is inferred from the study that at low moisture content, compaction to a certain degree can increase movement of nutrients to the root due to increase in moisture content per unit volume of soil, further increase in compaction may however affect nutrient availability to the roots. This has a far greater significance in No3 movement. But from the salinity point of view, plant roots in soil containing salt will be exposed to a much higher salt concentration than that may be obtained from the analysis of the bulk soil.
Relationship Between Digestibility of Bromus inermis Plant Parts
Authors: Ugherughe P. O. 
Published: April 2008

AbstractThe change in leaf to stem ratio with advancing maturity is perhaps the greatest contributing factor in forages to decreased nutritive value. However, the relationship between the digestibility of plant parts has not been determined in most forage grasses. The objective of this study was to investigate the relationship between digestibility of smooth bromegrass (Bromus inermis Leyss.) plant parts and that between them and whole plant digestibility. Thirty genotypes grown as solid stands and spaced plants were used for the study. The leaves, stems, panicles, and whole plants were evaluated for digestibility using the acid‐pepsin dry matter disappearance (APDMD) technique. Genotypes were significantly different in leaf, stem, and panicle APDMD in each cutting under the two planting patterns. Significant differences were also found among APDMD of the first cutting (APDMD‐1) of leaves, stems, panicles, and whole plants, respectively, over the two‐year period. The APDMD of leaves, stems, panicles, and whole plants were less variable in the second and third cuttings than in the first cutting. Among the plant parts, the APDMD of leaves correlated best with whole plant APDMD. Furthermore, leaf APDMD also correlated better with stem APDMD than with panicle APDMD. Useful regression equations for the prediction of whole plant APDMD from leaf APDMD were obtained.
Effect of Sowing Date and Weed Control on Grain Yield and its Components in Some Wheat Cultivars
Authors: Ibrahim A. F. , Kandil A.‐A. , El‐Hattab A. H. , Eissa A. K. 
Published: April 2008

I. AbstractThe influence of sowing dates (Oct. 21, Nov. 10, Nov. 30 and Dec. 21), weed control treatments using Brominal, Tribunil herbicides as compared to hand weeding and unweeded treatments on the yield performance of newly released spring wheat varieties (Sakha 8, Sakha 61 and Giza 157 was studied during 1980/81, 1981/82 and 1982/83 seasons. According to the combined analysis the results could be summarized as follows:

Sowing date had significant effect on grain yield and some other characters such as plant height, days to heading and maturity, weight of grains per spike and 1000‐grain weight. Highest grain yield was obtained when wheat was sown during Nov. Dry weight of weeds was not significantly affected by sowing date.
Differences between cultivars reached to the significant level in plant height, spike length, number of grains per spike and 1000‐grain weight.
Weed control treatments had significant effect on most studied traits. Grain yield was nearly the same when Tribunil (3.5 kg/ha), Brominal (2.4 1/ha) or hand weeding was used. Grain yield of unweed treatment decreased by 10.9%, 10.9% and 9.8% compared to the former treatments, respectively.
Data showed that Tribunil was more effective on both grassy and broad leaved weeds, however, Brominal was effective only on broad leaved.