Nucleotide Sequence and Variation of IGF2 Gene Exon 6 in Bos Taurus and Bos Indicus Cattle

The major assumption of this study is that polymorphism of a gene could be used to investigate its allele-specific expression as well as its methylation and imprinting status. Therefore, the aim of this study was to analyze the polymorphism of the coding region of the bovine IGF2 gene and to determine the sequence of its gene exon 6 in Bos taurus and Bos indicus cattle. A single nucleotide “C” deletion/insertion polymorphism was found in both cattle subspecies and a G/T transversion (RFLP-MboII) in the Bos indicus IGF2 gene. A 407-bp fragment of bovine IGF2 exon 6 was sequenced and the sequences (including variable nucleotides) were deposited in the GenBank database. A comparative analysis was performed for this fragment from different species; 99.5% identity was found between Bos taurus and Bos indicus cattle.     

Computing fullerene encapsulation of non-metallic molecules: N2@C60 and NH3@C60

Some endohedral fullerenes have been considered as possible candidate species for molecular memories. Recently, the encapsulation inside the fullerene cages has been extended from atoms to small molecules, for example the nitrogen molecule was placed inside the fullerene cage. The observed N₂@C₆₀ endohedral is computed in the paper together with NH₃@C₆₀, which was not yet observed. The computations are based on structural optimizations using density-functional theory (DFT) methods. In the optimized structures, the analytical harmonic vibrational analysis was carried out and the encapsulation energetics were evaluated using the second order Møller-Plesset (MP2) perturbation treatment. The lowest-energy structure has the N₂ unit oriented towards a pair of parallel pentagons so that the complex exhibits D _5d symmetry. At the MP2 level, the encapsulation of N₂ into C₆₀ brings a potential energy gain of ? 9.3 kcal/mol while that for NH₃ is ? 5.2 kcal/mol. The entropy term is also evaluated, yielding the standard Gibbs-energy change at room temperature for the encapsulation of N₂ and NH₃ of ? 2.6 and 1.5 kcal/mol, respectively. Some computed structural and vibrational characteristics are also reported. Emerging broader landscape of future applications of such encapsulates in nanoscience and nantechnology is discussed.     

FROM MORE TO FEWER? TESTING AN ALLEGEDLY PERVASIVE TREND IN THE EVOLUTION OF MORPHOLOGICAL STRUCTURE

While evolutionary trends have long received much attention and have been widely disputed, new methods are now allowing the testing of directional hypotheses with increased rigor. Here, we test a general hypothesis about the way many kinds of discrete characters are thought to evolve, termed oligomerization. This is the tendency for serial structures (such as arthropod body and appendage segments) or armature (such as spines) to evolve primarily through loss and fusion. Focusing on the Crustacea, we use maximum likelihood methods to test for directional evolution in a large sample (> 500) of discrete traits, analyzed against molecular-based phylogenies. We find evidence for a significant trend toward trait loss, in accordance with the reduction principle. However, this trend is far from ubiquitous, with many characters exhibiting a reconstructed bias toward gains. These results suggest that caution must be used before drawing conclusions about which taxa are "primitive" or about the directionality of morphological shifts in the absence of phylogenetic analysis. Nevertheless, oligomerization-as a trend rather than a law-may be an important process that influences evolutionary trajectories from both morphological and functional perspectives.     

Multiplexed glycoproteomic analysis of glycosylation disorders by sequential yolk immunoglobulins immunoseparation and MALDI-TOF MS

This study applied yolk immunoglobulins immunoaffinity separation and MALDI-TOF MS for clinical proteomics of congenital disorders of glycosylation (CDG) and secondary glycosylation disorders [galactosemia and hereditary fructose intolerance (HFI)]. Serum transferrin (Tf) and alpha1-antitrypsin (AAT) that are markers for CDG, were purified sequentially to obtain high-quality MALDI mass spectra to differentiate single glycoforms of the native intact glycoproteins. The procedure was found feasible for the investigation of protein macroheterogeneity due to glycosylation site underoccupancy then ensuing the characterization of patients with CDG group I (N-glycan assembly disorders). Following PNGase F digestion of the purified glycoprotein, the characterization of protein microheterogeneity by N-glycan MS analysis was performed in a patient with CDG group II (processing disorders). CDG-Ia patients showed a typical profile of underglycosylation where the fully glycosylated glycoforms are always the most abundant present in plasma with lesser amounts of partially and unglycosylated glycoforms in this order. Galactosemia and HFI are potentially fatal diseases, which benefit from early diagnosis and prompt therapeutic intervention. In symptomatic patients with galactosemia and in those with HFI, MALDI MS of Tf and AAT depicts a hypoglycosylation profile with a significant increase of underglycosylated glycoforms that reverses by dietary treatment, representing a clue for diagnosis and treatment monitoring.     

Altering the orientation of proteins on self-assembled monolayers: a computational study

A combined computational docking-molecular dynamics study has been performed on a system consisting of cytochrome c protein and alkanethiol self-assembled monolayers of various geometries. The results suggest that the orientation of the protein on the surface may be controlled or altered by means of designing specific structural motifs on the surface. The proposed computational approach may be used as a fast and reliable tool to complement other theoretical and experimental techniques of exploring other protein-surface interfaces.     

Altering young tomato plant growth by nitrate and CO2 preserves the proportionate relation linking long-term organic-nitrogen accumulation to intercepted radiation

* A previously published model of crop nitrogen (N) status based on intercepted photosynthetically active radiation (R(i), mol per plant) suggested that plant organic N accumulation is related to R(i) by a constant ratio, defined hereafter as the radiation use efficiency for N (NRUE). The aim of this paper was to compare the effects of N nutrition and CO2 enrichment on NRUE and RUE (radiation use efficiency for biomass accumulation). * In three unrelated glasshouse experiments, tomato plants (Solanum lycopersicum) grown in hydroponics were fed for 28 d (exponential growth) with full solutions containing constant NO3(-) concentrations ([NO3(-)]) ranging from 0.05 to 15 mol m(-3), both under ambient or CO2-enriched (1000 microl l(-1)) air. * Each experiment comprised five harvests. Low [NO3(-)] (< 0.3 mol m(-3)) limited growth via leaf area (LA) restriction and decreased light interception. CO2 enrichment enhanced dry weight and LA. RUE was not affected by [NO3(-)], but increased under CO2-enriched air. By contrast, NRUE was not affected by [NO3(-)] or CO2 enrichment. * It is suggested that the radiation efficiency for organic N acquisition (NRUE) did not depend on C or N nutrition for young plants grown under unstressed conditions.     

Diversity of the Bialowieza Forest avifauna in space and time

The Biaowiea Forest (BF) is an extensive and relatively little changed forest complex on the Polish-Belarussian border. Data on the structure and diversity of its breeding avifauna have mostly been collected in primeval old-growth stands, preserved within the Biaowiea National Park (BNP). Mapping censuses repeated in space (plots, replicated in riverine, oak-lime-hornbeam and coniferous stands) and time (permanent plots, 28 years) reveal that the breeding bird assemblages are rich in species (29–52/season in a 25 to 33-ha plot), but of moderate overall density (40–120 pairs/10 ha). The latter is due to low, lower than in man-transformed areas, densities of the majority of particular species. Despite marked changes in vegetation structure, the composition of the breeding bird assemblage does not vary much across different primeval forest types, with a single breeding bird community inhabiting all of them, including treefall gaps. High richness of the BF avifauna stems from the Forests geographical locality, as well as from a high level of the primeval avifauna retention. Over 95% of the 135–140 pristine species still breed there. Especially species-rich groups are birds of prey, owls, woodpeckers and Sylvinae warblers. Bird communities in the BNP and primeval tropical rain forests share many features, suggesting that natural differences between temperate and tropical forests were less pronounced in the past. The combination of high species richness with low densities of individual species is probably a feature of all pristine forests, independent of climatic zone. The BF avifauna must once have been typical of the ancient European forests and it has become so exceptional chiefly because it has preserved most of its pristine features. The BF thus constitutes an indispensable reference site for future studies of woodland bird biology. To ensure its survival should become a priority. Commercial logging, taking place over 80% of the Polish BF part, severely changes the Forests structure and strongly affects the birds, especially species which depend on dead wood (Dendrocopos leucotos, Picoides tridactylus) and on old-growth stands. The small area protected as the BNP becomes an increasingly isolated island, in which preservation of the primeval forest features seems to be impossible. In order to retain them, it is necessary to protect the whole BF area.     

Role of calcium in the secretion of leptin from white adipocytes

The mechanism by which calcium regulates leptin secretion was studied in adipocytes isolated from rat white adipose tissue. Incubation of adipocytes in a medium containing glucose, but no calcium, markedly inhibited insulin-stimulated leptin secretion (ISLS) and synthesis, without affecting basal leptin secretion or lipolysis. However, when pyruvate was used as a substrate, ISLS was insensitive to the absence of calcium. Likewise, the stimulatory effects of insulin were completely prevented by phloretin, cytochalasin B, and W-13 (3 agents that interfere with early steps of glucose metabolism) in the presence of glucose, but not in the presence of pyruvate. Thus calcium appears to be specifically required for glucose utilization. On the other hand, (45)Ca uptake and leptin secretion were not affected by insulin or by inhibitors of L-type calcium channels. However, agents increasing plasma membrane permeability to calcium (high calcium concentrations, A-23187, and ATP) increased (45)Ca uptake and concomitantly inhibited ISLS. Similarly, release of endogenous calcium stores by thapsigargin inhibited ISLS in a dose-dependent manner. ATP, A-23187, calcium, and thapsigargin inhibited ISLS, even in the presence of pyruvate. These results show that 1) extracellular calcium is necessary for ISLS, mainly by affecting glucose uptake, 2) insulin does not affect extracellular calcium uptake, and 3) increasing cytosolic calcium by stimulating its uptake or its release from endogenous stores inhibits ISLS at a level independent of glucose metabolism. Thus calcium regulates leptin secretion from adipocytes in a manner that is markedly different from its role in the exocytosis of many other polypeptidic hormones.