Genes with expression levels correlating to drip loss prove association of their polymorphism with water holding capacity of pork

Six genes that were known to exhibit expression levels that are correlated to drip loss BVES, SLC3A2, ZDHHC5, CS, COQ9, and EGFR have been for candidate gene analysis. Based on in silico analysis SNPs were detected, confirmed by sequencing, and used for genotyping. The SNPs were genotyped in about 1,800 animals from six pig populations including commercial herds of Pietrain (PI) and German Landrace (DL), different commercial herds of Pietrain × (German Large White × German Landrace) (PIF1(a/b/c)), and one experimental F₂-population Duroc × Pietrain (DUPI). Comparative and genetic mapping established the location of BVES on SSC1, of SLC3A2 and ZDHHC5 on SSC2, of CS on SSC5, of COQ9 on SSC6 and of EGFR on SSC9, respectively, coinciding with QTL regions for carcass and meat quality traits. BVES, SLC3A2, and CS revealed association at least with drip loss and with several other measures of water holding capacity (WHC). Moreover, COQ9 and EGFR were associated with several meat quality traits such as meat color and/or thawing loss. This study reveals statistic evidence in addition to the functional relationship of these genes to WHC previously evidenced by expression analysis. This study reveals positional and genetic statistical evidence for a link of genetic variation at these loci or close to them and promotes those six candidate genes as functional and/or positional candidate genes for meat quality traits.     

Determination of the inorganic degradation products sulfate and sulfamate in the antiepileptic drug topiramate by capillary electrophoresis

A capillary electrophoresis (CE) method has been developed as an alternative method for the determination of the inorganic degradation products sulfate and sulfamate in topiramate drug product and drug substance, currently performed by ion chromatography. The anions are separated in a background electrolyte containing potassium chromate and boric acid, followed by indirect UV detection. By adding tetradecyltrimethylammonium bromide to the electrolyte, analysis is performed under co-electroosmotic flow conditions. Variations in injection volumes and migration times are compensated for by use of an internal standard. The validation of the method, which was performed according to ICH guidelines (International Conference on Harmonization of Technical Requirements for Registration of Pharmaceuticals for Human Use) [1], comprises specificity, accuracy, linearity, precision, sensitivity and robustness. In addition, the results of an actual tablet sample analysis obtained by this CE method are statistically shown to be in close agreement with those obtained by an ion chromatographic method.     

Red-breasted goose colonies on the Taimyr Peninsula: Factors responsible for the proximity of goose nests to nests of peregrine falcons,rough-legged buzzards,and snowy owls

Red-breasted goose colonies have been studied near Medusa Bay (73°21′N, 80°32′E), on the northwestern Taimyr Peninsula, and along the Agapa River (70°11′N, 86°15′E) down to its mouth (71°26′N, 89° 13′E), in the central Taimyr Peninsula. Red-breasted geese nesting near peregrine falcons are protected by the falcons from arctic foxes; however, they are sometimes attacked by the falcons themselves. In the colonies near peregrine falcon nests, the vast majority of goose nests were situated no farther than 100 m from the falcon nest. When food is abundant, falcons protect a larger area around their nest. The distance between the falcon nest and the surrounding goose nests is inversely related to the falcon’s activity. In years of higher falcon activity, falcons prevent red-breasted geese from nesting as close to their nest as in years of lower falcon activity. Additional stimuli are required for red-breasted geese to form colonies near rough-legged buzzard nests. The distance between snowy owl nests and red-breasted goose nests was smaller when arctic foxes were abundant than when they were scarce.     

EXO5-DNA structure and BLM interactions direct DNA resection critical for ATR-dependent replication restart

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Natural Occurrence of Left-Handed (Z) Regions in PM2 DNA

Abstract

Bacteriophage PM2 DNA, a ccc genome of high apparent superhelical density, contains left-handed (Z) regions as detected by competitive radioimmunoassay, agarose gel electrophoresis of DNA: antibody complexes and immunoelectron microscopy. The latter technique, in conjunction with partial blockage of restriction endonuclease sites by bound antibody, was used to map the left-handed regions along the DNA molecule. A cluster of four to five antibody molecules (approximately 25% of bound antibody) was located within map units 0.05–0.18 of the single Hpa II restriction site. Sequence analysis of part of this region showed the presence of several areas of high alternating purine-pyrimidine content. A strong correlation is observed between alternating pyrimidine-purine tracts of significant length and antibody binding sites.     

Spontaneous fusion of phosphatidylcholine small unilamellar vesicles in the fluid phase

Using a high-sensitivity differential scanning microcalorimeter capable of performing cooling scans, we have examined the phase behavior of small unilamellar vesicles (SUV) as a function of time of storage above their order-disorder phase transition. Vesicles composed of dipalmitoylphosphatidylcholine (DPPC) and dimyristoylphosphatidylcholine (DMPC) were examined. Cooling scans on fresh (5-7-h postsonication) samples revealed broad, relatively simple heat capacity peaks (peak temperatures: 19.9 degrees C for DMPC, 37.8 degrees C for DPPC) free of high-temperature spikes or shoulders. Subsequent heating scans displayed a sharp peak characteristic of previously described fusion products formed below the phase transition. SUV samples stored for 1 or more days above their phase transition displayed a moderately broad, high-temperature shoulder (23.8 degrees C for DMPC and 40.2 degrees C for DPPC) in the cooling profile. For DMPC, the enthalpy associated with this peak increased in a first-order fashion with time. Hydrolysis products were not detected until 12-20 days of storage. Both the rate and extent of shoulder appearance increased with temperature (k = 0.0017 h-1, fraction of total enthalpy = 0.1 at 36 degrees C; k = 0.0037 h-1, fraction = 0.2 at 42 degrees C). Freeze-fracture electron micrographs confirmed that an intermediate-sized vesicle population (diameters 400-500 A) appeared in SUV samples stored above their phase transition. Also, the trapped volume of DMPC SUV increased from 0.26 microL/mumol after 17 h of storage to 0.54 microL/mumol after storage for 16 days at 36 degrees C.(ABSTRACT TRUNCATED AT 250 WORDS)     

31P NMR saturation-transfer measurements in Saccharomyces cerevisiae: characterization of phosphate exchange reactions by iodoacetate and antimycin A inhibition

31P nuclear magnetic resonance (NMR) saturation-transfer (ST) techniques have been used to measure steady-state flows through phosphate-adenosine 5'-triphosphate (ATP) exchange reactions in glucose-grown derepressed yeast. Our results have revealed that the reactions catalyzed by glyceraldehyde-3-phosphate dehydrogenase/phosphoglycerate kinase (GAPDH/PGK) and by the mitochondrial ATPase contribute to the observed ST. Contributions from these reactions were evaluated by performing ST studies under various metabolic conditions in the presence and absence of either iodoacetate, a specific inhibitor of GAPDH, or the respiratory chain inhibitor antimycin A. Intracellular phosphate (Pi) longitudinal relaxation times were determined by performing inversion recovery experiments during steady-state ATP gamma saturation and were used in combination with ST data to determine Pi consumption rates. 13C NMR and O2 electrode measurements were also conducted to monitor changes in rates of glucose consumption and O2 consumption, respectively, under the various metabolic conditions examined. Our results suggest that GAPDH/PGK-catalyzed Pi-ATP exchange is responsible for antimycin-resistant saturation transfer observed in anaerobic and aerobic glucose-fed yeast. Kinetics through GAPDH/PGK were found to depend on metabolic conditions. The coupled system appears to operate in a unidirectional manner during anaerobic glucose metabolism and bidirectionally when the cells are respiring on exogenously supplied ethanol. Additionally, mitochondrial ATPase activity appears to be responsible for the transfer observed in iodoacetate-treated aerobic cells supplied with either glucose or ethanol, with synthesis of ATP occurring unidirectionally.     

Regulation of enterochelin synthetase in Escherichia coli K-12

Enterochelin synthetase activity is controlled by both repression and feed-back inhibition mechanisms. Inclusion of iron in growth media results in synthesis of all four (D, E, F and G) components of enterochelin synthetase being repressed. The specific inhibition of L-serine activation (partial reaction catalyzed by the F component) by the end products, ferric-enterochelin and 2,3-dihydroxybenzoylserine, is shown to inhibit overall enterochelin synthetase activity.