Substrate moisture,particle size and temperature preferences of trap‐building larvae of sympatric antlions and wormlions from the rainforest of Borneo

1. Larvae of antlions (Neuroptera: Myrmeleontidae) and wormlions (Diptera: Vermileonidae) display a convergently evolved sit‐and‐wait hunting strategy of building pitfall traps in sandy areas. This study investigated a sympatric population of antlions and wormlions in the lowland rainforest of Borneo for substrate moisture, particle size and temperature preferences. It was hypothesised that these animals would show different preferences regarding these microhabitat traits. 2. The results showed that antlions had a higher aversion to moisture compared with wormlions, but that wormlions had a higher preference for small‐particle sand. Furthermore, thermal preferences in antlions and wormlions were significantly different, with antlions choosing higher temperatures. 3. The detected differences between antlions and wormlions might contribute to their niche partitioning in the mixed Bornean population and thus facilitate coexistence of these animals. It is possible that the hotter and dryer microhabitat edges are preferred by antlions.     

Combined effect of X‐ray radiation and static magnetic fields on reactive oxygen species in rat lymphocytes in vitro

The aim of this study was to investigate the effect of static magnetic fields (SMF) on reactive oxygen species induced by X‐ray radiation. The experiments were performed on lymphocytes from male albino Wistar rats. After exposure to 3 Gy X‐ray radiation (with a dose rate of 560 mGy/min) the measurement of intracellular reactive oxygen species in lymphocytes, using a fluorescent probe, was done before exposure to the SMF, and after 15 min, 1 and 2 h of exposure to the SMF or a corresponding incubation time. For SMF exposure, 0 mT (50 µT magnetic field induction opposite to the geomagnetic field) and 5 mT fields were chosen. The trend of SMF effects for 0 mT was always opposite that of 5 mT. The first one decreased the rate of fluorescence change, while the latter one increased it. Bioelectromagnetics 34:333–336, 2013. © 2012 Wiley Periodicals, Inc.     

Ectopic Expression of the Tetratricopeptide Repeat Domain of SPINDLY Causes Defects in Gibberellin Response

The SPINDLY (SPY) protein of Arabidopsis is a negative regulator of gibberellin (GA) response. The SPY protein has 10 copies of the tetratricopeptide repeat (TPR) at the N terminus. TPR motifs function as protein-protein interaction domains. Several spy alleles are affected only in the TPR region suggesting that protein-protein interactions mediated by this domain are important for proper GA signaling. We have used a reverse genetics approach to further investigate the role of the TPR domain. The TPR domain of SPY was overexpressed in wild-type, gai, and spy plants. Expression of the TPR domain alone is not sufficient to rescue spy mutants. Expression of the TPR domain in a wild-type background produces phenotypes similar to those caused by loss-of-function spy mutants including resistance to GA biosynthesis inhibitors, short hypocotyl length, and early flowering. The dwarfing of the floral shoot internodes caused by the gai mutation was suppressed by expression of the TRP domain. Expression of the TPR domain had no effect on the abundance of endogenous SPY mRNA. The TPR domain was found to interact with SPY both in vitro and in yeast two-hybrid assays. These data indicate that the TPR domain of SPY can participate in protein-protein interactions and that these interactions are important for the proper functioning of SPY.     

Analysis of the distribution and structure of integrated Banana streak virus DNA in a range of Musa cultivars

Banana streak virus strain OL (BSV-OL) commonly infects new Musa hybrids, and this infection is thought to arise de novo from integrated virus sequences present in the nuclear genome of the plant. Integrated DNA (Musa6+8 sequence) containing the whole genome of the virus has previously been cloned from cv. Obino l’Ewai (Musa AAB group), a parent of many of the hybrids. Using a Southern blot hybridization assay, we have examined the distribution and structure of integrated BSV-OL sequences in a range of Musa cultivars. For cv. Obino l’Ewai, almost every restriction fragment hybridizing to BSV-OL was predicted from the Musa6+8 sequence, suggesting that this is the predominant type of BSV-OL integrant in the genome. Furthermore, since only two junction fragments of Musa/BSV sequence were detected, and the Musa6+8 sequence is believed to be integrated as multiple copies in a tandem array, then the internal Musa spacer sequences must be highly conserved. Similarly sized restriction fragments were detected in four BB group cultivars, but not in six AA or AAA group cultivars, suggesting that the BSV-OL sequences are linked to the B-genome of Musa. We also provide evidence that cv. Williams (Musa AAA group) contains a distinct badnavirus integrant that is closely related to the ‘dead’ virus integrant previously characterized from Calcutta 4 (Musa acuminata ssp. burmannicoides). Our results suggest that the virus integrant from cv. Williams is linked to the A-genome, and the complexity of the hybridization patterns suggest multiple sites of integration and/or variation in sequence and structure of the integrants.     

Moniliformin,deoxynivalenol, 3Acetyldeoxynivalenol and zearalenone — Mycotoxins associated with corn cob fusariosis in Poland

An isolated rat liver was perfused with deoxynivalenol (DON) at a dose of 3 mg in a recirculating perfusion system. To identify glucuronide conjugates equal amounts of bile samples, perfusate and liver homogenates were incubated with and without (control) a β-glucuronidase preparation and analyzed by thin layer chromatography and capillary gas liquid chromatography — chemical ionization mass spectrometry. A total of 40.4% of the administered dose of DON was found to be conjugated with glucuronic acid (perfusate 20.4%, bile 19.2%, liver 0.8%), while only 1.3% of the parent DON (perfusate 1.1%, bile 0.2%) was detected. The cleavage of DON-glucuronide was demonstrated by incubating DON-glucuronide containing bile samples with intestine contents under anaerobic conditions.     

A new device to measure the structural properties of the femur-anterior cruciate ligament-tibia complex

Previous studies of biomechanical properties of femur-anterior cruciate ligament-tibia complex (FATC) utilized a wide variety of testing methodologies, particularly with respect to ligament orientation relative to loading direction. A new device was designed and built to test the anterior-posterior displacement of the intact porcine knee at 30 and 90 deg of flexion, as well as the tensile properties of the FATC at any loading direction and flexion angle. Tensile tests were performed with the knees at 30 and 90 deg of flexion with the loading direction along either the axis of the tibia (tibial axis) or the axis of the anterior cruciate ligament (ligament axis). The results showed that the stiffness, ultimate load and energy absorbed were all significantly increased when the FATC was tested along the ligament axis. This study demonstrates the importance of alignment in the evaluation of the biomechanical characteristics of the femur-ACL-tibia complex.     

Partial Purification and Characterization of Indol-3-Ylacetylglucosemyo-Inositol Indol-3-Ylacetyltransferase (Indoleacetic Acid-Inositol Synthase)

A procedure is described for the purification of the enzyme indol-3-ylacetylglucose:myo-inositol indol-3-ylacetyltransferase (IAA-myo-inositol synthase). This enzyme catalyzes the transfer of indol-3-ylacetate from 1-0-indol-3-ylacetyl-β-d-glucose to myo-inositol to form indol-3-ylacetyl-myo-inositol and glucose. A hexokinase or glucose oxidase based assay system is described. The enzyme has been purified approximately 16,000-fold, has an isoelectric point of pH 6.1 and yields three catalytically inactive bands upon acrylamide gel electrophoresis of the native protein. The enzyme shows maximum transferase activity with myo-inositol but shows some transferase activity with scyllo-inositol and myo-inosose-2. No transfer of IAA occurs with myo-inositol-d-galactopyranose, cyclohexanol, mannitol, or glycerol as acyl acceptor. The affinity of the enzyme for 1-0-indol-3-ylacetyl-β-d-glucose is, K_m = 30 micromolar, and for myo-inositol is, K_m = 4 millimolar. The enzyme does not catalyze the exchange incorporation of glucose into IAA-glucose indicating the reaction mechanism involves binding of IAA glucose to the enzyme with subsequent hydrolytic cleavage of the acyl moiety by the hydroxyl of myo-inositol to form IAA myo-inositol ester.     

Fluorescence study ofEscherichia coli cyclic AMP receptor protein

Time-resolved, steady-state fluorescence and fluorescence-detected circular dichroism (FDCD) have been used to resolve the fluorescence contributions of the two tryptophan residues, Trp-13 and Trp-85, in the cyclic AMP receptor protein (CRP). The iodide and acrylamide quenching data show that in CRP one tryptophan residue, Trp-85, is buried within the protein matrix and the other, Trp-13, is moderately exposed on the surface of the protein. Fluorescence-quenching-resolved spectra show that Trp-13 has emission at about 350 nm and contributes 76–83% to the total fluorescence emission. The Trp-85, unquenchable by iodide and acrylamide, has the fluorescence emission at about 337 nm. The time-resolved fluorescence measurements show that Trp-13 has a longer fluorescence decay time. The Trp-85 exhibits a shorter fluorescence decay time. In the CRP-cAMP complex the Trp-85, previously buried in the apoprotein becomes totally exposed to the iodide and acrylamide quenchers. The FDCD spectra indicate that in the CRP-cAMP complex Trp-85 remains in the same environment as in the protein alone. It has been proposed that the binding of cAMP to CRP is accompanied by a hinge reorientation of two protein domains. This allows for penetration of the quencher molecules into the Trp-85 residue previously buried in the protein matrix.