Lectins as markers of rumen epithelial cell differentiation

Summary Lectins of different carbohydrate specificities (GNA (Galanthus nivalis), con A (Canavalia ensiformis), VFL (Vicia faba), PSL (Pisum sativum), LCA (Lens culinaris), PNA (Arachis hypogaea; with or without prior neuraminidase treatment), WGA (Triticum vulgare), SBA (Glycine max), UEA-I (Ulex europaeus), LPA (Limulus polyphemus), BS-I B₄ (Bandeiraea simplicifolia, isolectin B₄)) were explored for use as differentiation markers of rumen epithelial cellsin vivo andin vitro. Lectins specific for mannose (GNA), mannose/glucose (con A, VFL, PSL and LCA),N-acetylglucosamine (WGA) or forN-acetylneuraminic acid (LPA) reacted generally with all types of rumen epithelial cell from both rumen tissue and cell culture. They were, therefore, not suitable markers of epithelial differentiation. SBA was unsuitable because, although it reacted with both tissue and cultured rumen epithelial cells, it was also bound to non-stratified areas of primary rumen epithelial cell cultures. Both BS-I B₄ and PNA (after neuraminidase treatment) had to be ruled out because they did not react with differentiated rumen tissue epithelial cells, although they did bind to both stratified and non-stratified cultured cells. In contrast, UEA-I reacted strongly with differentiated rumen epithelial cells both from rumen tissue and cell cultures and therefore appears to be a good general marker for rumen epithelial cell differentiation.     

Paracuaria hispanica n. sp. (Nematoda: Acuariidae), a stomach parasite of the pyrenean desman Galemys pyrenaicus Geoffr. (Insectivora: Talpidae), with a redefinition of the genus Paracuaria Rao, 1951

Adult and fourth-stage larvae of Paracuaria hispanica n. sp., from the stomach of the Pyrenean desman Galemys pyrenaicus Geoffroy (Insectivora: Talpidae) in northern and central Spain, are described. The new species differs from the other members of the genus Paracuaria (P. adunca and P. soricis), among other morphological details, in its smaller body and spicule sizes, the presence of a cuticular ring around the tip of the female tail, and the existence of lateral alae running longitudinally along its body from the cervical region to the tail. In view of the latter feature, the genus Paracuaria is redefined. The fourth stage larva of the new species is distinguished from that of P. adunca by its monocuspid deirids. P. hispanica occurred in 45% of the 20 host specimens examined.     

Allagoptera brevicalyx (Palmae), a new species from Bahia,Brazil

Allagoptera brevicalyx from Bahia, Brazil, is described. It is compared to other species ofAllagoptera and also toPolyandrococos.     

The Glucose-Related Decrease in Polar Auxin Transport During Ripening and its Possible Role in Grapevine Berry Coloring

Journal of Plant Growth Regulation - Auxin is a hormone that delays ripening in part by reducing anthocyanin content and impairing color development. Auxin content declines during the ripening...     

Effects of vagal neuromodulation and vagotomy on control of food intake and body weight in rats.

Food induced neurohumoral signals are conduced to data processing brain centers mainly as vagal afferent discharge resulting in food intake regulation. The aim of this study was to evaluate effects of vagal nerve neuromodulation in control of food intake with fed-pattern microchip (MC) pacing. Experiments were performed on 60 rats divided on 5 groups: I group 0,05Hz left vagal pacing, II - pacing of both vagal nerves with MC 0,05Hz, III- left vagal MC 0,1Hz pacing, IV - pacing of both vagal nerves with MC 0,1 Hz was performed. In group V left vagal pacing was combined with right side abdominal vagotomy. Body weight and total food intake decreased by 12% and 14% (I), 26% and 30%(II), 8% and 21%(III), 14% and 30%(IV), 38% and 41%(IV), respectively (p<0.05). Effects of both vagal nerves stimulation on final body weight and food intake was significantly more effective than only single nerve MC pacing however most effective was stimulation with 0,1Hz combined with right vagotomy. We conclude that vagal stimulation reduce food intake and body weight by increasing vagal afferent signals. Our results suggest that information in vagal afferents can be modulated resulting in changes of feeding behaviour and body weight.     

Through-bond correlation of adenine H2 and H8 protons in unlabeled DNA fragments by HMBC spectroscopy

Summary A new application of the HMBC experiment is presented that provides a useful means to discriminate between H2 and H8 proton resonances, to assign the base proton resonances to the various residue types and, most importantly, to correlate the H2 and H8 protons for adenine or inosine residues in natural abundance ¹³C fragments. The utility of this experiment is demonstrated for an unlabeled DNA 20-mer. Thanks to the obtained results, preliminary conclusions could be drawn regarding the molecular conformations of the non-canonical G/I-A base pairs in the hairpin formed by this fragment.     

Maximum-likelihood models for mapping genetic markers showing segregation distortion. 2. F2 populations

In F₂ populations, gametic and zygotic selection may affect the analysis of linkage in different ways. Therefore, specific likelihood equations have to be developed for each case, including dominant and codominant markers. The asymptotic bias of the classical estimates are derived for each case, in order to compare them with the standard errors of the suggested estimates. We discuss the utility and the efficiency of a previous model developed for dominant markers. We show that dominant markers provide very poor information in the case of segregation distortion and, therefore, should be used with circumspection. On the other hand, the estimation of recombination fractions between codominant markers is less affected by selection than is that for dominant markers. We also discuss the analysis of linkage between dominant and codominant markers.     

Inhibition by trifluoperazine of ATP synthesis and hydrolysis by particulate and soluble mitochondrial F1: Competition with H2PO 4 −

The effect of trifluoperazine (TFP) on the ATPase activity of soluble and paniculate F₁ATPase and on ATP synthesis driven by succinate oxidation in submitochondrial particles from bovine heart was studied at pH 7.4 and 8.8. At the two pH. TFP inhibited ATP hydrolysis. Inorganic phosphate protected against the inhibiting action of TFP. The results on the effect of various concentrations of phosphate in the reversal of the action of TFP on hydrolysis at pH 7.4 and 8.8 showed that H₂PO ₄ ^– is the species that competes with TFP. The effect of TFP on oxidative phosphorylation was studied at concentrations that do not produce uncoupling or affect the aerobic oxidation of succinate (<15M). TFP inhibited oxidative phosphorylation to a higher extent at pH 8.8 than at pH 7.4; this was through a diminution in theV _max, and an increase in theK _m for phosphate. Data on phosphate uptake during oxidative phosphorylation at several pH showed that H₂PO ₄ ^– is the true substrate for oxidative phosphorylation. Thus, in both synthesis and hydrolysis of ATP, TFP and H₂PO ₄ ^– interact with a common site. However, there is a difference in the sensitivity to TFP of ATP synthesis and hydrolysis; this is more noticeable at pH 8.8, i.e. ATPase activity of soluble F₁ remains at about 40% of the activity of the control in a concentration range of TFP of 40–100M, whereas in oxidative phosphorylation 14M TFP produces a 60% inhibition of phosphate uptake.     

The IleL229 → Met mutation impairs the quinone binding to the QB-pocket in reaction centers of Rhodobacter sphaeroides

A spontaneous mutant (R/89) of photosynthetic purple bacterium Rhodobacter sphaeroides R-26 was selected for resistance to 200 M atrazin. It showed increased resistance to interquinone electron transfer inhibitors of o-phenanthroline (resistance factor, RF=20) in UQ_o reconstituted isolated reaction centers and terbutryne in reaction centers (RF=55) and in chromatophores (RF=85). The amino acid sequence of the Q_B binding protein of the photosynthetic reaction center (the L subunit) was determined by sequencing the corresponding pufL gene and a single mutation was found (Ile^L229 Met). The changed amino acid of the mutant strain is in van der Waals contact with the secondary quinone Q_B. The binding and redox properties of Q_B in the mutant were characterized by kinetic (charge recombination) and multiple turnover (cytochrome oxidation and semiquinone oscillation) assays of the reaction center. The free energy for stabilization of Q_AQ_B ^– with respect to Q_A ^–Q_B was G_AB=–60 meV and 0 meV in reaction centers and G_AB=–85 meV and –46 meV in chromatophores of R-26 and R/89 strains at pH 8, respectively. The dissociation constants of the quinone UQ_o and semiquinone UQ_o ^– in reaction centers from R-26 and R/89 showed significant and different pH dependence. The observed changes in binding and redox properties of quinones are interpreted in terms of differential effects (electrostatics and mesomerism) of mutation on the oxidized and reduced states of Q_B.Abbreviations BChl bacteriochlorophyll - Ile isoleucine - Met methionin - P primary donor - Q_A primary quinone acceptor - Q_B secondary quinone acceptor - RC reaction center protein - UQ_o 2,3-dimethoxy-5-methyl benzoquinone - UQ₁₀ ubiquinone 50 This work is dedicated to the memory of Randall Ross Stein (1954–1994) and is, in a small way, a testament to the impact which Randy's ideas have had on the development of the field of competitive herbicide binding.     

Polymorphism in the Ostertagiinae Lopez-Neyra, 1947 and comments on the systematics of these nematodes

A list of 19 polymorphic species of the generaOstertagia, Orloffia, Teladorsagia, Marshallagia andSpiculopteragia is presented. The morphs of the polymorphic species in question have identical females and show similarities in some male features, e.g. the structure of the oesophagus, the synlophe and the shape of the rays of the copulatory bursa. However, they differ by characters which are recognised as generic features, e.g. the structure of spicules, gulbernaculum and genital cone. The presence or lack of minor morphs is a generic feature in the Ostertagiinae. Each polymorphic genus has a defined type of minor morph.