Characterization of Avian Paramyxoviruses Isolated from Feral Ducks in Northern Japan: The Presence of Three Distinct Viruses in Nature

Seventy-eight strains of avian paramyxoviruses (PMV) were isolated from cloacal and/or tracheal swabs taken from 1,342 feral ducks, comprised of spot-bill ducks, mallards, pintails, teals, falcated teals, wigeons and buffie-heads, in Wakuya-cho, Miyagi Prefecture, Japan, between 1976 and 1979. Five and a half percent of the ducks were positive for virus. Serological and structural characterization indicated that three different avian paramyxoviruses arc prevalent in the Japanese feral duck population. The first group of PMV was Newcastle disease virus (NDV), and in vivo pathogenecity tests in embryonated chicken eggs and 1-day-old chicks revealed that all the NDV strains isolated were avirulent. The second and most prevalent strain was closely related to PMV-4, duck/Hong Kong/D3/75 strain. The viruses of the third group were recovered only from pintails. They cross-reacted antigenically with PMV-3 when antisera to the PMV-3 reference strains, turkey/Wisconsin/68 and parakeet/Netherlands/449/75, were employed. However, no cross-reaction was observed when antiserum to pintail/ Wakuya/20/78, the prototype of this group, was used. The viruses of the third group also differed in viral polypeptide profile from the reference strains of PMV-3.     

The role of thromboxane A2 [TxA2] in liver injury in mice

The role of thromboxane A2 (TxA2) in CCl4-induced liver disease was investigated in mice. Significant elevation of TxB2 in the liver was observed 6 hours after the injection of CCl4. Administration of OKY-046, a selective TxA2 synthetase inhibitor (10 and 50 mg/kg) and ONO-3708, a TxA2 receptor antagonist, (0.5, 1 and 2 mg/Kg) suppressed the elevation of serum GOT and GPT levels and histopathological changes of the liver. In addition, OKY-046 inhibited the elevation of TxB2 in the liver. When U-46619, a stable TxA2 mimetic was injected i.v. into the mice, clear elevation of serum GOT and GPT levels and histopathological score of the liver were observed. These results suggest that TxA2 play a role for the onset of CCl4-induced liver injury in mice.     

In vitro study of transgenic tobacco expressing Arabidopsis wild type and mutant acetohydroxyacid synthase genes

Summary Genes coding for the enzyme acetohydroxyacid synthase, often referred to as acetolactate synthase (AHAS, ALS; EC 4.1.3.18), from wild type Arabidopsis thaliana and a sulfonylurea-resistant mutant line GH50 (csrl-1; Haughn et al. 1988) were introduced in Nicotiana tabacum. Both genes were expressed at high levels with the 35S promoter. The csrl-1 gene conferred high levels of resistance to chlorsulfuron whereas the wild type gene did not. As selectable markers, chimaeric AHAS genes yielded transgenic plants on chlorsulfuron but at much lower efficiencies than with a chimaeric neomycin phosphotransferase gene on kanamycin (Sanders et al. 1987). Shoot differentiation from leaf discs was delayed on chlorsulfuron by 4–6 weeks. This study indicated a role for mutant AHAS genes in the genetic manipulation of herbicide resistance in transgenic plants but as selectable markers for plant cells undergoing differentiation no advantage over other genes was perceived.     

Immunohistochemical localization of Na+-dependent glucose transporter in rat jejunum

Summary Glucose is actively absorbed via a Na⁺-dependent active glucose transporter (Na-GT) in the small intestine. We raised a polyclonal antibody against the peptide corresponding to amino acids 564–575 of rabbit intestinal Na-GT, and localized it immunohistochemically in the rat jejunum. By means of immunofluorescence staining, Na-GT was located at the brush border of the absorptive epithelial cells of the intestinal villi. Electron-microscopic examination showed that Na-GT was localized at the plasma membrane of the apical microvilli of these cells. Little Na-GT was found at the basolateral plasma membrane. Along the crypt-villus axis, all of the absorptive epithelial cells in the villus were positive for Na-GT. In addition to the brush border staining, the supranuclear positive staining, which was shown to be the Golgi apparatus by use of electron microscopy, was seen in cells located between the base to the middle of the villus. Cells in crypts exhibited little or no staining for Na-GT. Goblet cells scattered in the intestinal epithelium were negative for Na-GT staining. These observations show that Na-GT is specific to the apical plasma membrane of the absorptive epithelial cells, and that the onset of Na-GT synthesis may occur near the crypt-villus junction.     

Molecular characterization and genetic origin of the Brassica napus acetohydroxyacid synthase multigene family

Summary The Brassica napus rapeseed cultivar Topas contains an acetohydroxyacid synthase (AHAS) multigene family consisting of five members (AHAS 1–5). DNA sequence analysis indicate that AHAS1 and AHAS3 share extensive homology. They probably encode the AHAS enzymes essential for plant growth and development. AHAS2 has diverged significantly from AHAS1 and AHAS3 and has unique features in the coding region of the mature polypeptide, transit peptide and upstream non-coding DNA, which raises the possibility that it has a distinct function. AHAS4 and AHAS5 have interrupted coding regions and may be defective. The complexity of the AHAS multigene family in the allotetraploid species B. napus is much greater than reported for Arabidopsis thaliana and Nicotiana tabacum. Analysis of the presumptive progenitor diploid species B. campestris and B. oleracea indicated that AHAS2, AHAS3 and AHAS4 originate from the A genome, whereas AHAS1 and AHAS5 originate from the C genome. Further variation within each of the AHAS genes in these species was found.     

Promotive Effect of C18-Unsaturated Fatty Acids on the Abscission of Bean Petiole Explants

The abscission-promoting effects of C₁₈-unsaturated fatty acidswere studied in bean (Phaseolus vulgaris L. cv. Masterpiece)petiole explants with the junction between the petiole and thepulvinus in the primary leaves in the light. Linolenic, linoleicand oleic acids promoted the abscission of the explants in thelight. Linolenic acid was the most effective among the compoundstested and its promotive effect was evident without any accompanyingincrease in the production of ethylene from the explants, ascompared with non-treated explants. Linolenic acid is easilyconverted to its hydroperoxide during the incubation with explants,as indicated by the formation of the conjugated diene and thegeneration of ethane. The production of ethylene from the explantstreated with linolenic acid was completely inhibited by theaddition of aminoethoxyvi-nylglycine (AVG), but large amountsof ethane were still generated. The promotive effect of linolenicacid was almost eliminated by the addition of scavengers offree radicals. Hydrogen peroxide and tert-butyl hydroperoxidepromoted abscission in the light. From these results, we concludedthat the abscission-promoting effect of linolenic acid are notmediated by the effect of ethylene but by the effect of itshydroperoxide, while the well-established pathway for the biosynthesisof ethylene from S-adenosylmethionine to ethylene, via 1-aminocyclopropane-l-carboxylicacid (ACC), was apparently operative. (Received May 1, 1991; Accepted July 10, 1991)     

Analysis of bacterial populations in a grassland soil according to rates of development on solid media

Abstract The process of colony formation by bacteria from grassland soil sampled in April, July and September was simulated by a colony-forming curve (CFC). The CFC was a super-imposition of several component curves (cCFC) given theoretically by the first order reaction (FOR) model [3,6]. The pattern of FOR model curves was not influenced by the time of sampling and four cCFCs were always recognized during an incubation period of 160 h. It was considered that the CFC describes an inherent property of the bacterial population of the field. Bacterial isolates were obtained from colonies produced in each of four cCFCs on agar plates. Isolates corresponding to one cCFC were classified as one group. The bacterial isolates were characterized by morphological and physiological tests and subsequently clustered. Few oligotrophic bacteria were obtained among bacteria which produced visible colonies within 63 h of incubation time. On the other hand, approx. 50% of bacteria which produced v colonies after 63 h were oligotrophic bacteria. The time required for the appearance of the first colony, t _r of the FOR model, was very similar in the isolates belonging to one group. A close linear relationship was observed between t _r value and doubling time of isolates.     

Distinction of three types of D-glucose transport systems in animal cells

Immunoblotting of plasma membrane fractions from rat kidney cortex with antibody to human erythrocyte glucose transporter showed a single major cross-reacting material of 48K in basolateral membrane fractions possessing a facilitated diffusion system for D-glucose, but not in brush border membrane fractions which have a Na-dependent active transport system. Cytochalasin B inhibited D-glucose uptake in basolateral membrane vesicles but not in brush border vesicles. Cross-reacting materials of 44-55K were detected in several animal cells exhibiting facilitated diffusion systems, including a hormone dependent system. These results indicate molecular difference between glucose transporters of facilitated diffusion systems and active transport systems.     

Demonstration of structural polymorphism among MB3 light chains by two-dimensional gel electrophoresis

The heavy and light chain subunits of MB3 molecules were isolated from KT2 (DKT2, DR4, MB3 homozygous), ER (Dw4, DR4, MB3 homozygous), JMe (Dw5, DR5, MB3 homozygous), EBV-Sh (DSh, DRw6.2, MB3 homozygous), and EBV-Ky (DKy, DRw9, MB3 homozygous) cells and were compared with one another by two-dimensional gel electrophoresis. The MB3 light chains from KT2, ER, and EBV-Ky cells were clearly different in terms of their isoelectric points, whereas those from ER, JMe, and EBV-Sh cells were indistinguishable. No differences in charge or m.w. were noted for the MB3 heavy chains from the five cell lines. Thus, three out of the five MB3-positive, D/DR-disparate cell lines were found to express structurally distinct MB3 molecules, demonstrating that MB3 is a public serologic specificity shared by at least three structurally distinct MB (human I-A-like) molecules. Because the DR light chain subunits isolated from EBV-Wa, KT2, ER, JMe, EBV-Sh, and EBV-Ky cells differed from one another in their isoelectric points, the DR light chains were apparently more polymorphic than the MB3 light chains.     

Feeding ecology of mandrills (Mandrillus sphinx) in campo animal reserve,Cameroon

A field study on the ecology of mandrills (Mandrillus sphinx) was carried out for 28 months in Cameroon. Fresh food remnants and large quantities of fresh feces were collected by following the groups. Analyses of these products indicated that fruit (including seeds), monocotyledonous plant leaves and insects (especially ants and termites), were frequently eaten. Mandrills mostly ate the plant and animal foods in the lower forest stratum and on the ground. Fallen seeds and monocotyledonous plant leaves were eaten more frequently in the minor fruiting season than in the major fruiting season presumably to compensate for the shortage of fresh fruit during the former. Daily travel distances were shorter during the minor fruiting season than during the major fruiting season, because in the minor fruiting season mandrills forage for small food items, such as the new leaves and piths of monocotyledons and fallen seeds which are sparsely distributed on the ground, while in the major fruiting season they search for widely distributed food such as fruit. The daily pattern of group movement and a food intake experiment suggest that mandrills move and feed continuously throughout the day. Use of fallen seeds and monocotyledonous plant leaves appears to enable mandrills to maintain a terrestrial life in the tropical rain forest. The feeding and ranging characteristics of mandrills are basically similar to those of other baboon species in open land, though their environments differ extremely.