Xenopsylla spp. (Siphonaptera: Pulicidae) in murid rodents from the Canary Islands: An update

The geographical and host distributions of Xenopsylla fleas parasitizing murid rodents on the Canary Islands have been reported. Three Xenopsylla species, X. cheopis, X. brasiliensis and X. guancha, have been detected on two rodents species, Mus musculus and Rattus rattus. X. guancha has been the most prevalent species detected, specifically on M. musculus, the most abundant rodent, but it has been detected only on three eastern islands, where the species is endemic. X. cheopis has been shown to be the most widely distributed species throughout the archipelago and the species most frequently found on R. rattus. X. brasiliensis has been shown to be the least prevalent Xenopsylla species, with the lowest geographical distribution on the Canary Islands and focused only on R. rattus. The detection of both X. cheopis and X. brasiliensis on the island of Lanzarote, and of X. guancha on the island of Fuerteventura and the islet of La Graciosa represents the first report of these species on those particular Canary Islands.     

Mycosporine glutamine and related mycosporines in the fungus Pyronema omphalodes

The structure of mycosporine glutamine, a new compound, has been established and its presence demonstrated in two fungi Pyronema omphalodes and Glomerella cingulata. Mycosporine glutamic acid has been isolated from Helvella leucomelaneae. Co-occurrence of normycosporine glutamine, mycosporine glutamine and glucosylmycosporine glutaminol has been demonstrated in the fungus P. omphalodes. A biosynthetic pathway is proposed. Mycosporines have been compared by HPLC.     

Bioinformatic analysis of maize granule-bound starch synthase gene

Alignment of the Wx-gene and its homolog sequences has been conducted. A dendrogram displaying phylogenetic relationship between Poaceae family members has been built. Transfer of ancient Wx-gene from Zea mays to Dimeria lawsonii has been assumed. Primers for the exons 8–10 of polymorphic region have been designed. In silico PCR analysis has been conducted.     

Transmission of sex cells of one species through the body of a second species in the genus Xenopus. II. Interspecific matings

Hybrids between X. mulleri and X. laevis have been prepared by two methods. By one method the hybridization has been effected either by a natural coupling following hormonal stimulation or by means of an artificial fertilization. By the other method, the primordial germ cells of mulleri have been introduced into laevis at the neurula stage and, when the host laevis had reached sexual maturity, the mulleri gametes produced have been brought into contact with laevis gametes through a natural coupling.     

9-hydroxyrhynchophylline-type oxindole alkaloids

Speciofoline has been assigned the epiallo B configuration on the basis of isomerization studies, NMR and CD spectra, and three new speciofoline isomers, mitrafoline (allo A), isomitrafoline (allo B) and isospeciofoline (epiallo A) have been isolated from Mitragyna speciosa Korth. Two new C-20 vinyl alkaloids, rotundifoleine and isorotundifoleine, have been separated as minor products from crystalline samples of rotundifoline and isorotundifoline respectively, previously isolated from M. parvifolia (Roxb.) Korth. A transient product observed during the isomerization of isorotundifoline has been identified as the pseudo B isomer, 3-epi-isorotundifoline.     

Phenolic compounds of the subfamily pomoideae: A chemotaxonomic survey

The subfamily Pomoideae has been surveyed for leaf phenolics and it has been shown that flavone glycosides are present in the genera Sorbus, Aronia, Chaenomeles and Hesperomeles in addition to the previously reported occurrences in Crataegus, Malus and Pyrus. The dihydrochalcone phloridzin, a typical constituent of Malus, has also been found in Docynia. Arbutin and phenolic acid-calleryanin esters are apparently restricted to Pyrus. Naringenin and eriodictyol glucosides have been detected in Pyracantha, Sorbus, Photinia, Chaenomeles and Hesperomeles. A number of Pomoideae phenolics have been found in two Spiraeoideae genera; luteolin 7-glucoside,] luteolin 7-diglucoside, luteolin 7-rhamnosylglucoside and apigenin 7-glucoside in Exochorda and the dihydrochalcone trilobatin in Sorbaria. The chemotaxonomic evidence is consistent with the hypothesis that the Pomoideae evolved through a process of allopolyploidy from primitive members of the Spiracoideae and Prunoideae.     

Centric diatom algae of volcanic Verkhneavachinsk lakes (Kamchatka)

Eleven representatives of diatom algae of the class Centrophyceae from the genera Aulacoseira (1), Conticribra (1), Cyclotella (5), Discostella (1), Stephanodiscus (2), and Thallasiosira (1) have been found in the phytoplankton of 5 volcanic lakes (Bakening volcano, Kamchatka). Stephanodiscus popovskayae, a species new for science, has been discovered in all the lakes, and a species new for the flora of Russia, Cyclotella gordonensis, has been found only in three lakes. The closest similarity in the composition of centric diatoms has been revealed between the lakes of a single water system: Lake Medvezh’e and Lake Verkhneavachinskoe.     

Pseudomonas aeruginosa and Achromobacter sp.: nitrifying aerobic denitrifiers have a plasmid encoding for denitrifying functional genes

In the present work, novel heterotrophic nitrifying and aerobic denitrifying bacteria have been isolated from greenwater system of coastal aquaculture. Based on the 16S rRNA gene, FAME analysis and biochemical test, the isolates have been identified as Pseudomonas aeruginosa and Achromobacter sp. These have been named as P. aeruginosa strain DBT1BNH3 and Achromobacter sp. strain DBTN3. Denitrifying functional genes such as nitrite reductase (nirS), nitric oxide reductase (qnorB) and nitrous oxide reductase (nosZ) genes have been identified. These strains found to have a 27 kb plasmid coding for nirS and nosZ. The possibility of horizontal transfer of plasmid among Pseudomonadaceae and Alcaligenaceae families in coastal aquaculture has been explored. Further, we have studied combined nitrification and oxygen tolerant denitrification potential in the same isolates.     

Les flavonoides de deux especes du genre Chrysosplenium

Five flavonols have been isolated from two species of Chrysosplenium; C. alternifolium contains penduletin 3,7-di-O-methylquercetagetin, 3,6,7-tri-O-methylquercetagetin and 3,3′,6,7-tetra-O-methylquercetagetin; C. oppositifolium possesses the last two compounds and 3,3′,7 tri-O-methylquercetagetin. These flavonols have been identified by chromatographic and spectral data; the taxonomic implication of this flavonoid pattern has been considered.     

Molecular biotechnology of marine algae in China

Molecular biotechnology of marine algae is referred to as the biotechnology on the identification, modification, production and utilization of marine algal molecules. It involves not only the manipulation of macromolecules such as DNA, RNA and proteins, but also deals with low molecular weight compounds such as secondary metabolites. In the last decade, molecular systematic researches to investigate the relationship and to examine the evolutionary divergence among Chinese marine algae have been carried out by Chinese scientists. For example, RAPD has been widely used in several laboratories to elucidate genetic variations of the reds, such as Porphyra, Gracilaria, Grateloupia and the greens such as Ulva and Enteromorpha. Some important data have been obtained. The study on molecular genetic markers for strain improvement is now in progress. In 1990s, genetic engineering of economic seaweeds such as Laminaria, Undaria, Porphyra, Gracilaria and Grateloupia has been studied in China. For Laminaria japonica, the successfully cultivated kelp in China, a model transformation system has been set up based on the application of plant genetic techniques and knowledge of the algal life history. Progress has been made recently in incorporating a vaccine gene into kelp genome. Evidence has been provided showing the expression of gene products as detectable vaccines. In the present paper, the progress of molecular biotechnological studies of marine algae in China, especially researches on elucidating and manipulating nucleic acids of marine algae, are reviewed.     

Diterpenoids from sideritis pusilla subsp. flavovirens

Several new 14-hydroxybeyerene acetates have been isolated from the aerial parts of Sideritis pusilla subsp. flavovirens. In addition, an ent-kaur-15-ene (siderol) and a new ent-7α, 18-dihydroxybeyer-15-ene (flavovirol) have been obtained from the same source. The structures of these new acetates have been established by chemical and spectroscopic means and the structure of flavovirol has been confirmed by ¹³C NMR.     

Identification of the subgenus Martes str. species (Martes zibellina, M. martes, M. foina, and M. melampus; Carnivora, Mustelidae) according to the mandibular metric characteristics

A comparative analysis involving 21 mandibular metric characteristics of Martes zibellina (n = 114), M. martes (117), M. foina (110), and M. melampus (6) has been performed using a graphical method (scatter diagrams) and stepwise discriminant analysis. The best metric characteristics allowing for discrimination between the lower jaws of these species have been identified and used to plot scatter diagrams. The discriminant analysis has been conducted for three groups of characteristics, namely, those of the whole mandible, ramus ascendens, and corpus mandibulae. As a result, optimal statistical models based on the diagnostic characteristics have been constructed and tested. The corresponding classification functions for species identification of whole mandibles and their fragments have been calculated. These results can be used for species identification of the mandibles of M. zibellina, M. martes, M. foina, and M. melampus.     

Increased Drought Tolerance through the Suppression of ESKMO1 Gene and Overexpression of CBF-Related Genes in Arabidopsis

Improved drought tolerance is always a highly desired trait for agricultural plants. Significantly increased drought tolerance in Arabidopsis thaliana (Columbia-0) has been achieved in our work through the suppression of ESKMO1 (ESK1) gene expression with small-interfering RNA (siRNA) and overexpression of CBF genes with constitutive gene expression. ESK1 has been identified as a gene linked to normal development of the plant vascular system, which is assumed directly related to plant drought response. By using siRNA that specifically targets ESK1, the gene expression has been reduced and drought tolerance of the plant has been enhanced dramatically in the work. However, the plant response to external abscisic acid application has not been changed. ICE1, CBF1, and CBF3 are genes involved in a well-characterized plant stress response pathway, overexpression of them in the plant has demonstrated capable to increase drought tolerance. By overexpression of these genes combining together with suppression of ESK1 gene, the significant increase of plant drought tolerance has been achieved in comparison to single gene manipulation, although the effect is not in an additive way. Accompanying the increase of drought tolerance via suppression of ESK1 gene expression, the negative effect has been observed in seeds yield of transgenic plants in normal watering conditions comparing with wide type plant.     

Antiviral potential of Bulgarian medicinal plants

Medicinal plants have been widely used to treat a variety of infectious and non-infectious diseases. Bulgarian flora includes 4,300 plant species, over 500 of which are rare or endemic to the country or the Balkan region. The aim of the present work is to summarize comprehensively the investigations on the antiviral activity of Bulgarian medicinal plants from the past three decades. The effect of different extracts derived from in vitro propagated plants has been examined as well. The phytochemical composition and its influence on specific steps of the viral life cycle have been discussed in this paper. The review includes the following families: Amaryllidaceae, Fabaceae, Geraniaceae, Lamiaceae, Onagraceae, Ranunculaceae, Rosaceae, Scrophulariaceae and Rhodophyta. Special attention has been paid to viruses as important human pathogens.     

Investigation of toxic Alternaria metabolites potentially present in UK-produced foods

Literature on the occurrence and toxicology of Alternaria mycotoxins shows that a wide range of Alternaria metabolites have been described although relatively few have been fully characterised. It has been reported that about half of the wild-type Alternaria cultures tested are highly toxic to mammals or birds but the compounds responsible have rarely been identified. Very little information is available on the nature or incidence of Alternaria mycotoxins in commodities grown in the UK. Preliminary results of an investigation of UK foods demonstrate the presence of several cytotoxic compounds in an ethyl acetate extract from an A. alternata culture. A toxic fraction has been isolated which appears to contain a compound not previously identified as an Alternaria mycotoxin.     

Human nucleotide sequences related to the transforming gene of a murine sarcoma virus: studies with cloned viral and cellular DNAs

A recombinant plasmid, pI26, has been constructed by cloning into pBR322 a transforming gene of murine sarcoma virus (a Moloney strain, clone 124, MSV) synthesized by detergent-treated virions. From this plasmid a XbaI-HindIII fragment has been isolated which contains only mos-specific sequences. This mos-specific probe has been used for screening a human gene library cloned in bacteriophage λ Charon 4A. Of these, 19 clones have been isolated containing mos-related sequences. By physical mapping and molecular hybridization it has been shown that these sequences are neighboured by DNA regions related to Moloney murine leukemia virus. Recombinant phages have also been found containing human inserts related to MLV, not to the mos gene. The possible existence of murine-like endogenous retroviruses in the normal human genome, including that of a sarcoma type, is discussed. By Northern blotting, expression of the cellular c-mos gene has been detected in mouse liver treated with a hepatocarcinogen. The general significance of the suggested model for evaluating the relationship between chemical carcinogenesis and oncogene expression is discussed.     

A CIS-Dominant Mutation in ASPERGILLUS NIDULANS Affecting the Expression of the amdS Gene in the Presence of Mutations in the Unlinked Gene, amdA

A mutant producing very high levels of the acetamidase enzyme encoded by the amdS gene has been isolated in a strain containing the amdA7 mutation, which itself causes high levels of this enzyme. Genetic analysis has shown that this mutation, designated amdI66, is adjacent to the amdS gene and is cis-dominant in its effect. The amdI66 mutation has little effect on amdS expression when present in strains not containing the amdA7 mutation. Two other amdA mutations investigated also interact with the amdI66 mutation to result in high acetamidase levels. No interaction between amdI66 and any of the other putative regulatory genes affecting amdS expression has been observed. The amdI66 mutation has been located by fine structure mapping at the extreme end of the controlling region, which has previously been defined by genetic mapping (Hynes 1979). Analysis of this region has been extended by mapping new mutations resulting in loss of amdS expression. One of these defines the most extreme site capable of mutation to loss of gene function found so far.