Cytochrome cs from Rhodymenia palmata and Porphyra umbilicalis and the amino acid sequences of their N-terminal regions

Basic c-type cytochromes homologous with plant and animal mitochondrial cytochrome c have been isolated and purified from Rhodymenia palmata and Porphyra umbilicalis. The N-terminal regions have been analysed using a Beckman 890C automatic sequencer. When compared to animal cytochrome c, the Rhodymenia cytochrome c has an unblocked N-terminal tail of 10 amino acids, whereas Porphyra has an unblocked N-terminal tail of only a single amino acid.     

Polyacetylenes of Dahlia

Two Dahlia sherffii strains and three Dahlia pinnata strains and Dahlia rudis Sorensen have been investigated for polyacetylenes. A great number of acetylenic compounds, characterized earlier from other Dahlia species was determined. The two Dahlia sherffii strains and the three Dahlia pinnata strains contain 1-phenylhept-5-ene-1,3-diyne and 1-phenyl-hepta-1,3,5-triyne and derivatives which have previously been found in one Dahlia coccinea strain and in a horticultural form. A comparison between this group of dahlias with others previously investigated, show characteristic differences in the chemical pattern. Dahlia rudis is thus closer to the D. imperialis and the D. tenuicaulis and three of the Dahlia coccinea strains. Dahlia merckii exhibits a quite unique pattern of polyacetylenes.     

Bestrophin genes are expressed in Xenopus development

The Bestrophin-1/VMD2 gene has been implicated in Best disease, a juvenile-onset vitelliform macular dystrophy. The Bestrophin proteins have anion channel activity, and the four mammalian members share sequence homologies in multiple transmembrane domains and an RFP-tripeptide motif. The expression patterns and functions of the Bestrophin genes in retinal pigment epithelium have been studied intensively, whereas little is known about their roles in vertebrate embryogenesis. This study examined the roles of four Xenopus tropicalis homologs of BEST genes. The xtBest genes showed spatially and temporally distinct expression. xtBest-2 was the only maternally expressed Best gene, and both xtBest-2 and the Xenopus laevis Best-2 gene were expressed at the edge of the blastopore lip including the organizer. Ectopic expression of xBest-2 caused defects in dorsal axis formation and in mesodermal gene expression during gastrulation. These results suggest a new role of the Bestrophin family genes in early vertebrate embryogenesis.     

Polyacetylenes from Chrysanthemum leucanthemum

Fifteen acetylenic compounds have been isolated and characterized from the flower heads of Chrysanthemum leucanthemum L. Five of these acetylenes have not previously been published as naturally occurring compounds. These are: 1,7(c)-hexadecadien-10,12,14-triyne; 1,8(c)-heptadecadien-11,13,15-triyne; 4(c)-tridecen-7,9,11-triyn-l-ol; 1,8(t)-hexadecadien-10,12,14-triyn-(6·7)-oxirane; and [3(t),5(t)-tridecadien-7,9,11-triyn-l-yl]-3-methyl-2-butenoate. The first three compounds are interesting since they are important intermediates in previously postulated biogenetic pathways. Ten acetylenes have been identified from the roots of the same plant, all of these having different structures from those of the flower heads. One of the acetylenes, [3(t), 5(t)-tridecadien-7,9,11-triyn-l-yl]-3-methylbutyrate, from the roots has never been reported as a naturally occurring compound.     

Pyrrolizidine alkaloids from Senecio cacaliaster

Four pyrrolizidine alkaloids have been isolated from Senecio cacaliaster and their structures analysed by spectroscopic methods (IR, mass, ¹H, ¹³CNMR). One of them is new and the name sencalenine (3) is proposed. Alkaloids O⁷-senecioylretronecine (1) and 7-senecioyl-9-sarracinylretronecine (2) have recently been identified elsewhere. The fourth is bulgarsenine (4) which was isolated from a Senecio species before.     

Hydroxylated glutamic acids in Phlox,lepidium and Rheum species

The two diastereoisomers, (2S,4R)-4-hydroxyglutamic acid and (2S,4S)-4-hydroxyglutamic acid, occur in characteristic concentration ratios in Phlox species. The second of these compounds is the principal free amino acid in the green parts of the plants. The presence of (2S,4R)-4-hydroxyglutamic acid in plants is reported for the first tiine. No other 4-substituted acidic amino acids were detected in the Phlox species analysed, although special attention was paid to the possible presence of 4-hydroxy-4-methylglutamic acids which have previously been reported in plants. It was found, however, that both diastereoisomers of (2S)-4-hydroxy-4-methylglutamic acid co-exist in Ledenbergia roseoaenea and also in Pandanus veitchii. Although the presence of 3,4-dihydroxyglutamic acids in green parts of Lepidium sativum and Rheum rhaponticum has been previously reported, we were not able to detect or isolate any of the possible diastereoisomers from the green parts or seeds of these plants. We did isolate glutathione which was found to have some properties in common with those reported for the dihydroxy compounds.     

Phenolic acids in the genus Lycopodium

The dihydric phenolics from the leaves of 170 Ecuadorian Lycopodium specimens representing 49 species and varieties have been examined as semiquinones by EPR spectroscopy. An ester of dihydrocaffeic acid was observed in 137 extractors of specimens all confined to the subgenus Urostachya. The ester was not present in the subgenera Lycopodium and Lycopodiella, where the dominant phenolic acid was chlorogenic acid. The concentrations of the “Urostachyaester” were found to increase with increasing altitude. Hydroquinone and protochatechuic acid have been observed in a few specimens.     

Fluorescence in situ hybridization for intracellular localization of nifH mRNA

Few reports on in situ mRNA detection in bacteria have been published, even though a major aim in environmental microbiology is to link function/activity to the identity of the organisms. This study reports a reliable approach for the in situ detection of nifH mRNA using fluorescence hybridization based on a previously described protocol for pmoA. nifH codes for a dinitrogenase reductase, a key enzyme in dinitrogen fixation. nifH mRNA was hybridized with a digoxigenin-labelled polynucleotide probe. The hybrid was detected with an anti-DIG-antibody labelled with horseradish peroxidase. Subsequently, the signal was amplified by catalyzed reporter deposition (CARD) with fluorochrome-labelled tyramides. Furthermore, the imaged organisms were identified using standard fluorescence in situ hybridization of rRNA. Thus, the approach enabled us specifically to link in situ the information from the dinitrogen fixation activity of an organism to its identity. Unexpectedly, the signals derived from nifH mRNA hybridization showed a distinct uneven pattern within the cells. This indicated that the method used could even give insights about the localization of the detected mRNA within the cell, which is a potential use of mRNA fluorescence in situ hybridization (FISH) that has not been reported up to now for bacterial cells.     

(3R,3′R)-astaxanthin from the yeast Phaffia rhodozyma

Astaxanthin isolated from the yeast Phaffia rhodozyma has the 3R,3′R-configuration, opposite to that of astaxanthin from other sources which have been so far investigated. This is the first example of a naturally occurring carotenoid biosynthesized in different optical forms. A possible explanation is advanced.     

Molecular and histological identification of Marteilioides infection in Suminoe Oyster Crassostrea ariakensis, Manila Clam Ruditapes philippinarum and Pacific Oyster Crassostrea gigas on the south coast of Korea

The oyster ovarian parasite Marteilioides chungmuensis has been reported from Korea and Japan, damaging the oyster industries. Recently, Marteilioides-like organisms have been identified in other commercially important marine bivalves. In this study, we surveyed Marteilioides infection in the Manila clam Ruditapes philippinarum, Suminoe oyster Crassostrea ariakensis, and Pacific oyster Crassostrea gigas, using histology and Marteilioides-specific small subunit (SSU) rDNA PCR. The SSU rDNA sequence of M. chungmuensis (1716 bp) isolated from C. gigas in Tongyoung bay was 99.9% similar to that of M. chungmuensis reported in Japan. Inclusions of multi-nucleated bodies in the oocytes, typical of Marteilioides infection, were identified for the first time in Suminoe oysters. The SSU rDNA sequence of a Marteilioides-like organism isolated from Suminoe oysters was 99.9% similar to that of M. chungmuensis. Marteilioides sp. was also observed from 7 Manila clams of 1840 individuals examined, and the DNA sequences of which were 98.2% similar to the known sequence of M. chungmuensis. Unlike Marteilioides infection of Pacific oysters, no remarkable pathological symptoms, such as large multiple lumps on the mantle, were observed in infected Suminoe oysters or Manila clams. Distribution of the infected Manila clams, Suminoe oysters and Pacific oysters was limited to small bays on the south coast, suggesting that the southern coast is the enzootic area of Marteilioides infection.     

Diterpenes from Marrubium sericeum, Marrubium supinum and Marrubium alysson

From some Marrubium species endemic in the Iberian Peninsula, four new diterpenoids, 6-acetyl-marrubenol, 19-acetyl-marrubenol, premarrubenol and 6-acetyl-premarrubenol, have been isolated. The previously known diterpenes marrubiin and marrubenol have also been obtained from the same sources.     

Phyllocarida and the origin of the Malacostraca

Tentative homologies with Decapoda are proposed for grooves on the carapace of Echinocaris and Montecaris. Together with F.R. Schram's hoploid trend, reinforced by the discovery of a raptorial limb in Sairocaris, this may strengthen a phyllocarid origin for Eumalacostraca. Both these trends, however, may be parallelisms, and phylogenetic analysis is required. Pleopods are here proved to have been present in additional Archaeostraca, which improves their ancestral condition. E. Dahl's view of the phyllocarids as an evolutionary dead end is falsified from fossils, and the phyllocarids are supported as a stem group of the Malacostraca.     

Structure and development of the style base in Abildgaardia, Bulbostylis, and Fimbristylis (Cyperaceae,Cyperoideae, Abildgaardieae)

The Abildgaardieae tribe within the family Cyperaceae comprises six or seven genera, among which Abildgaardia, Bulbostylis and Fimbristylis pose a challenge regarding their morphological delimitation. Molecular phylogenetic analyses including species of Abildgaardieae are rare, but in most of those studies, Abildgaardia and Fimbristylis appear as more closely related to each other than to the Bulbostylis genus. Duration of the style base has been one of the most widely used characters for delimiting these three genera. The style base is a persistent structure in most species of Bulbostylis and deciduous in Abildgaardia and Fimbristylis. The reasons why the style base may persist or fall off have been scarcely discussed. The assumption that abscission layers are present in the style base of all three genera and the fact that tracheids have been observed in the style base of Bulbostylis suggest that this structure might have histological complexity. In view of this, a complete ontogenetic and anatomical study of the gynoecium has been carried out for all these three genera. It turned out that the style base is histologically simple in Abildgaardia, Bulbostylis and Fimbristylis and shows similar structure and development in all three genera. The fact that the style base has a shorter duration in Abildgaardia and Fimbristylis than in Bulbostylis might be related to the lower number of sclerotised cells that make up such structures in the mature fruit of the former two genera. Abscission of the style and style base may be the result of much simpler reasons than the differentiation of an abscission layer, resulting merely from mechanical shear force effects. Differences among genera have been observed in the shape of the style base and the development of the style. The histological simplicity of the style base is consistent with the homoplastic appearance of this structure in genera that are not closely related (e.g. Rhynchospora). Because of this, while the presence of the thickened style base seems to be a synapomorphy in species of Abildgaardieae, its persistence on or detachment from the fruit might have emerged repeatedly during this clade evolution and might not be a suitable character for genera delimitation.     

Outgrowth of nerve fibres from Drosophila central nervous system cultured in vitro

Explants of the central nervous system of Drosophila have been shown to produce nerve fibres in vitro. The effects of various culture conditions on fibre outgrowth have been examined. Nervous tissue could form nerve fibres in vitro when the explants were obtained from mid-embryonic or early- and mid-pupal stages, but not when they were obtained from larvae or late-pupae. The effect of the temperature-sensitive mutation shibire^ts has been investigated by placing mutant explants into culture at permissive (17°C) or restrictive (28°C) temperatures. No differences in the extent of fibre outgrowth between wild-type and shibire^ts were observed, regardless of the temperature of cultivation.     

Evolutionary divergence of the paralogs Methoprene tolerant (Met) and germ cell expressed (gce) within the genus Drosophila

Juvenile hormone (JH) signaling underpins both regulatory and developmental pathways in insects. However, the JH receptor is poorly understood. Methoprene tolerant (Met) and germ cell expressed (gce) have been implicated in JH signaling in Drosophila. We investigated the evolution of Met and gce across 12 Drosophila species and found that these paralogs are conserved across at least 63 million years of dipteran evolution. Distinct patterns of selection found using estimates of dN/dS ratios across Drosophila Met and gce coding sequences, along with their incongruent temporal expression profiles in embryonic Drosophila melanogaster, illustrate avenues through which these genes have diverged within the Diptera. Additionally, we demonstrate that the annotated gene CG15032 is the 5′ terminus of gce.In mosquitoes and beetles, a single Met-like homolog displays structural similarity to both Met and gce, and the intron locations are conserved with those of gce. We found that Tribolium and mosquito Met orthologs are assembled from Met- and gce-specific domains in a modular fashion. Our results suggest that Drosophila Met and gce experienced divergent evolutionary pressures following the duplication of an ancestral gce-like gene found in less derived holometabolous insects.     

Etude chimiotaxonomique dans les genres Macrotyloma, Dolichos et Pseudovigna

The variations of free, protein and total amino acid contents have been studied in seeds of Macrotyloma, Dolichos and Pseudovigna. The concentrations of free amino acids and of γ-glutamylphenylalanine seem to be characteristic of some species and also of some genera.     

Proteases from the fungus Metarhizium anisopliae toxic for Galleria mellonella larvae

The high molecular fraction of the extract from Metarhizium anisopliae grown on wheat bran contains proteolytic enzymes which are toxic for Galleria mellonella larvae. The complex of proteases was fractionated using precipitation with ammonium sulfate, gel filtration, and electrofocusing. Two components have been found: one with the optimum of activity on hemoglobin at pH 6.5, and the second with the optimum around pH 9. The prevailing protease acting at pH 6.5 was inhibited by phenylmethylsulfonyl fluoride and the inhibition was followed by decrease of toxicity. The molecular weights of the enzymes are 35 × 10³ and 71 × 10³.     

Tropane alkaloids from Anthocercis and Anthotroche

In addition to known tropane alkaloids, 3α-iso-butyryloxytropan-6β-ol and 3α-n-butyryloxytropane have been characterized as respective components of the aerial parts of two subspecies of Anthocercis albicans. Aponoratropine, not previously recorded as a natural product, has been detected in the leaves of Anthotroche myoporoides and A. walcottii; similarly aponorhyoscine is indicated as a component of the roots of a subspecies of Anthocercis genistoides.     

Characterization of the mating-type genes in Leptographium procerum and Leptographium profanum

Leptographium procerum and the closely related species Leptographium profanum, are ascomycetes associated with root-infesting beetles on pines and hardwood trees, respectively. Both species occur in North America where they are apparently native. L. procerum has also been found in Europe, China New Zealand, and South Africa where it has most probably been introduced. As is true for many other Leptographium species, sexual states have never been observed in L. procerum or L. profanum. The objectives of this study were to clone and characterize the mating type loci of these fungi, and to develop markers to determine the mating types of individual isolates. To achieve this, a partial sequence of MAT1-2-1 was amplified using degenerate primers targeting the high mobility group (HMG) sequence. A complete MAT1-2 idiomorph of L. profanum was subsequently obtained by screening a genomic library using the HMG sequence as a probe. Long range PCR was used to amplify the complete MAT1-1 idiomorph of L. profanum and both the MAT1-1 and MAT1-2 idiomorphs of L. procerum. Characterization of the MAT idiomorphs suggests that the MAT genes are fully functional and that individuals of both these species are self-sterile in nature with a heterothallic mating system. Mating type markers were developed and tested on a population of L. procerum isolates from the USA, the assumed center of origin for this species. The results suggest that cryptic sexual reproduction is occurring or has recently taken place within this population.