Phylogenetic analysis of Antrodia and related taxa based on partial mitochondrial SSU rDNA sequences

Sequences of mitochondrial SSU rDNA were obtained from six species of Antrodia and related fungal taxa to reveal their phylogenetic relationships. Phylogenetic analysis showed that the species of Antrodia did not cluster into a single clade. Brown rot fungi were separated into two main groups through which Antrodia was dispersed. Antrodia sinuosa, A. serialis, A. heteromorpha and A. malicola clustered with Perenniporia, Fomitopsis, Piptoporus, Daedalea and Melanoporia within one group of brown rot fungi, while A. carbonica and A. vaillantii clustered with Oligoporus, Gloeophyllum and Auriporia within the other group of brown rot fungi, indicating that Antrodia is a heterogeneous genus and that brown rot fungi have evolved convergently.

Effect of electroacupuncture on response to immobilization stress

Forced immobilization is a simple and effective stressor which produces large increases in heart rate (HR), blood pressure (BP), and plasma levels of norepinephrine (NE) and epinephrine (EPI). This study investigated the effects of electroacupuncture on BP, HR, and plasma catecholamine levels in rats challenged with immobilization stress. Male Sprague-Dawley rats received electroacupuncture (3 Hz, 0.2 ms pulses, 20 mA) for 30 min after start of immobilization stress (180 min). Needlepoints corresponded to Shaohai (HT3) and Neiguan (PC6) on the heart and pericardium channel. BP and HR were monitored with an indwelling carotid catheter, and blood samples were taken from the jugular vein. Blood (for HPLC determination of NE and EPI), mean BP, and HR were sampled at rest and during the immobilization stress at 15, 30, 60, 90, 120, 150, and 180 min. Electroacupuncture at HT3 and PC6 points but not at control points (TE5, LI11, and tail) significantly reduced the expected increases in BP, HR, and attenuated plasma levels of NE and EPI in response to 3 h of immobilization stress. Results provide strong evidence that electroacupuncture effectively reduces BP and HR increases and plasma catecholamine increases in rats challenged with immobilization stress.

Studies of the central neural pathways to the stomach and Zusanli (ST36)

The purpose of this morphological study was to investigate the relation between the meridian, meridian points and viscera using neuroanatomical tracers. The common locations of the spinal cord and brain projecting to the stomach and Zusanli were observed following injection of CTB (cholera toxin B subunit) and pseudorabies viruses (PRV-Ba, Bartha strain and PRV-Ba-Gal, galactosidase insertion) into the stomach and Zusanli (ST36). After 4-5 days of survival following injection into twelve rats, they were perfused, and their spinal cords and brains were frozen sectioned (30 microm). These sections were stained by X-gal histochemical, CTB and PRV-Ba immunohistochemical staining methods, and examined with the light microscope. The results were as follows: Commonly labeled medulla oblongata regions were dorsal motor nucleus of vagus nerve (DMV), nucleus tractus solitarius (NTS) and area postrema (AP) following injection of CTB and PRV-Ba-Gal into stomach and Zusanli, respectively. In the spinal cord, commonly labeled neurons were found in thoracic, lumbar and sacral spinal segments. Densely labeled areas were found in lamina IV, V, VII (intermediolateral nucleus) and X of the spinal cord. In the brain, commonly labeled neurons were found in the Al noradrenalin cells/Cl adrenalin cells/caudoventrolateral reticular nucleus, dorsal motor nucleus of vagus nerve, nucleus tractus solitarius, area postrema, raphe obscurus nucleus, raphe pallidus nucleus, raphe magnus nucleus, gigantocellular nucleus, locus coeruleus, parabrachial nucleus, Kolliker-Fuse nucleus, A5 cell group, central gray matter, paraventricular hypothalamic nucleus, lateral hypothalamic nucleus, retrochiasmatic hypothalamic nucleus, bed nucleus of stria terminalis and amygdaloid nucleus. Thus central autonomic center project both to the stomach and Zusanli. These morphological results suggest that there is a commonality of CNS cell groups in brain controlling stomach (viscera) and Zusanli (limb).

The DELLA motif is essential for gibberellin-induced degradation of RGA

RGA and GAI are homologous genes that encode putative transcriptional regulators that repress gibberellin (GA) signaling in Arabidopsis. Previously we showed that the green fluorescent protein (GFP)-RGA fusion protein is localized to the nucleus in transgenic Arabidopsis, and expression of this fusion protein rescues the rga null mutation. The GA signal seems to derepress the GA response pathway by degrading the repressor protein RGA. The GA-insensitive, semidominant, semidwarf gai-1 mutant encodes a mutant protein with a 17-amino acid deletion within the DELLA domain of GAI. It was hypothesized that this mutation turns the gai protein into a constitutive repressor of GA signaling. Because the sequences missing in gai-1 are identical between GAI and RGA, we tested whether an identical mutation (rga-Delta 17) in the RGA gene would confer a phenotype similar to gai-1. We demonstrated that expression of rga-Delta 17 or GFP-(rga-Delta 17) under the control of the RGA promoter caused a GA-unresponsive severe dwarf phenotype in transgenic Arabidopsis. Analysis of the mRNA levels of a GA biosynthetic gene, GA4, showed that the feedback control of GA biosynthesis in these transgenic plants was less responsive to GA than that in wild type. Immunoblot and confocal microscopy analyses indicated that rga-Delta17 and GFP-(rga-Delta 17) proteins were resistant to degradation after GA application. Our results illustrate that the DELLA domain in RGA plays a regulatory role in GA-induced degradation of RGA. Deletion of this region stabilizes the rga-Delta 17 mutant protein, and regardless of the endogenous GA status rga-Delta 17 becomes a constitutively active repressor of GA signaling.

Characterization of a novel laccase produced by the wood-rotting fungus Phellinus ribis

The white-rot fungus Phellinus ribis produced a single form of laccase, which was purified to apparent electrophoretic homogeneity from cultures induced with 2,5-xylidine. This protein was a dimer, consisting of two subunits of 76 kDa as determined by sodium dodecyl sulfate-polyacrylamide gel electrophoresis. Carbohydrate analysis revealed that the enzyme contained about 28% carbohydrate content. The laccase appeared to be different from other known laccases by the UV-visible absorption spectrum analysis. One enzyme molecule contained one copper, one manganese, and two zinc atoms. The laccase showed optimal activity at pH 4.0-6.0, 5.0, and 6.0 with 2,6-dimethoxyphenol, ABTS [2,2'-azino-bis-(3-ethylbenzothiazoline-6-sulfonic acid)], and syringaldazine, respectively. The enzyme preferably oxidized dimethoxyphenol and aromatic amine compounds. The stability of the laccase was low at acidic pH, whereas it showed high stability at neutral pH and mild temperature. The N-terminal amino acid sequence revealed a very low homology with other microbial laccases. With some substrates, the addition of manganese and H2O2 resulted in a remarkable increase in the oxidation rate. Without an appropriate phenolic substrate, the enzyme could not oxidize Mn(II) in the presence of H2O2 or pyrophosphate.

Repressing a repressor: gibberellin-induced rapid reduction of the RGA protein in Arabidopsis

RGA (for repressor of ga1-3) and SPINDLY (SPY) are likely repressors of gibberellin (GA) signaling in Arabidopsis because the recessive rga and spy mutations partially suppressed the phenotype of the GA-deficient mutant ga1-3. We found that neither rga nor spy altered the GA levels in the wild-type or the ga1-3 background. However, expression of the GA biosynthetic gene GA4 was reduced 26% by the rga mutation, suggesting that partial derepression of the GA response pathway by rga resulted in the feedback inhibition of GA4 expression. The green fluorescent protein (GFP)-RGA fusion protein was localized to nuclei in transgenic Arabidopsis. This result supports the predicted function of RGA as a transcriptional regulator based on sequence analysis. Confocal microscopy and immunoblot analyses demonstrated that the levels of both the GFP-RGA fusion protein and endogenous RGA were reduced rapidly by GA treatment. Therefore, the GA signal appears to derepress the GA signaling pathway by degrading the repressor protein RGA. The effect of rga on GA4 gene expression and the effect of GA on RGA protein level allow us to identify part of the mechanism by which GA homeostasis is achieved.

Repressing a repressor: gibberellin-induced rapid reduction of the RGA protein in Arabidopsis

RGA (for repressor of ga1-3) and SPINDLY (SPY) are likely repressors of gibberellin (GA) signaling in Arabidopsis because the recessive rga and spy mutations partially suppressed the phenotype of the GA-deficient mutant ga1-3. We found that neither rga nor spy altered the GA levels in the wild-type or the ga1-3 background. However, expression of the GA biosynthetic gene GA4 was reduced 26% by the rga mutation, suggesting that partial derepression of the GA response pathway by rga resulted in the feedback inhibition of GA4 expression. The green fluorescent protein (GFP)-RGA fusion protein was localized to nuclei in transgenic Arabidopsis. This result supports the predicted function of RGA as a transcriptional regulator based on sequence analysis. Confocal microscopy and immunoblot analyses demonstrated that the levels of both the GFP-RGA fusion protein and endogenous RGA were reduced rapidly by GA treatment. Therefore, the GA signal appears to derepress the GA signaling pathway by degrading the repressor protein RGA. The effect of rga on GA4 gene expression and the effect of GA on RGA protein level allow us to identify part of the mechanism by which GA homeostasis is achieved.

Repressing a repressor: gibberellin-induced rapid reduction of the RGA protein in Arabidopsis

RGA (for repressor of ga1-3) and SPINDLY (SPY) are likely repressors of gibberellin (GA) signaling in Arabidopsis because the recessive rga and spy mutations partially suppressed the phenotype of the GA-deficient mutant ga1-3. We found that neither rga nor spy altered the GA levels in the wild-type or the ga1-3 background. However, expression of the GA biosynthetic gene GA4 was reduced 26% by the rga mutation, suggesting that partial derepression of the GA response pathway by rga resulted in the feedback inhibition of GA4 expression. The green fluorescent protein (GFP)-RGA fusion protein was localized to nuclei in transgenic Arabidopsis. This result supports the predicted function of RGA as a transcriptional regulator based on sequence analysis. Confocal microscopy and immunoblot analyses demonstrated that the levels of both the GFP-RGA fusion protein and endogenous RGA were reduced rapidly by GA treatment. Therefore, the GA signal appears to derepress the GA signaling pathway by degrading the repressor protein RGA. The effect of rga on GA4 gene expression and the effect of GA on RGA protein level allow us to identify part of the mechanism by which GA homeostasis is achieved.

Genotype, phenotype, and developmental biology of molar tooth characters

Primate molar shapes reflect developmental and ecological processes. Development may constrain as well as facilitate evolution of new tooth shapes, affecting how reliable dental characters are in phylogenetic studies. Much of the genetic machinery of development uses the same genes among different organs, including teeth, limbs, and feathers. Furthermore, within a tooth, the development of individual cusps repeatedly uses the same set of developmental genes, forming a "developmental module." The repeated activation of the developmental module can explain the cumulative variation in later-developing cusps. Therefore short, later-developing cusps may be evolvable but also more homoplastic. This patterning cascade mode of cusp development can be used to explain the variational properties of dental characters and character states related to cusp initiation. The developmental basis and variational properties of crown termination, cusp shape, and cusp configuration characters are currently less well understood. It is unlikely that there is a simple "gene to phenotype" map for dental characters. Rather, the whole cusp pattern is a product of a dynamic developmental program manifested in the activation of the developmental modules.

Serotypes and antimicrobial susceptibility in clinical isolates of Haemophilus influenzae from Korean children in prevaccination era

Fifty-five strains of Haemophilus influenzae recovered at a children's hospital in Korea from 1992 through 1997, were analyzed for serotype and antibiotic resistance. Antimicrobial susceptibility was tested by broth dilution method. Among the 55 strains, 26 were from normally sterile body fluids, of which 17 were from the immunocompetent children. Spectrum in the immunocompetent included meningitis (47%), bacteremic pneumonia (18%), and bacteremia without focus (35%). Three (12%) of 26 invasive infections were caused by non-type b: one type d and two type f. Nine of 29 non-sterile body fluid isolates belonged to one of encapsulted serotypes: four a, two c, one of each of b, d and e. Thirty two (58%) strains were resistant to ampicillin, and all of which produced beta-lactamase. All of the strains were highly susceptible to amoxicillin/clavulanate, cefixime, cefuroxime, azithromycin and ciprofloxacin, while 1 (2%), 7 (13%), 4 (7%) and 4 (7%) strains were intermediate to cefprozil, cefaclor, loracarbef, and clarithromycin, respectively. The serotype distribution of H. influenzae in Korean children is similar to those in developed countries before the introduction of Hib conjugate vaccine, and ampicillin resistance rate is among the highest published to date.

Pedunculated exogastric leiomyoblastoma presenting as a wandering abdominal mass

We report the imaging findings in a case of pedunculated exogastric leiomyoblastoma presenting as a wandering abdominal mass. Ultrasound and computed tomography showed a large, mixed solid and cystic mass in the peritoneal cavity. Computed tomography clearly showed that the mass was connected to the stomach by a narrow stalk. Small bowel follow-through showed subtle extrinsic indentation of the gastric body. The mass wandered from the right to the left side of the peritoneal cavity during various radiologic examinations.

Meniscal flounce on MR: correlation with arthroscopic or surgical findings

The purpose of this study was to investigate the frequency of the meniscal flounce on MR imaging in patients who underwent arthroscopy or open surgery due to symptoms related to internal derangement of the knee, and to investigate associated findings in patients with meniscal flounce by comparing and analyzing the findings from MR imaging and surgery. MR images obtained from 116 knees before surgery were reviewed retrospectively. Seven medial menisci showed buckled, wavy flounce on sagittal MR images. None of the lateral menisci showed flounce. We reviewed the surgical records of all seven patients and the videotapes of six of the patients undergoing arthroscopy or open surgery. The frequency of flounce on sagittal MR images was 6.0% in the medial meniscus and was completely absent in the lateral meniscus. On coronal MR images, the truncated appearance of the affected meniscus was demonstrated in five patients, and a valgus deformity was seen in three patients. Five patients showed a moderate to large amount of joint effusion. On MR imaging and in surgery, ligament injuries were found in six patients (six medial collateral ligament injuries, five anterior cruciate ligament injuries, and two posterior cruciate ligament injuries). Non-specific synovitis was found in the one remaining patient. In the surgery of all seven patients, no tears were found at the meniscus itself showing flounce. In conclusion, the meniscal flounce seen on sagittal MR imaging can be a rare appearance of a transient distortion of a normal meniscus due to a valgus deformity caused by a MCL tear and/or due to an external rotation induced by cruciate ligament injury or positioning of knee joint within the magnet. The meniscal flounce should be interpreted carefully because it frequently appears truncated on the coronal scan and can simulate a meniscal tear.

Phylogenetic analysis of Xylaria based on nuclear ribosomal ITS1-5. 8S-ITS2 sequences

To elucidate phylogenetic relationships of Xylaria, nuclear ribosomal ITS1-5.8S-ITS2 regions from 22 strains of 18 species were sequenced. Members of Xylaria formed a monophyletic group and proved to be phylogenetically homogeneous except for Xylaria cubensis. Species of the section Xylorugosa were divided into three groups and X. cubensis belonging to the section Xyloglossa developed an independent lineage from the section Xylorugosa. Groupings were partially congruent with the morphological taxonomy. The stromal structure, ascal apex, ectostromal surface, perithecial structure, stipe differentiation and the germ slit of ascospores were phylogenetically significant characters in grouping Xylaria.

Capillary electrophoresis of nonprotein and protein amino acids without derivatization

An efficient separation of eleven nonprotein amino acids (NPAAs) and three protein amino acids containing aromatic moieties was achieved by capillary electrophoresis without derivatization. The fourteen amino acids were well separated with a 100 mM sodium phosphate run buffer (pH 2.0) using a 57 cm fused-silica capillary (50 microm ID, 50 cm effective length) at 20 degrees C. With an electric field of 351 V/cm, the time needed for the separation was less than 20 min. Under optimum conditions, excellent linear responses were obtained in the concentration range of 5-100 microM, with the linear correlation coefficient ranging from 0.9785 or greater. The relative standard deviations of the migration times and the corrected peak areas were found to be 1.5-3.9% and 8.0-11.5%, respectively. In order to improve the limit of detection (LOD), simple stacking and large volume stacking using an EOF pump (LVSEP) methods were used. Improved LODs were about 300 nM in stacking and below 15 nM for five small NPAAs in LVSEP.

Anatase-Rutile Transition of Precipitated Titanium Oxide with Alcohol Rinsing

The effect of alcohol washing on the anatase-rutile transition of precipitated titanium oxide was investigated using X-ray powder diffraction, Fourier-transform IR spectroscopy, and thermogravimetry. Alcohol (butanol) rinsing accelerated the anatase-rutile transition of precipitated titanium oxide powder so that the onset temperature of transition decreased drastically from 800 degrees C for water-washed powder to 550 degrees C for alcohol-rinsed powder. Alternation of transition kinetics and mechanisms by rinsing media could be confirmed from the analysis of temperature and time dependence of rutile content. The attributability of the chemical state of anatase after crystallization, which contained H(2)O, OH, and organic residues, to the change of transition kinetics with alcohol rinsing will be discussed. Two mechanisms, the effect of residual organics and/or H(2)O(OH), could be suggested on the basis of analysis of the difference between chemical states of water-washed anatase and alcohol-rinsed powder. Copyright 2000 Academic Press.

Cusp patterning defect in Tabby mouse teeth and its partial rescue by FGF

Tabby is a mouse mutant characterized by deficient development of the ectodermal organs: teeth, hair, and a subset of glands. Ectodysplasin, the protein encoded by the Tabby gene, was recently identified as a novel TNF-like transmembrane protein but little is known about its function. We have examined the Tabby tooth phenotype in detail by analysis of the adult and embryonic teeth. Tabby first molars had an obvious defect in cusp patterning as the number of cusps was reduced and the buccal and lingual cusps were joined. The disturbance in development was first visible morphologically in the bud stage molar. The primary enamel knot in a cap stage Tabby tooth expressed all enamel knot markers analyzed but was smaller than wild type and the first pair of developing secondary enamel knots was fused. We propose that the Tabby tooth phenotype is due to growth retardation during early stages of development which leads to reduced signaling from the primary enamel knot, followed by deficient growth of the dental epithelium and lack of formation of the last developing secondary enamel knots. The ectodysplasin transcripts were expressed in the outer enamel epithelium and dental lamina. When cultured in vitro Tabby bud/cap stage molars formed fewer cusps than wild-type controls. This phenotype was not rescued by exogenously added EGF despite the previously proposed link between Tabby and EGF. Instead FGF-10 partially restored morphogenesis and stimulated the development of additional tooth cusps in cultured Tabby molars.

Self-organization of periodic patterns by dissociated feather mesenchymal cells and the regulation of size, number and spacing of primordia

Periodic patterning is a fundamental organizing process in biology. Using a feather reconstitution assay, we traced back to the initial stage of the patterning process. Cells started from an equivalent state and self-organized into a periodic pattern without previous cues or sequential propagation. When different numbers of dissociated mesenchymal cells were confronted with a piece of same-sized epithelium, the size of feather primordia remained constant, not the number or interbud spacing, suggesting size determination is intrinsic to dissociated cells. Increasing bone morphogenetic protein (BMP) receptor expression in mesenchymal cells decreased the size of primordia while antagonizing the BMP pathway with Noggin increased the size of primordia. A threshold number of mesenchymal cells with a basal level of adhesion molecules such as NCAM were sufficient to trigger the patterning process. The process is best visualized by the progressive restriction of beta-catenin transcripts in the epidermis. Therefore, feather size, number and spacing are modulated through the available morphogen ligands and receptors in the system.

Localization of putative stem cells in dental epithelium and their association with Notch and FGF signaling

The continuously growing mouse incisor is an excellent model to analyze the mechanisms for stem cell lineage. We designed an organ culture method for the apical end of the incisor and analyzed the epithelial cell lineage by 5-bromo-2'-deoxyuridine and DiI labeling. Our results indicate that stem cells reside in the cervical loop epithelium consisting of a central core of stellate reticulum cells surrounded by a layer of basal epithelial cells, and that they give rise to transit-amplifying progeny differentiating into enamel forming ameloblasts. We identified slowly dividing cells among the Notch1-expressing stellate reticulum cells in specific locations near the basal epithelial cells expressing lunatic fringe, a secretory molecule modulating Notch signaling. It is known from tissue recombination studies that in the mouse incisor the mesenchyme regulates the continuous growth of epithelium. Expression of Fgf-3 and Fgf-10 were restricted to the mesenchyme underlying the basal epithelial cells and the transit-amplifying cells expressing their receptors Fgfr1b and Fgfr2b. When FGF-10 protein was applied with beads on the cultured cervical loop epithelium it stimulated cell proliferation as well as expression of lunatic fringe. We present a model in which FGF signaling from the mesenchyme regulates the Notch pathway in dental epithelial stem cells via stimulation of lunatic fringe expression and, thereby, has a central role in coupling the mitogenesis and fate decision of stem cells.

The role of long range, local and direct signalling molecules during chick feather bud development involving the BMPs, follistatin and the Eph receptor tyrosine kinase Eph-A4

The development of the feather buds during avian embryogenesis is a classic example of a spacing pattern. The regular arrangement of feather buds is achieved by a process of lateral inhibition whereby one developing feather bud prevents the formation of similar buds in the immediate vicinity. Lateral inhibition during feather formation implicates a role of long range signalling during this process. Recent work has shown that BMPs are able to enforce lateral inhibition during feather bud formation. However these results do not explain how the feather bud escapes the inhibition itself. We show that this could be achieved by the expression of the BMP antagonist, Follistatin. Furthermore we show that local application of Follistatin leads to the development of ectopic feather buds. We suggest that Follistatin locally antagonises the action of the BMPs and so permits the cellular changes associated with feather placode formation. We also provide evidence for the role of short range signalling during feather formation. We have correlated changes in cellular morphology in feather placodes with the expression of the gene Eph-A4 which encodes a receptor tyrosine kinase that requires direct cell-cell contact for activation. We show that the expression of this gene precedes cellular reorganisation required for feather bud formation.

Lineage and pluripotentiality of epithelial precursor cells in developing chicken skin

How do epithelial cells in developing skin accommodate the constantly growing embryo? Where do cells in skin appendages come from? Are they derivatives of a single appendage stem cell, or are they polyclonal? Here we analyze these issues in developing chicken skin using a replication-defective virus carrying beta-galactosidase and DiI microinjections. The results demonstrate that in early skin, epithelial cells labelled near the spine show a parallel linear stripe distribution pattern that is perpendicular to the midline of the trunk. This is similar to the human lines of Blaschko, a linear pattern on the skin, which many skin nevoid or acquired disorders follow. In later skin, feather buds form and contain a mixture of labeled and unlabeled cells, attesting to their polyclonal origin. When cells are traced for shorter time intervals, the labeled progeny appear to follow certain rules. The degree of cell dispersion and mixing increases with a longer incubation period between the time of labeling and detection. The spatial maturation sequence of skin appendages is not regulated by the order in which epithelial cells are generated. Epithelial cells at this developmental stage are pluripotent and competent to respond to new signals to assume appropriate fates according to their micro-environment. The results suggest that local interactions act upon the originally linearly deposited pluripotential epithelial cells to form skin appendages.

EAF1 regulates vegetative-phase change and flowering time in Arabidopsis

We have identified a new locus that regulates vegetative phase change and flowering time in Arabidopsis. An early-flowering mutant, eaf1 (early flowering 1) was isolated and characterized. eaf1 plants flowered earlier than the wild type under either short-day or long-day conditions, and showed a reduction in the juvenile and adult vegetative phases. When grown under short-day conditions, eaf1 plants were slightly pale green and had elongated petioles, phenotypes that are observed in mutants altered in either phytochrome or the gibberellin (GA) response. eaf1 seed showed increased resistance to the GA biosynthesis inhibitor paclobutrazol, suggesting that GA metabolism and/or response had been altered. Comparison of eaf1 to other early-flowering mutants revealed that eaf1 shifts to the adult phase early and flowers early, similarly to the phyB (phytochrome B) and spy (spindly) mutants. eaf1 maps to chromosome 2, but defines a locus distinct from phyB, clf (curly leaf), and elf3 (early-flowering 3). These results demonstrate that eaf1 defines a new locus involved in an autonomous pathway and may affect GA regulation of flowering.

Wnt-7a in feather morphogenesis: involvement of anterior-posterior asymmetry and proximal-distal elongation demonstrated with an in vitro reconstitution model

How do vertebrate epithelial appendages form from the flat epithelia? Following the formation of feather placodes, the previously radially symmetrical primordia become anterior-posterior (A-P) asymmetrical and develop a proximo-distal (P-D) axis. Analysis of the molecular heterogeneity revealed a surprising parallel of molecular profiles in the A-P feather buds and the ventral-dorsal (V-D) Drosophila appendage imaginal discs. The functional significance was tested with an in vitro feather reconstitution model. Wnt-7a expression initiated all over the feather tract epithelium, intensifying as it became restricted first to the primordia domain, then to an accentuated ring pattern within the primordia border, and finally to the posterior bud. In contrast, sonic hedgehog expression was induced later as a dot within the primordia. RCAS was used to overexpress Wnt-7a in reconstituted feather explants derived from stage 29 dorsal skin to further test its function in feather formation. Control skin formed normal elongated, slender buds with A-P orientation, but Wnt-7a overexpression led to plateau-like skin appendages lacking an A-P axis. Feathers in the Wnt-7a overexpressing skin also had inhibited elongation of the P-D axes. This was not due to a lack of cell proliferation, which actually was increased although randomly distributed. While morphogenesis was perturbed, differentiation proceeded as indicated by the formation of barb ridges. Wnt-7a buds have reduced expression of anterior (Tenascin) bud markers. Middle (Notch-1) and posterior bud markers including Delta-1 and Serrate-1 were diffusely expressed. The results showed that ectopic Wnt-7a expression enhanced properties characteristic of the middle and posterior feather buds and suggest that P-D elongation of vertebrate skin appendages requires balanced interactions between the anterior and posterior buds.

Molecular phylogeny of Trametes and related genera

Mitochondrial small subunit ribosomal DNAs were sequenced and phylogenetically analyzed for Trametes and related genera of Ryvarden's Trametes group. Parsimony and distance analyses indicated that most of trimitic genera with white rotting habit of the Trametes group clustered within a single clade, suggesting that they may have originated from a common ancestor. The phylogenetic position and generic placement of Trametes consors was uncertain as yet. Trametes trogii grouped with Coriolopsis gallica and indicated that color of the basidiocarp is a poor character at generic level. Nucleotide differences between Daedaleopsis confragosa and D. tricolor were quite few and both species closely grouped together in a same clade, thus supporting that D. tricolor might be an ecotype of D. confragosa.

Inhibition of mast cell-dependent anaphylaxis by succinic acid

We have examined the effect of succinic acid on anaphylaxis. Succinic acid (100 mM) significantly inhibited systemic anaphylaxis induced by compound 48/80 in mice and dose-dependently inhibited local anaphylaxis activated by anti-dinitrophenyl IgE. Further 10 and 100 mM significantly inhibited histamine release from rat peritoneal mast cells activated by compound 48/80 or anti-dinitrophenyl IgE. In addition succinic acid (0.1 and 1 mM) had a significant inhibitory effect on anti-dinitrophenyl IgE-induced tumour necrosis factor-alpha secretion from rat peritoneal mast cells. The level of cyclic AMP in rat peritoneal mast cells, when succinic acid (100 mM) was added, transiently and significantly increased about 4 times compared with that of basal cells. These results suggest a possible use of succinic acid in managing mast cell-dependent anaphylaxis.

Shh, Bmp-2, Bmp-4 and Fgf-8 are associated with initiation and patterning of mouse tongue papillae

Spacing patterns are of fundamental importance in various repeated structures which develop at regular intervals such as feathers, teeth and insect ommatidia. The mouse tongue develops a regular papilla pattern and provides a good model to study pattern formation. We examined the expression patterns of the signalling molecules, sonic hedgehog (Shh), bone morphogenetic proteins -2 and -4 (Bmp-2 and Bmp-4), and fibroblast growth factor-8 (Fgf-8) in mouse embryos between E 10.5 and 15. We show that all four genes are expressed uniformly in the tongue epithelium between E 10.5 and 11. At E 13, before morphologically detectable gustatory papillae initiation, Shh, Bmp-2 and Bmp-4 expression segregates into discrete spots, whereas, Fgf-8 is downregulated. At E 14, small eminences in the anterior part of the tongue are the first morphological indications of fungiform papillae, and they express Shh and Bmp-2, whereas, Bmp-4 is almost absent in the tongue. We conclude that these conserved signalling molecules are associated with the initiation and early morphogenesis of the tongue papillae.