bluuebunny/crossref_metadata_2025_split huggingface dataset:
DIFFERENTIAL DISPLAY OF TISSUE‐SPECIFIC MESSENGER RNAs IN PORPHYRA PERFORATA (RHODOPHYTA) THALLUS1
Authors: Hong Yong‐Ki , Sohn Chul Hyun , Polne‐Fuller Miriam. , Gibor Aharon 
Published: August 2006

ABSTRACT Various tissue‐specific markers in differentiated regions of the Porphyra perforata J. Agardh thallus were identified by comparing the differential display derived from RNA polymerase chain reaction (RNA‐PCR) with arbitrary primers. Total RNA was extracted by the LiCl‐guanidinium method from six regions of differentiated thallus: male tissue, female tissue, patch tissue, vegetative dividing tissue, vegetative non‐dividing tissue, and holdfast tissue. First‐strand cDNA was synthesized by reverse transcription of total RNA with random hexamers and amplified by PCR with arbitrary primers. The morphologically distinct regions of the differentiated tissue revealed the presence of tissue‐specific differential display of gene expression.
MORPHOLOGY AND PAEDOGAMOUS SEXUAL REPRODUCTION IN CHLOROGONIUM CAPILLATUM SP. NOV. (VOLVOCALES, CHLOROPHYTA)1
Authors: Nozaki Hisayoshi , Watanabe Makoto M. , Aizawa Kenichi 
Published: August 2006

ABSTRACT Morphology and sexual reproduction in Chlorogonium capillatum Nozaki, Watanabe & Aizawa sp. nov. (Volvocales, Chlorophyta) originating from Miyatoko Mire, Japan, were studied under controlled laboratory conditions. Vegetative cells of this new species were fusiform with blunt anterior and posterior ends, and they had a massive parietal chloroplast and numerous contractile vacuoles distributed throughout the protoplast. Several to many pyrenoids were randomly distributed in the chloroplast, but they disappeared under the light microscope when grown photoheterotrophically. During asexual reproduction, the first division took place transversely without a preceding rotation of the parental protoplast. In sexual reproduction, the parental protoplast divided successively to form 32 or 64 small, biflagellate isogametes. After gametogenesis, the gametes did not escape from the parental cell (gametangial) wall, within which pairs of the adjoining gametes fused to form quadriflagellate zygotes. Such zygotes were then released from the parental cell wall and developed into hypnozygotes, which at maturity developed numerous thin spines or hairs on the zygote wall. On zygote germination, four biflagellate germ cells were released from the zygote wall separately. This type of gametic union, “paedogamy,” has not previously been described in the green algae except for Chlorococcum echinozygotum Starr. Chlorogonium capillatum can be clearly distinguished from other described species of Chlorogonium by its numerous contractile vacuoles and blunt anterior and posterior ends in vegetative cells as well as by its unique sexual reproduction, in which paedogamous conjugation occurs, and numerous thin spines or hairs that develop on the hypnozygote walls.
Karyotypes of parasitic Hymenoptera: Diversity, evolution and taxonomic significance
Authors: GOKHMAN VLADIMIR E. 
Published: August 2006

AbstractHaploid chromosome numbers (n) of parasitic Hymenoptera (= traditional Parasitica + Chrysidoidea) vary from 2 to 23. However, this range can be subdivided into three intervals with n= 14–23 (less derived parasitic wasps, e.g., some Ichneumonidae and Braconidae as well as Gasteruptiidae), 8–13 (many other parasitic Hymenoptera) and 2–7 (Dryinidae, the majority of Chalcidoidea and some advanced Braconidae, e.g. Aphidiinae). The symmetric karyotype with a relatively high chromosome number (n= 14–17) and the prevalence of biarmed chromosomes must be considered as a groundplan feature of parasitic Hymenoptera. Independent reductions of chromosome numbers (n≤ 10–11) occurred in some groups of the superfamily Ichneumonoidea as well as in the common ancestor of the Proctotrupoidea sensu lato, Ceraphronoidea, Cynipoidea and Chalcidoidea. Further multiple decreases in chromosome numbers (n≤ 4–6) took place in some Braconidae, various lineages of the superfamily Chalcidoidea as well as in the family Dryinidae. Two main trends prevailed in the karyotype evolution of parasitic wasps: the reduction of chromosome numbers (mainly due to tandem fusions and less frequently due to centric ones) and karyotypic dissymmetrization (through an increase in size differentiation of chromosomes and/or in the share of acrocentrics in a chromosome set). Although karyotypic features of parasitic Hymenoptera can be used for solving taxonomic problems at various levels, this method is the most effective at the species level.
Enzymatic properties of phenoloxidase from Pieris rapae (Lepidoptera) larvae
Authors: XUE CHAO‐BIN , LUO WAN‐CHUN , CHEN QING‐XI , WANG QIN , KE LI‐NA 
Published: August 2006

AbstractThe kinetic parameters of partially purified phenoloxidase (PO, EC. 1.14.18.1) from the 5th instar larvae of Pieris rapae (Lepidoptera) were determined, using L‐3, 4‐dihydroxyphenylalanine (L‐DOPA) as substrate. The optimal pH and temperature of the enzyme for the oxidation of L‐DOPA were determined to be at pH 7.0 and at 42°C, respectively. The enzyme was stable between pH 6.5 and 7.4 and at temperatures lower than 37°C. At pH 6.8 and 37°C, the Michaelis constant (Km) and maximal velocity (Vm) of the enzyme for the oxidation of L‐DOPA were determined to be 0.80 μmol/L and 1.84 μmol/ L/min, respectively. Tetra‐hexylresorcinol and 4‐dodecylresorcinol effectively inhibited activity of phenoloxidase and this inhibition was reversible and competitive, with the IC50 of 1.50 and 1.12 μmol/L, respectively. The inhibition constants were estimated to be 0.50 and 0.47 μmol/L, respectively.
Female moths of cotton bollworm (Lepidoptera: Noctuidae) captured by waterbasin traps baited with synthetic female sex pheromone
Authors: SU JIAN‐WEI , WANG HONG‐TUO , GE FENG 
Published: August 2006

AbstractCotton bollworm, Helicoverpa armigera (Hübner) (Lepidoptera: Noctuidae), is one of the most important pest insects in cotton fields in China. Female moths were captured by waterbasin traps with a synthetic female sex pheromone blend in cotton fields over three years. The blend contained (Z)‐11‐hexadecenal and (Z)‐9‐hexadecenal with a ratio of 97:3. Each pheromone dispenser was impregnated with 2.0 mg of pheromone blend and 0.2 mg of antioxidant dissolved with 0.1 mL of hexane, and there was a control dispenser with a similar amount of antioxidant and solvent only. Waterbasin traps were deployed in three configurations in the fields. ‘A’ was pheromone traps only, ‘B’ was both pheromone and control traps, ‘C’ was control traps only. (i) In four plots of ‘A’, the average weekly female catch was 1.5, and more females were captured by centrally located pheromone traps, (ii) In three plots of ‘Brsquo;, control traps also captured female as well as male moths, but average weekly female catches of control traps was significantly lower than that in pheromone‐baited traps. (iii) There were significant linear relationships between the average weekly female catch and the corresponding layer in pheromone‐baited traps in both ‘A’ and ‘B’ plots, and in quadratic equations in control in ‘B’ plots. (iv) With the increase of the interval of traps, average weekly female catches per trap increased but average weekly female catches per hectare decreased. (v) Among the female moths captured by pheromone traps, 88.3% were mated female moths which each containing 1.46 spermatophores, while in control traps 86.9% of the mated female moths had 0.90 spermatophores. There was a significant difference between the average numbers of spermatophores of mated females in pheromone traps and in controls.
The discovery of the genus Indabracon van Achterberg (Hymenoptera: Braconidae: Braconinae) in China, with description of one new species
Authors: YANG JIAN‐QUAN , CHEN JIA‐HUA , LIU JUAN‐JUAN 
Published: August 2006

AbstractThe genus Indabracon van Achterberg, 1993 was discovered in China, and one new species (I. bicolor sp. nov.) of this genus is fully described and illustrated in the present paper. A key to the species of the genus is provided. The new species is similar to the Indian species I. trimaculatus (Cameron, 1900) structurally, but differs for example by: basal half of pterostigma yellow; apical half dark brown; smooth postero‐lateral area of the third tergite rather small; propodeum with belt of setae dorsally and lamelliform carinae posteriorly; ovipositor sheath approximately 0.60 times the forewing, somewhat longer than metasoma; the first tergite surface distinctly carinate and rugose, especially in its medial area and laterally. The type specimens are deposited in the Beneficial Insects Lab, College of Plant Protection, Fujian Agriculture & Forestry University, China.
Forearm plethysmography in the assessment of vascular tone and resistance vasculature design: new methodological insights
Authors: Mathiassen O. N. , Buus N. H. , Olsen H. W. , Larsen M. L. , Mulvany M. J. , Christensen K. L. 
Published: August 2006

AbstractAim:  High peripheral resistance and structural alteration in resistance arteries are central phenomena in essential hypertension and have been widely examined by forearm venous occlusion plethysmography; at rest for studying vascular tone, and during reactive hyperaemia for studying vascular structure. This work concerns the influence of venous pressure on hyperaemic vascular resistance (Rmin), the reproducibility of hyperaemic and resting vascular resistances (Rrest) and the relation between forearm and total peripheral vascular resistance (TPR).Methods:  In four healthy subjects, intravenous and intra‐arterial blood pressures were measured simultaneously with plethysmographic recordings of hyperaemic and resting forearm blood flows. Reproducibility was examined in 15 young and 14 middle‐aged healthy subjects and in 21 untreated hypertensive patients.Results:  R
min remained low in the first recorded cardiac cycle, but rose in the second, even though corrected for the venous pressure rise, suggesting vascular tone recovery along with venous congestion. Between‐day reproducibility of Rmin was high in middle‐aged normotensive (8.7%) and hypertensive subjects (10.6%), but Rmin fell significantly between successive days in the young subjects. Rrest correlated with TPR, but required up to 40 min to reach steady state and showed high day‐to‐day variation in young (21.8%) and hypertensive subjects (16.2%).Conclusions:  During hyperaemia, vascular resistance should be measured in the first cardiac cycle following venous occlusion to minimize influences of venous pressure rise and possible tone recovery. Rrest seems to reflect TPR. About 20 subjects may be needed to detect 15% changes between days in Rrest, fewer when concerning Rmin and TPR.
Analysis of Mitogen-Activated Protein Kinase Signaling Specificity in Response to Hyperosmotic Stress: Use of an Analog-Sensitive
HOG1
Allele
Authors: Westfall Patrick J. , Thorner Jeremy 
Published: August 2006

ABSTRACT

When confronted with a marked increase in external osmolarity, budding yeast (
Saccharomyces cerevisiae
) cells utilize a conserved mitogen-activated protein kinase (MAPK) signaling cascade (the high-osmolarity glycerol or HOG pathway) to elicit cellular responses necessary to permit continued growth. One input that stimulates the HOG pathway requires the integral membrane protein and putative osmosensor Sho1, which recruits and enables activation of the MAPK kinase kinase Ste11. In mutants that lack the downstream MAPK kinase (
pbs2
Δ) or the MAPK (
hog1
Δ) of the HOG pathway, Ste11 activated by hyperosmotic stress is able to inappropriately stimulate the pheromone response pathway. This loss of signaling specificity is known as cross talk. To determine whether it is the Hog1 polypeptide per se or its kinase activity that is necessary to prevent cross talk, we constructed a fully functional analog-sensitive allele of
HOG1
to permit acute inhibition of this enzyme without other detectable perturbations of the cell. We found that the catalytic activity of Hog1 is required continuously to prevent cross talk between the HOG pathway and both the pheromone response and invasive growth pathways. Moreover, contrary to previous reports, we found that the kinase activity of Hog1 is necessary for its stress-induced nuclear import. Finally, our results demonstrate a role for active Hog1 in maintaining signaling specificity under conditions of persistently high external osmolarity.
Antagonism between Two Mechanisms of Antifungal Drug Resistance
Authors: Anderson James B. , Ricker Nicole , Sirjusingh Caroline 
Published: August 2006

ABSTRACT

This study tested for interaction between two independently evolved mechanisms of fluconazole resistance in
Saccharomyces cerevisiae
. One set of strains was from a 400-generation evolution experiment, during which the concentration of fluconazole was increased from 16 to 256 μg/ml in four increments. At 100 generations, populations became fixed for resistance mutations in either of two transcriptional regulators,
PDR1
or
PDR3
. At 400 generations, replicate populations became fixed for another resistance mutation in
UNK1
, an unmapped gene further increasing resistance. Another genotype used in this study came from a population placed initially in 128 μg/ml of fluconazole; this environment selects for resistance through loss of function at
ERG3
, resulting in altered sterol metabolism. Mutant strains carrying
PDR1
r
or
PDR3
r
were crossed with the
erg3
r
mutant strain, and the doubly mutant, haploid offspring were identified. The double-mutant strains grew less well than the parent strains at all concentrations of fluconazole tested. In genome-wide assays of gene expression, several ABC transporter genes that were overexpressed in one parent and several
ERG
genes that were overexpressed in the other parent were also overexpressed in the double mutants. Of the 43 genes that were consistently overexpressed in the
PDR1
r
parents at generation 100, however, 31 were not consistently overexpressed in the double mutants. Of these 31 genes, 30 were also not consistently overexpressed after a further 300 generations of evolution in the
PDR1
r
parent populations. The two independently evolved mechanisms of fluconazole resistance are strongly antagonistic to one another.
Eukaryotic Release Factor 1 Phosphorylation by CK2 Protein Kinase Is Dynamic but Has Little Effect on the Efficiency of Translation Termination inSaccharomyces cerevisiae
Authors: Kallmeyer Adam K. , Keeling Kim M. , Bedwell David M. 
Published: August 2006

ABSTRACTProtein synthesis requires a large commitment of cellular resources and is highly regulated. Previous studies have shown that a number of factors that mediate the initiation and elongation steps of translation are regulated by phosphorylation. In this report, we show that a factor involved in the termination step of protein synthesis is also subject to phosphorylation. Our results indicate that eukaryotic release factor 1 (eRF1) is phosphorylated in vivo at serine 421 and serine 432 by the CK2 protein kinase (previously casein kinase II) in the budding yeastSaccharomyces cerevisiae. Phosphorylation of eRF1 has little effect on the efficiency of stop codon recognition or nonsense-mediated mRNA decay. Also, phosphorylation is not required for eRF1 binding to the other translation termination factor, eRF3. In addition, we provide evidence that the putative phosphatase Sal6p does not dephosphorylate eRF1 and that the state of eRF1 phosphorylation does not influence the allosuppressor phenotype associated with asal6Δ mutation. Finally, we show that phosphorylation of eRF1 is a dynamic process that is dependent upon carbon source availability. Since many other proteins involved in protein synthesis have a CK2 protein kinase motif near their extreme C termini, we propose that this represents a common regulatory mechanism that is shared by factors involved in all three stages of protein synthesis.
Characterization and Developmentally Regulated Localization of the Mitochondrial Carrier Protein Homologue MCP6 from
Trypanosoma brucei
Authors: Colasante Claudia , Alibu Vincent P. , Kirchberger Simon , Tjaden Joachim , Clayton Christine , Voncken Frank 
Published: August 2006

ABSTRACT

Proteins of the mitochondrial carrier family (MCF) are located mainly in the inner mitochondrial membrane and mediate the transport of a large range of metabolic intermediates. The genome of
Trypanosoma brucei
harbors 29 genes encoding different MCF proteins. We describe here the characterization of MCP6, a novel
T. brucei
MCF protein. Sequence comparison and phylogenetic reconstruction revealed that MCP6 is closely related to different mitochondrial ADP/ATP and calcium-dependent solute carriers, including the ATP-Mg/Pi carrier of
Homo sapiens
. However, MCP6 lacks essential amino acids and sequence motifs conserved in these metabolite transporters, and functional reconstitution and transport assays with
E. coli
suggested that this protein indeed does not function as an ADP/ATP or ATP-Mg/Pi carrier. The subcellular localization of MCP6 is developmentally regulated: in bloodstream-form trypanosomes, the protein is predominantly glycosomal, whereas in the procyclic form, it is found mainly in the mitochondria. Depletion of MCP6 in procyclic trypanosomes resulted in growth inhibition, an increased cell size, aberrant numbers of nuclei and kinetoplasts, and abnormal kinetoplast morphology, suggesting that depletion of MCP6 inhibits division of the kinetoplast.
Spo5/Mug12, a Putative Meiosis-Specific RNA-Binding Protein, Is Essential for Meiotic Progression and Forms Mei2 Dot-Like Nuclear Foci
Authors: Kasama Takashi , Shigehisa Akira , Hirata Aiko , Saito Takamune T. , Tougan Takahiro , Okuzaki Daisuke , Nojima Hiroshi 
Published: August 2006

ABSTRACT

We report here a functional analysis of
spo5
+
(
mug12
+
)
of
Schizosaccharomyces pombe
, which encodes a putative RNA-binding protein. The disruption of
spo5
+
caused abnormal sporulation, generating inviable spores due to failed forespore membrane formation and the absence of a spore wall, as determined by electron microscopy. Spo5 regulates the progression of meiosis I because
spo5
mutant cells display normal premeiotic DNA synthesis and the timely initiation of meiosis I but they show a delay in the peaking of cells with two nuclei, abnormal tyrosine 15 dephosphorylation of Cdc2, incomplete degradation of Cdc13, retarded formation and repair of double strand breaks, and a reduced frequency of intragenic recombination. Immunostaining showed that Spo5-green fluorescent protein (GFP) appeared in the cytoplasm at the horsetail phase, peaked around the metaphase I to anaphase I transition, and suddenly disappeared after anaphase II. Images of Spo5-GFP in living cells revealed that Spo5 forms a dot in the nucleus at prophase I that colocalized with the Mei2 dot. Unlike the Mei2 dot, however, the Spo5 dot was observed even in
sme2Δ
cells. Taken together, we conclude that Spo5 is a novel regulator of meiosis I and that it may function in the vicinity of the Mei2 dot.
Effects of Depleting the Essential Central Metabolic Enzyme Fructose-1,6-Bisphosphate Aldolase on the Growth and Viability of
Candida albicans
: Implications for Antifungal Drug Target Discovery
Authors: Rodaki Alexandra , Young Tim , Brown Alistair J. P. 
Published: August 2006

ABSTRACT

The central metabolic enzyme fructose-1,6-bisphosphate aldolase (Fba1p) catalyzes a reversible reaction required for both glycolysis and gluconeogenesis. Fba1p is a potential antifungal target because it is essential in yeast and because fungal and human aldolases differ significantly. To test the validity of Fba1p as an antifungal target, we have examined the effects of depleting this enzyme in the major fungal pathogen
Candida albicans
. Using a methionine/cysteine-conditional mutant (
MET3-FBA1/fba1
), we have shown that Fba1p is required for the growth of
C. albicans
. However, Fba1p must be depleted to below 5% of wild-type levels before growth is blocked. Furthermore, Fba1p depletion exerts static rather than cidal effects upon
C. albicans
. Fba1p is a relatively abundant and stable protein in
C. albicans
, and hence, Fba1p levels decay relatively slowly following
MET3-FBA1
shutoff. Taken together, our observations can account for our observation that the virulence of
MET3-FBA1/fba1
cells is only partially attenuated in the mouse model of systemic candidiasis. We conclude that an antifungal drug directed against Fba1p would have to be potent to be effective.
Heterologous Expression Implicates a GATA Factor in Regulation of Nitrogen Metabolic Genes and Ion Homeostasis in the Halotolerant Yeast
Debaryomyces hansenii
Authors: García-Salcedo Raúl , Casamayor Antonio , Ruiz Amparo , González Asier , Prista Catarina , Loureiro-Dias Maria C. , Ramos José , Ariño Joaquín 
Published: August 2006

ABSTRACT

The yeast
Debaryomyces hansenii
has a remarkable capacity to proliferate in salty and alkaline environments such as seawater. A screen for
D. hansenii
genes able to confer increased tolerance to high pH when overexpressed in
Saccharomyces cerevisiae
yielded a single gene, named here Dh
GZF3
, encoding a putative negative GATA transcription factor related to
S. cerevisiae
Dal80 and Gzf3. Overexpression of this gene in wild-type
S. cerevisiae
increased caffeine and rapamycin tolerance, blocked growth in low glucose concentrations and nonfermentable carbon sources, and resulted in lithium- and sodium-sensitive cells. Sensitivity to salt could be attributed to a reduced cation efflux, most likely because of a decrease in expression of the
ENA1
Na
+
-ATPase gene. Overexpression of Dh
GZF3
did not affect cell growth in a
gat1
mutant but was lethal in the absence of Gln3. These are positive factors that oppose both Gzf3 and Dal80. Genome-wide transcriptional profiling of wild-type cells overexpressing Dh
GZF3
shows decreased expression of a number of genes that are usually induced in poor nitrogen sources. In addition, the entire pathway leading to Lys biosynthesis was repressed, probably as a result of a decrease in the expression of the specific Lys14 transcription factor. In conclusion, our results demonstrate that DhGzf3 can play a role as a negative GATA transcription factor when expressed in
S. cerevisiae
and that it most probably represents the only member of this family in
D. hansenii
. These findings also point to the GATA transcription factors as relevant elements for alkaline-pH tolerance.