Effects of nutritional level on muscle development, histochemical properties of myofibre and collagen architecture in the pectoralis muscle of male broilers

1. The effects of nutritional level on muscle development, histochemical properties of myofibre and collagen architecture in the pectoralis muscle were evaluated using male broilers of Red Cornish x New Hampshire stock, reared on diets of high nutritional value for up to 80 d (H80d) and low nutritional value for up to 80 d (L80d, same age as H80d) or 95 d (L95d, same body weight as H80d). 2. The total live weight and the weight of pectoralis muscle were lower in L80d than in both H80d and L95d. The muscle weight as a percentage of live weight was 8.7% in L80d, 10.7% in H80d and 11.5% in L95d. 3. Pectoralis muscle was composed only of type IIB myofibres and showed no differences in myofibre type composition among the chicken groups. The largest diameter of type IIB myofibres was observed in L95d, followed by H80d and the smallest in L80d. 4. The total amount of intramuscular collagen did not differ among the chicken groups (1.92 to 1.99 mg/g). Types I and III collagens were immunohistochemically detected in both the perimysia and endomysia. The thin perimysia around the primary myofibre fascicles showed larger width in H80d than L80d and L95d, and also the thick perimysia around the secondary fascicles in H80d than L80d. 5. The collagen structure of the perimysium was most developed in H80d, followed by L95d and on the least in L80d. The development of perimysial collagen fibres could be enhanced by a rapid growth rate of the muscle induced by high nutritional level and depressed by a slow growth rate with low nutritional foods. 6. The endomysial collagen architecture was observed as a felt-like tissue of the fibril bundles with many slits. The thinnest endomysial wall was observed in L80d, followed by H80d and the thickest in L95d. 7. From these results, it was indicated that foods of high nutritional value could enhance growth of the pectoralis muscle of broilers, and this is accompanied by hypertrophy of the type IIB myofibres and development of the perimysial collagen architecture.

Age-related changes in the intramuscular distribution of melanocytes in the Silky fowl

1. The characteristics of melanocyte distribution in skeletal muscles in the Silky fowl were investigated in association with growth. 2. Pectoralis (PT) and iliotibialis lateralis (ITL) muscles from 1-, 3-, 5-, 10-, 20- and 30-week-old Silky males were weighed and collagen type I was detected in frozen sections immunohistochemically. 3. Melanocytes were observed in the collagen type I-immunopositive endomysium and perimysium in both muscles. 4. Image analysis indicated that the total area occupied by melanocytes in histological sections sharply decreased from 0.61% to 0.16% in PT muscle and from 1.67% to 0.33% in ITL muscle at 1 to 3 weeks, and then gradually decreased. The melanocyte area was larger in ITL muscle than in PT muscle until 10 weeks of age. 5. We concluded that the proportion of intramuscular melanocytes in the Silky fowl differs between types of muscles in the early stages of development, and it decreases with growth.

[Intraoperative frozen section diiagnosis of small peripheral lung adenocarcinoma for limited operation]

Sixty-two cases of peripheral lung adenocarcinoma 2 cm or less in diameter were diagnosed as type A, B, or C according to Noguchi classifications by intraoperative frozen section diagnosis. Four of 19 type A were changed finally to type B by postoperative pathologic examination. Likewise 10 of 34 type B were changed finally to 1 type A, 8 type C, and 1 type D. Three of 9 type C were changed finally to 2 type B and 1 type D. Frozen section diagnosis for small peripheral lung adenocarcinoma has some special problems and limitations. Only cases of type A diagnosed by frozen section diagnosis should be permitted to undergo limited surgical resection.

[Clinical experience with aortic connector system]

From April to December 2002, 40 patients underwent coronary artery bypass grafting (CABG) using the St. Jude Medical (Minneapolis) Symmetry bypass system (aortic connector system: ACS). 59 proximal anastomoses (51 saphenous vein grafts, 8 radial artery grafts) were performed with the ACS. One saphenous vein graft occluded during operation. Postoperative evaluation of the anastomotic patency was carried out by angiography in 45 grafts. Five of the saphenous vein grafts were occluded (5/38). One patient who was shock state before operation presented with postoperative unconsciousness. Another patient died at 8th postoperative day caused by ventricular fibrillation. We conclude that the ACS produces a simple, quick way of performing the proximal anastomosis without the need for clamping the aorta, allows reducing risk of embolization by aortic manipulation. However, it is necessary to discuss sufficiently using the ACS, because the graft patency with the ACS is lower than with standard suturing technique.

Growth changes of the collagen content and architecture in the pectoralis and iliotibialis lateralis muscles of cockerels

1. Growth changes of the collagen content and architecture in the pectoralis (PT) and iliotibialis lateralis (ITL) muscles were examined using cockerels from 1 to 14 weeks of age. 2. Total collagen content in PT muscle showed little change, but in ITL muscle reached a maximum at 5 weeks and thereafter decreased slightly until 14 weeks. The collagen content was markedly larger in ITL muscle after 5 weeks. Pyridinoline content of collagen increased abruptly from 5 to 14 weeks in both muscles, but no difference between muscle types was detected. 3. The cell size of the endomysial honeycombs increased with the development of myofibres, and the mesh size of the perimysium around the honeycombs enlarged. 4. In both muscles endomysia were an incomplete network of collagen fibrils with many foramina at one week, became a very thin membrane of felt-like fabric in 2 to 5 weeks and thereafter increased in thickness until 11 to 14 weeks. 5. Perimysial width around the secondary fasciculus differed between the muscle types after 5 weeks. In the wider perimysium of ITL muscle, the collagen fibres increased in number and size to make a stack of collagen bands around the fasciculus. In the narrower perimysium of PT muscle, a few platelets of collagen fibres also developed. 6. The perimysial collagen fibre at 1 to 2 weeks had a smooth surface and appeared to be composed of fine collagen fibrils. The fibre at 11 to 14 weeks showed a rugged surface and was composed of coarser collagen bundles that combined with each other into a net-like configuration with very slim meshes. 7. Our results showed that the collagenous components of chicken intramuscular connective tissue changed markedly during the early period of muscle growth in distribution, architecture and quality but with little difference in quantity.

Coffee consumption and glucose tolerance status in middle-aged Japanese men

AIMS/HYPOTHESIS

Several studies have reported that coffee has a protective effect against the development of type 2 diabetes. However, few of these studies used the standard glucose tolerance test to diagnose type 2 diabetes. The aim of this study was to investigate the relationship between coffee and green tea consumption and glucose tolerance status as determined using a 75-g OGTT.

METHODS

We performed a cross-sectional study of 3224 male officials of the self-defence forces. Glucose tolerance status was determined in accordance with the 1998 World Health Organization criteria, and average intakes of coffee and green tea over the previous year were assessed by a self-administered questionnaire. The figures obtained were adjusted for BMI, physical activity and other factors.

RESULTS

A total of 1130 men were identified as having glucose intolerance (IFG, IGT or type 2 diabetes). Compared with those who did not consume coffee on a daily basis, fasting and 2-h post-load plasma glucose levels were 1.5% and 4.3% lower in those who drank 5 cups of coffee or more per day respectively. The adjusted odds ratios of glucose intolerance for categories of <1, 1-2, 3-4 and >/=5 cups of coffee per day were 1.0 (referent), 0.8 (95% CI 0.6-1.0), 0.7 (95% CI 0.6-0.9) and 0.7 (95% CI 0.5-0.9) respectively (p=0.0001 for trend). No clear association was observed between green tea drinking and glucose tolerance status.

CONCLUSIONS/INTERPRETATION

Coffee consumption may inhibit postprandial hyperglycaemia and thereby protect against the development of type 2 diabetes mellitus.

Occurrence of aflatoxin M1in domestic milk in Japan during the winter season

A total of 208 samples of commercial pasteurized milk gathered from retail outlets across Japan during the winter season were analysed for aflatoxin M1 (AFM1). Japan was divided into 11 regions from north to south, and nine to 45 milk samples from each region were randomly purchased between December 2001 and February 2002. Each milk sample was cleaned up by an immunoaffinity column, and AFM1 was quantified by liquid chromatography with fluorescence detection in four independent laboratories. The limit of detection of the method was 0.001 microg kg(-1). The identity of the putative AFM1 in milk sample was confirmed by the formation of AFM1 hemi-acetal with trifluoroacetic acid. Based on the results obtained with spiked samples (0.05 microg AFM1 kg(-1)), the mean recovery was 91.4%, the relative standard deviation for repeatability was 4.6%, and the relative standard deviation for reproducibility was 8.0% among four independent laboratories. AFM1 was detected in 207 (99.5%) of 208 milk samples at 0.001-0.029 microg kg(-1), with a mean of 0.009 microg kg(-1) and a 90th percentile of 0.014 microg kg(-1). No significant difference of the level of AFM1 contamination was observed among the regions.

Developmental states of the collagen content, distribution and architecture in thepectoralis,iliotibialis lateralisandpuboischiofemoralismuscles of male Red Cornish × New Hampshire and normal broilers

1. Developmental states of the collagen content, distribution and architecture in the pectoralis (PT), iliotibialis lateralis (ITL) and puboischiofemoralis (PIF) muscles of male Red Cornish x New Hampshire (RN, 80 d, body weight 2.9 kg) and normal (3.1 kg) broilers were evaluated. 2. In PT muscle the total amount of collagen was significantly greater in RN broilers (3.33 mg/g) than in normal ones (1.71 mg/g). This higher collagen content in RN broilers was based mainly on the closer mesh sizes of endomysial honeycomb. The collagen structures in the perimysia also differed between broiler types, when more collagen fibres were observed in RN broilers. 3. ITL muscle contained total collagen of 4.10 to 5.00 mg/g. Types I and III collagens were distributed on the perimysia at higher percentages in RN broilers (31.6%, 37.2%) than normal (15.6%, 30.8%), respectively. The thick bands of tough collagen fibres characteristic of ITL muscle perimysium in cockerels had not yet developed in these broilers. 4. Total collagen was 4.63 to 6.29 mg/g in PIF material with fascia. In PIF muscle the perimysial collagen fibres had not yet attained their full growth but consisted of densely packed fibrils. PIF muscle was characterised by the earlier maturing collagen structure. 5. These results show that a perimysial collagen structure in broilers is still in an undeveloped state. It is supposed that tenderness of broiler meat is attributed mainly to characteristics of the collagen distribution, in which the majority of types I and III collagens is distributed on the closer mesh of endomysial honeycomb.

Exploitation of colinear relationships between the genomes of Lotus japonicus, Pisum sativum and Arabidopsis thaliana, for positional cloning of a legume symbiosis gene

The Lotus japonicus LjSYM2 gene, and the Pisum sativum orthologue PsSYM19, are required for the formation of nitrogen-fixing root nodules and arbuscular mycorrhiza. Here we describe the map-based cloning procedure leading to the isolation of both genes. Marker information from a classical AFLP marker-screen in Lotus was integrated with a comparative genomics approach, utilizing Arabidopsis genome sequence information and the pea genetic map. A network of gene-based markers linked in all three species was identified, suggesting local colinearity in the region around LjSYM2/PsSYM19. The closest AFLP marker was located just over 200 kb from the LjSYM2 gene, the marker SHMT, which was converted from a marker on the pea map, was only 7.9 kb away. The LjSYM2/PsSYM19 region corresponds to two duplicated segments of the Arabidopsis chromosomes AtII and AtIV. Lotus homologues of Arabidopsis genes within these segments were mapped to three clusters on LjI, LjII and LjVI, suggesting that during evolution the genomic segment surrounding LjSYM2 has been subjected to duplication events. However, one marker, AUX-1, was identified based on colinearity between Lotus and Arabidopsis that mapped in physical proximity of the LjSym2 gene.

Natural transformation of the thermophilic cyanobacterium Thermosynechococcus elongatus BP-1: a simple and efficient method for gene transfer

Proteins derived from the thermophilic cyanobacterium Thermosynechococcus elongatus BP-1, which performs plant-type oxygenic photosynthesis, are suitable for biochemical, biophysical and X-ray crystallographic studies. We found that T. elongatus displays natural transformation, and we established a simple and efficient protocol for transferring exogenous DNAs into the organism's genome. We obtained transformants directly on selective agar plates without having to amplify them prior to plating. We constructed several targeting vectors that enabled us to insert exogenous DNAs into specific sites without disrupting endogenous genes and operons. We also developed a new selectable marker gene for T. elongatus by optimizing the codons of the gene encoding a kanamycin nucleotidyltransferase derived from the thermophilic bacterium Bacillus stearothermophilus. This synthetic gene enabled us to select transformants as kanamycin-resistant colonies on agar plates at 52 degrees C. Optimization of the conditions for natural transformation resulted in a transformation efficiency of up to 1.7 x 10(3) transformants per microg of DNA. The exogenous DNAs were integrated stably into the targeted sites of the T. elongatus genome via homologous recombination by double crossovers.

Evolution and microsynteny of the apyrase gene family in three legume genomes

Apyrases have been suggested to play important roles in plant nutrition, photomorphogenesis, and nodulation. To help trace the evolution of these genes in the legumes--and possibly, the acquisition of new functions for nodulation--apyrase-containing BACs were sequenced from three legume genomes. Genomic sequences from Medicago truncatula, Glycine max and Lotus japonicus were compared to one another and to corresponding regions in Arabidopsis thaliana. A phylogenetic analysis of apyrase homologs from these regions and sequences from other legume species, as well as other plant families, identified a potentially legume-specific clade that contains a well-characterized soybean ( G. soja) apyrase, Gs52, as well as homologs from Dolichos, Lotus, Medicago and Pisum. Sister clades contain homologs from members of Brassicaceae, Solanaceae, Poaceae and Fabaceae. Comparisons of rates of change at synonymous and nonsynonymous sites in the Gs52 and sister clades show rapid evolution in the potentially legume-specific Gs52 clade. The genomic organization of the apyrase-containing BACs shows evidence of gene duplication, genomic rearrangement, and gene conversion among Gs52 homologs. Taken together, these results suggest a scenario of local apyrase gene duplication in an ancestor of the legumes, followed by functional diversification and increased rates of change in the new genes, and further duplications in the Galegae (which include the genera Medicago and Pisum). The study also provides a detailed comparison of genomic regions between two model genomes which are now being sequenced ( M. truncatulaand L. japonicus), and a genome from an economically important legume species ( G. max).

Comparison of collagen fibre architecture between slow-twitch cranial and fast-twitch caudal parts of broiler M. latissimus dorsi

1. Collagen fibre architectures of perimysium and endomysium in the slow-twitch cranial and fast-twitch caudal parts of broiler M. latissimus dorsi were compared. 2. Type I and III collagens were distributed in both perimysium and endomysium as indicated by their positive immunohistochemical reactions to polyclonal antibodies. 3. Cells invested by endomysium with no myofibres were larger in the cranial part because of the presence of larger slow-twitch myofibres. The honeycomb structure of endomysium was divided into several parts by thick perimysium. 4. The thick perimysial collagen fibres with parallel fibrils, which were interconnected by the loose reticular fibrils and thin fibres, were more numerous and thicker in the cranial part than the caudal. 5. Thick endomysial sidewall of cells in the cranial part was composed of a rougher reticulum of slightly thicker collagen fibrils compared with the thin sidewall in the caudal part. 6. These results indicated that both perimysial constitutions of collagen fibres and endomysial collagen fibrils had attained much larger growth in the slow-twitch cranial part than the fast-twitch caudal in broiler latissimus dorsi muscle.

Comparison of the histological and histochemical properties of skeletal muscles between carbon dioxide and electrically stunned chickens

1. Histological and histochemical profiles of Musculus pectoralis (PT, type IIB fibres), M. iliotibialis lateralis (ITL, types IIA + IIB fibres) and M. puboischiofemoralis pars medialis (PIF, type I fibres) were compared in carbon dioxide (37%, 70 s) and electrically (14 V, 5 s) stunned male chickens. 2. Muscle materials were taken at 0, 4 and 24 h from carcases dressed and cooled with ice-water mixture for 30 min. Glycogen and fat contents, and adenosine triphosphatase and reduced nicotinamide adenine dinucleotide dehydrogenase activities of fibres were measured. 3. In PT muscle at 0 h, gas stunned chickens showed many fibres with high glycogen content but those electrically stunned contained few such fibres. Fibres from gas stunned birds had lost almost all their glycogen after 24 h of cold storage. 4. In the ITL muscle of gas stunned chickens at 0 h residual glycogen was observed in type IIB fibres. In contrast, in the electrically stunned birds it was in type IIA, showing the different effects of the stunning methods. During cold storage, glycogen disappeared earlier in type IIB than IIA fibres. 5. In PIF muscle with fibres of low glycogen content, the gas stunned chickens maintained a good fibre structure for 4 h or more, but the electrically stunned had already lost intact fibre structure at 4 h. 6. These results indicated that the carbon dioxide stunning was a better method for chicken welfare and meat quality than electrical stunning.

Structural analysis of a Lotus japonicus genome. I. Sequence features and mapping of fifty-six TAC clones which cover the 5.4 mb regions of the genome

A total of 56 TAC clones with an average insert size of 100 kb were isolated from a TAC library of the Lotus japonicus genome based on the expressed sequences tags (ESTs), cDNA and gene information, and their nucleotide sequences were determined according to the shot-gun based strategy. The total length of the sequenced regions is 5,473,195 bp. By comparison with the sequences in protein and EST databases and analysis with computer programs for gene modeling, a total of 605 potential protein-encoding genes with known or predicted functions, 69 gene segments, and 172 pseudogenes were identified. The average density of the genes assigned so far is 1 gene/8120 bp. Introns were identified in approximately 78% of the potential genes. There was an average of 3.8 introns per gene and the average length of the introns was 375 bp. DNA markers were generated based on the nucleotide sequences obtained, and each clone was mapped onto the linkage map using the F2 mapping population derived from a cross of L. japonicus Gifu B-129 and Miyakojima MG-20. The sequence data, gene information and mapping information are available through the World Wide Web at http://www.kazusa.or.jp/lotus/.

Construction of a genetic linkage map of the model legume Lotus japonicus using an intraspecific F2 population

Among leguminous plants, the model legume Lotus japonicus (Regel) Larsen has many biological and genetic advantages. We have developed a genetic linkage map of L. japonicus based on amplified fragment length polymorphism (AFLP), simple sequence repeat polymorphism (SSRP) and derived cleaved amplified polymorphic sequence (dCAPS). The F2 mapping population used was derived from a cross between two L. japonicus accessions Gifu B-129 and Miyakojima MG-20. These parental accessions showed remarkable cytological differences, particularly with respect to size and morphology of chromosomes 1 and 2. Using fluorescence in situ hybridization (FISH) with BAC clones from Gifu B-129 and TAC (Transformation-competent Artificial Chromosome) clones from Miyakojima MG-20, a reciprocal translocation was found to be responsible for the cytological differences between chromosomes 1 and 2. The borders of the translocations were identified by FISH and by alignment toward the L. filicaulis x L. japonicus Gifu B-129 linkage map. The markers from the main translocated region were located on linkage groups 1 and 2 of the two accessions, Gifu B-129 and Miyakojima MG-20, respectively. The framework of the linkage map was constructed based on codominant markers, and then dominant markers were integrated separately in each linkage group of the parents. The resulting linkage groups correspond to the six pairs of chromosomes of L. japonicus and consist of 287 markers with 487.3 cM length in Gifu B-129 and 277 markers with 481.6 cM length in Miyakojima MG-20. The map and marker information is available through the World Wide Web at http://www.kazusa.or.jp/lotus/.

[Formation of ethyl carbamate in umeshu (plum liqueur)]

Samples of umeshu, a Japanese plum liqueur made from unripe plums, shochu and crystal sugar, were stored under fluorescent light, in the dark and in the refrigerator. The amount of ethyl carbamate formed in umeshu exposed to light or room temperature was larger than that in the dark or at low temperature. The amount of ethyl carbamate formed in umeshu to which cyanide had been added was larger than that in the absence of added cyanide. Thus, the amount of ethyl carbamate formed in the umeshu was increased by not only light and higher temperature, but also cyanide. Samples of model alcoholic beverages were stored under various conditions using red, yellow and blue cellophanes. The amount of ethyl carbamate formed in the model alcoholic beverage with blue cellophane was larger than in the cases of red and yellow cellophanes. It was found that the amount of ethyl carbamate formed in the model alcoholic beverage was increased by light in the wavelength range of 375-475 nm.

ARR1, a transcription factor for genes immediately responsive to cytokinins

Cytokinins are a class of phytohormones involved in various physiological events of plants. The Arabidopsis sensor histidine kinase CRE1 was recently reported to be a cytokinin receptor. We used a steroid-inducible system to show that the transcription factor-type response regulator ARR1 directs transcriptional activation of the ARR6 gene, which responds to cytokinins without de novo protein synthesis. This fact, together with characteristics of ARR1-overexpressing plants and arr1 mutant plants, indicates that the phosphorelay to ARR1, probably from CRE1, constitutes an intracellular signal transduction occurring immediately after cytokinin perception.

Treated natural history of superficial bladder cancer

BACKGROUND

The present study was conducted to examine the natural history of superficial bladder cancer.

METHODS

One hundred and forty-four patients with superficial bladder cancer who had been treated with transurethral resection of bladder tumor (TURBt) alone were analyzed.

RESULTS

The non-recurrence rate was 64.8% at 36 months and 61.2% at 60 months after TURBt. When the non-recurrence rate after TURBt was analyzed by background variables, the rate differed significantly between the solitary tumor group and the multiple tumor group. The tumor recurrence hazard curves for the entire population had one high peak before 500 days and another slight peak around 1500 days after TURBt.

CONCLUSIONS

These results will provide basic information useful when evaluating new regimens of intravesical instillation therapy for prophylaxis of superficial bladder cancer after our complete TURBt in the Nara Uro-Oncology Research Group.

Complete genomic sequence of the filamentous nitrogen-fixing cyanobacterium Anabaena sp. strain PCC 7120

The nucleotide sequence of the entire genome of a filamentous cyanobacterium, Anabaena sp. strain PCC 7120, was determined. The genome of Anabaena consisted of a single chromosome (6,413,771 bp) and six plasmids, designated pCC7120alpha (408,101 bp), pCC7120beta (186,614 bp), pCC7120gamma (101,965 bp), pCC7120delta (55,414 bp), pCC7120epsilon (40,340 bp), and pCC7120zeta (5,584 bp). The chromosome bears 5368 potential protein-encoding genes, four sets of rRNA genes, 48 tRNA genes representing 42 tRNA species, and 4 genes for small structural RNAs. The predicted products of 45% of the potential protein-encoding genes showed sequence similarity to known and predicted proteins of known function, and 27% to translated products of hypothetical genes. The remaining 28% lacked significant similarity to genes for known and predicted proteins in the public DNA databases. More than 60 genes involved in various processes of heterocyst formation and nitrogen fixation were assigned to the chromosome based on their similarity to the reported genes. One hundred and ninety-five genes coding for components of two-component signal transduction systems, nearly 2.5 times as many as those in Synechocystis sp. PCC 6803, were identified on the chromosome. Only 37% of the Anabaena genes showed significant sequence similarity to those of Synechocystis, indicating a high degree of divergence of the gene information between the two cyanobacterial strains.

Distinct constitutive and low-CO2-induced CO2 uptake systems in cyanobacteria: genes involved and their phylogenetic relationship with homologous genes in other organisms

Cyanobacteria possess a CO(2)-concentrating mechanism that involves active CO(2) uptake and HCO(3)(-) transport. For CO(2) uptake, we have identified two systems in the cyanobacterium Synechocystis sp. strain PCC 6803, one induced at low CO(2) and one constitutive. The low CO(2)-induced system showed higher maximal activity and higher affinity for CO(2) than the constitutive system. On the basis of speculation that separate NAD(P)H dehydrogenase complexes were essential for each of these systems, we reasoned that inactivation of one system would allow selection of mutants defective in the other. Thus, mutants unable to grow at pH 7.0 in air were recovered after transformation of a DeltandhD3 mutant with a transposon-bearing library. Four of them had tags within slr1302 (designated cupB), a homologue of sll1734 (cupA), which is cotranscribed with ndhF3 and ndhD3. The DeltacupB, DeltandhD4, and DeltandhF4 mutants showed CO(2)-uptake characteristics of the low CO(2)induced system observed in wild type. In contrast, mutants DeltacupA, DeltandhD3, and DeltandhF3 showed characteristics of the constitutive CO(2)-uptake system. Double mutants impaired in one component of each of the systems were unable to take up CO(2) and required high CO(2) for growth. Phylogenetic analysis indicated that the ndhD3/ndhD4-, ndhF3/ndhF4-, and cupA/cupB-type genes are present only in cyanobacteria. Most of the cyanobacterial strains studied possess the ndhD3/ndhD4-, ndhF3/ndhF4-, and cupA/cupB-type genes in pairs. Thus, the two types of NAD(P)H dehydrogenase complexes essential for low CO(2)-induced and constitutive CO(2)-uptake systems associated with the NdhD3/NdhF3/CupA-homologues and NdhD4/NdhF4/CupB-homologues, respectively, appear to be present in these cyanobacterial strains but not in other organisms.

Anion-mediated Fe3+ release mechanism in ovotransferrin C-lobe: a structurally identified SO4(2-) binding site and its implications for the kinetic pathway

The differential properties of anion-mediated Fe(3+) release between the N- and C-lobes of transferrins have been a focus in transferrin biochemistry. The structural and kinetic characteristics for isolated lobe have, however, been documented with the N-lobe only. Here we demonstrate for the first time the quantitative Fe(3+) release kinetics and the anion-binding structure for the isolated C-lobe of ovotransferrin. In the presence of pyrophosphate, sulfate, and nitrilotriacetate anions, the C-lobe released Fe(3+) with a decelerated rate in a single exponential progress curve, and the observed first order rate constants displayed a hyperbolic profile as a function of the anion concentration. The profile was consistent with a newly derived single-pathway Fe(3+) release model in which the holo form is converted depending on the anion concentration into a "mixed ligand" intermediate that releases Fe(3+). The apo C-lobe was crystallized in ammonium sulfate solution, and the structure determined at 2.3 A resolution demonstrated the existence of a single bound SO(4)(2-) in the interdomain cleft, which interacts directly with Thr(461)-OG1, Tyr(431)-OH, and His(592)-NE2 and indirectly with Tyr(524)-OH. The latter three groups are Fe(3+)-coordinating ligands, strongly suggesting the facilitated Fe(3+) release upon the anion occupation at this site. The SO(4)(2-) binding structure supported the single-pathway kinetic model.

Monitoring of methyl jasmonate-responsive genes in Arabidopsis by cDNA macroarray: self-activation of jasmonic acid biosynthesis and crosstalk with other phytohormone signaling pathways

Jasmonates mediate various physiological events in plant cells such as defense responses, flowering, and senescence through intracellular and intercellular signaling pathways, and the expression of a large number of genes appears to be regulated by jasmonates. In order to obtain information on the regulatory network of jasmonate-responsive genes (JRGs) in Arabidopsis thaliana (Arabidopsis), we screened 2880 cDNA clones for jasmonate responsiveness by a cDNA macroarray procedure. Since many of the JRGs reported so far have been identified in leaf tissues, the cDNA clones used were chosen from a non-redundant EST library that was prepared from above-ground organs. Hybridization to the filters was achieved using alpha-33P-labeled single-strand DNAs synthesized from mRNAs obtained from methyl jasmonate (MeJA)-treated and untreated Arabidopsis seedlings. Data analysis identified 41 JRGs whose mRNA levels were changed by more than three fold in response to MeJA. This was confirmed by Northern blot analysis by using eight representatives. Among the 41 JRGs identified, 5 genes were JA biosynthesis genes and 3 genes were involved in other signaling pathways (ethylene, auxin, and salicylic acid). These results suggest the existence of a positive feedback regulatory system for JA biosynthesis and the possibility of crosstalk between JA signaling and other signaling pathways.