113 research outputs found
Narrowing Down the Mapping of Plant Sex-Determination Regions Using New Y-Chromosome-Specific Markers and Heavy-Ion Beam Irradiation-Induced Y-Deletion Mutants in Silene latifolia
Silene latifolia is a well-studied model system for plant XY sex determination. Three maleness factors are thought to function on the Y chromosome, gynoecium suppression factor (GSF), stamen-promoting factor (SPF), and male fertility factor (MFF), and their deletions result in hermaphrodites, anther defects, and pollen defects, respectively. Although a framework map of the Y chromosome exists, the sex determination genes have not been identified, and no markers close enough to potentially be used for BAC library screening are yet available. The analysis of Y deletion mutants by Y-chromosome-specific STS markers is an efficient way to isolate sex determination regions, but more Y-specific STS markers are needed to accelerate the exploration of sex determination factors. Herein, we report a marker design method that uses simple sequence repeats, which is especially effective on the Y chromosome of S. latifolia because it contains many simple sequence repeats. Six new Y-chromosome-specific STS markers were obtained, SmicSy1–6. These were used to detect relatively small Y deletion sites in heavy-ion beam irradiation-induced mutants. The mapping of male sex determination regions was narrowed down by using more markers and smaller-sized Y deletion mutants. One new marker, SmicSy6, is a proximal marker to SPF and, thus, a second index for SPF. The region including SPF is thought to be located between two SPF proximal markers. The flower phenotype correlates with the deletion size of SPF using SPF proximal markers. These findings represent new progress in isolating the sex determination factor, which has been studied for more than 50 years
Relationship between starch and lipid accumulation induced by nutrient depletion and replenishment in the microalga Parachlorella kessleri
Photosynthetic carbon partitioning into starch and neutral lipids, as well as the influence of nutrient depletion and replenishment on growth, pigments and storage compounds, were studied in the microalga, Parachlorella kessleri. Starch was utilized as a primary carbon and energy storage compound, but nutrient depletion drove the microalgae to channel fixed carbon into lipids as secondary storage compounds. Nutrient depletion inhibited both cellular division and growth and caused degradation of chlorophyll. Starch content decreased from an initial value of 25, to around 10% of dry weight (DW), while storage lipids increased from almost 0 to about 29% of DW. After transfer of cells into replenished mineral medium, growth, reproductive processes and chlorophyll content recovered within 2 days, while the content of both starch and lipids decreased markedly to 3 or less % of DW; this suggested that they were being used as a source of energy and carbon.This study was supported by grant CREST of Japan Science and Technology Agency, by Grant No. LH12145 of Ministry of Education, Youth and Sports of the Czech Republic, by Grant for International Collaboration Academy of Sciences of the Czech Republic No. M200201205 and by the Technology Agency of the Czech Republic, project No. TE01020080
Prediction of functional recovery after revascularization using quantitative gated myocardial perfusion SPECT: a multi-center cohort study in Japan
金沢大学医薬保健研究域医学系Backgrounds: Prediction of left ventricular functional recovery is important after myocardial infarction. The impact of quantitative perfusion and motion analyses with gated single-photon emission computed tomography (SPECT) on predictive ability has not been clearly defined in multi-center studies. Methods: A total of 252 patients with recent myocardial infarction (n = 74) and old myocardial infarction (n = 175) were registered from 25 institutions. All patients underwent resting gated SPECT using 99mTc-hexakis-2-methoxy-isobutyl isonitrile (MIBI) and repeated the study after revascularization after an average follow-up period of 132 ± 81 days. Visual and quantitative assessment of perfusion and wall motion were performed in 5,040 segments. Results: Non-gated segmental percent uptake and end-systolic (ES) percent uptake were good predictors of wall motion recovery and significantly differed between improved and non-improved groups (66 ± 17% and 55 ± 18%, p < 0.0001 for non-gated; 64 ± 16% and 51 ± 17% for ES percent uptake, p < 0.0001). The area under the curve of receiver operating characteristics curve for non-gated percent uptake, ES percent uptake, end-diastolic percent uptake and visual perfusion defect score was 0.70, 0.71, 0.61, and 0.56, respectively. Sensitivity and specificity of percent uptake were 68% and 64% for non-gated map and 80% and 52% for ES percent uptake map. An optimal threshold for predicting segmental improvement was 63% for non-gated and 52% for ES percent uptake values. Conclusion: Segmental 99mTc-MIBI uptake provided a useful predictor of wall motion improvement. Application of quantitative approach with non-gated and ES percent uptake enhanced predictive accuracy over visual analysis particularly in a multi-center study. © 2008 Springer-Verlag
Genomic structure and evolution of the mating type locus in the green seaweed Ulva partita
The evolution of sex chromosomes and mating loci in organisms with UV systems of sex/mating type determination in haploid phases via genes on UV chromosomes is not well understood. We report the structure of the mating type (MT) locus and its evolutionary history in the green seaweed Ulva partita, which is a multicellular organism with an isomorphic haploid-diploid life cycle and mating type determination in the haploid phase. Comprehensive comparison of a total of 12.0 and 16.6 Gb of genomic next-generation sequencing data for mt− and mt+ strains identified highly rearranged MT loci of 1.0 and 1.5 Mb in size and containing 46 and 67 genes, respectively, including 23 gametologs. Molecular evolutionary analyses suggested that the MT loci diverged over a prolonged period in the individual mating types after their establishment in an ancestor. A gene encoding an RWP-RK domain-containing protein was found in the mt− MT locus but was not an ortholog of the chlorophycean mating type determination gene MID. Taken together, our results suggest that the genomic structure and its evolutionary history in the U. partita MT locus are similar to those on other UV chromosomes and that the MT locus genes are quite different from those of Chlorophyceae
A novel clinical entity, IgG4-related disease (IgG4RD): general concept and details
IgG4-related disease (IgG4RD) is a novel clinical disease entity characterized by elevated serum IgG4 concentration and tumefaction or tissue infiltration by IgG4-positive plasma cells. IgG4RD may be present in a certain proportion of patients with a wide variety of diseases, including Mikulicz’s disease, autoimmune pancreatitis, hypophysitis, Riedel thyroiditis, interstitial pneumonitis, interstitial nephritis, prostatitis, lymphadenopathy, retroperitoneal fibrosis, inflammatory aortic aneurysm, and inflammatory pseudotumor. Although IgG4RD forms a distinct, clinically independent disease category and is attracting strong attention as a new clinical entity, many questions and problems still remain to be elucidated, including its pathogenesis, the establishment of diagnostic criteria, and the role of IgG4. Here we describe the concept of IgG4RD and up-to-date information on this emerging disease entity
Factors in glucocorticoid regimens associated with treatment response and relapses of IgG4-related disease: a multicentre study
Glucocorticoids (GC) are effective for treating IgG4-related disease (IgG4-RD); however, relapse is often observed. We conducted a retrospective multicentre study to investigate risk factors in GC regimens associated with relapses of IgG4-RD. Data on 166 patients with definitive IgG4-RD diagnosis were collected from 12 institutions. Comprehensive surveillance of clinical backgrounds and GC regimens as well as multivariate analysis of factors associated with treatment responses and relapses was performed. To determine the initial maximal GC dose, the patients were stratified into three groups depending on the initial prednisolone (PSL) dosage: 0.7 mg/kg/day. The multivariate analysis extracted the disease duration and reduction speed of initial GC dose. Patients treated with initial GC 0.7 mg/kg/day of PSL showed higher relapse rates than those treated with 0.4–0.69 mg/kg/day. The relapse rates were significantly higher in patients with fast reduction of the initial dose (>0.4 mg/day) than in patients with slow reduction (<0.4 mg/day). To avoid relapse, 0.4–0.69 mg/kg/day of initial PSL with slow reduction speed (<0.4 mg/day) is needed in the early treatment of IgG4-RD
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Consensus Statement on the Pathology of IgG4-Related Disease
IgG4-related disease is a newly recognized fibro-inflammatory condition characterized by several features: a tendency to form tumefactive lesions in multiple sites; a characteristic histopathological appearance; and—often but not always—elevated serum IgG4 concentrations. An international symposium on IgG4-related disease was held in Boston, MA, on 4–7 October 2011. The organizing committee comprising 35 IgG4-related disease experts from Japan, Korea, Hong Kong, the United Kingdom, Germany, Italy, Holland, Canada, and the United States, including the clinicians, pathologists, radiologists, and basic scientists. This group represents broad subspecialty expertise in pathology, rheumatology, gastroenterology, allergy, immunology, nephrology, pulmonary medicine, oncology, ophthalmology, and surgery. The histopathology of IgG4-related disease was a specific focus of the international symposium. The primary purpose of this statement is to provide practicing pathologists with a set of guidelines for the diagnosis of IgG4-related disease. The diagnosis of IgG4-related disease rests on the combined presence of the characteristic histopathological appearance and increased numbers of IgG4+ plasma cells. The critical histopathological features are a dense lymphoplasmacytic infiltrate, a storiform pattern of fibrosis, and obliterative phlebitis. We propose a terminology scheme for the diagnosis of IgG4-related disease that is based primarily on the morphological appearance on biopsy. Tissue IgG4 counts and IgG4:IgG ratios are secondary in importance. The guidelines proposed in this statement do not supplant careful clinicopathological correlation and sound clinical judgment. As the spectrum of this disease continues to expand, we advocate the use of strict criteria for accepting newly proposed entities or sites as components of the IgG4-related disease spectrum
Genome editing using a DNA-free clustered regularly interspaced short palindromic repeats-Cas9 system in green seaweed Ulva prolifera
Although the green seaweed Ulva is one of the most common seaweeds in the coastal regions with well-studied ecological characteristics, few reverse genetic technologies have been developed for it. The clustered regularly interspaced short palindromic repeats (CRISPR)-Cas9 system is a simple genome-editing technology based on a ribonucleoprotein (RNP) complex composed of an endonuclease and programmable RNA to target particular DNA sequences. Genome editing makes it possible to generate mutations on a target gene in non-model organisms without established transgenic technologies. In this study, we applied the CRISPR-Cas9 RNP genome-editing system to the green seaweed Ulva prolifera, using polyethylene glycol (PEG)-mediated transfection. Our experimental system disrupts a single gene (UpAPT) encoding adenine phosphoribosyl transferase (APT) and generates a resistant phenotype for gametophytes cultured in a medium with toxic compound 2-fluoroadenine. The PEG-mediated transfection used for gametes resulted in 2-fluoroadenine-resistant strains containing short indels or substitutions on UpAPT. Our results showed that the CRISPR-Cas9 system with PEG-mediated transfection was efficient for genome editing in Ulva
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