Patients with AIP are at high risk of having various cancers. The highest risk for cancer in the first year after AIP diagnosis and absence of AIP relapse after successful treatment of the coexisting cancers suggest that AIP may develop as a paraneoplastic syndrome in some patients.
By preventing tumor ingrowth and migration, covered SEMSs with an anti-migration system had a longer duration of patency than uncovered SEMSs, which recommends their use in the palliative treatment of patients with biliary obstruction due to pancreatic carcinomas.
Plants are constantly exposed to threats from pathogenic microbes and thus developed an innate immune system to protect themselves. On the other hand, many plants also have the ability to establish endosymbiosis with beneficial microbes such as arbuscular mycorrhizal (AM) fungi or rhizobial bacteria, which improves the growth of host plants. How plants evolved these systems managing such opposite plant-microbe interactions is unclear. We show here that knockout (KO) mutants of OsCERK1, a rice receptor kinase essential for chitin signaling, were impaired not only for chitin-triggered defense responses but also for AM symbiosis, indicating the bifunctionality of OsCERK1 in defense and symbiosis. On the other hand, a KO mutant of OsCEBiP, which forms a receptor complex with OsCERK1 and is essential for chitin-triggered immunity, established mycorrhizal symbiosis normally. Therefore, OsCERK1 but not chitin-triggered immunity is required for AM symbiosis. Furthermore, experiments with chimeric receptors showed that the kinase domains of OsCERK1 and homologs from non-leguminous, mycorrhizal plants could trigger nodulation signaling in legume-rhizobium interactions as the kinase domain of Nod factor receptor1 (NFR1), which is essential for triggering the nodulation program in leguminous plants, did. Because leguminous plants are believed to have developed the rhizobial symbiosis on the basis of AM symbiosis, our results suggest that the symbiotic function of ancestral CERK1 in AM symbiosis enabled the molecular evolution to leguminous NFR1 and resulted in the establishment of legume-rhizobia symbiosis. These results also suggest that OsCERK1 and homologs serve as a molecular switch that activates defense or symbiotic responses depending on the infecting microbes.
The tomato is an excellent model for studies of plants bearing berry-type fruits and for experimental studies of the Solanaceae family of plants due to its conserved genetic organization. In this study, a comprehensive mutant tomato population was generated in the background of Micro-Tom, a dwarf, rapid-growth variety. In this and previous studies, a family including 8,598 and 6,422 M2 mutagenized lines was produced by ethylmethane sulfonate (EMS) mutagenesis and γ-ray irradiation, and this study developed and investigated these M2 plants for alteration of visible phenotypes. A total of 9,183 independent M2 families comprising 91,830 M2 plants were inspected for phenotypic alteration, and 1,048 individual mutants were isolated. Subsequently, the observed mutant phenotypes were classified into 15 major categories and 48 subcategories. Overall, 1,819 phenotypic categories were found in 1,048 mutants. Of these mutants, 549 were pleiotropic, whereas 499 were non-pleiotropic. Multiple different mutant alleles per locus were found in the mutant libraries, suggesting that the mutagenized populations were nearly saturated. Additionally, genetic analysis of backcrosses indicated the successful inheritance of the mutations in BC1F2 populations, confirming the reproducibility in the morphological phenotyping of the M2 plants. To integrate and manage the visible phenotypes of mutants and other associated data, we developed the in silico database TOMATOMA, a relational system interfacing modules between mutant line names and phenotypic categories. TOMATOMA is a freely accessible database, and these mutant recourses are available through the TOMATOMA (http://tomatoma.nbrp.jp/index.jsp).
To accelerate functional genomic research in tomato, we developed a Micro-Tom TILLING (Targeting Induced Local Lesions In Genomes) platform. DNA pools were constructed from 3,052 ethyl methanesulfonate (EMS) mutant lines treated with 0.5 or 1.0% EMS. The mutation frequency was calculated by screening 10 genes. The 0.5% EMS population had a mild mutation frequency of one mutation per 1,710 kb, whereas the 1.0% EMS population had a frequency of one mutation per 737 kb, a frequency suitable for producing an allelic series of mutations in the target genes. The overall mutation frequency was one mutation per 1,237 kb, which affected an average of three alleles per kilobase screened. To assess whether a Micro-Tom TILLING platform could be used for efficient mutant isolation, six ethylene receptor genes in tomato (SlETR1–SlETR6) were screened. Two allelic mutants of SlETR1 (Sletr1-1 and Sletr1-2) that resulted in reduced ethylene responses were identified, indicating that our Micro-Tom TILLING platform provides a powerful tool for the rapid detection of mutations in an EMS mutant library. This work provides a practical and publicly accessible tool for the study of fruit biology and for obtaining novel genetic material that can be used to improve important agronomic traits in tomato.
SUMMARYXanthophylls, the pigments responsible for yellow to red coloration, are naturally occurring carotenoid compounds in many colored tissues of plants. These pigments are esterified within the chromoplast; however, little is known about the mechanisms underlying their accumulation in flower organs. In this study, we characterized two allelic tomato (Solanum lycopersicum L.) mutants, pale yellow petal (pyp) 1-1 and pyp1-2, that have reduced yellow color intensity in the petals and anthers due to loss-of-function mutations. Carotenoid analyses showed that the yellow flower organs of wild-type tomato contained high levels of xanthophylls that largely consisted of neoxanthin and violaxanthin esterified with myristic and/or palmitic acids. Functional disruption of PYP1 resulted in loss of xanthophyll esters, which was associated with a reduction in the total carotenoid content and disruption of normal chromoplast development. These findings suggest that xanthophyll esterification promotes the sequestration of carotenoids in the chromoplast and that accumulation of these esters is important for normal chromoplast development. Next-generation sequencing coupled with map-based positional cloning identified the mutant alleles responsible for the pyp1 phenotype. PYP1 most likely encodes a carotenoid modifying protein that plays a vital role in the production of xanthophyll esters in tomato anthers and petals. Our results provide insight into the molecular mechanism underlying the production of xanthophyll esters in higher plants, thereby shedding light on a longstanding mystery.
SUMMARYFruit set in angiosperms marks the transition from flowering to fruit production and a commitment to seed dispersal. Studies with Solanum lycopersicum (tomato) fruit have shown that pollination and subsequent fertilization induce the biosynthesis of several hormones, including auxin and gibberellins (GAs), which stimulate fruit set. Circumstantial evidence suggests that the gaseous hormone ethylene may also influence fruit set, but this has yet to be substantiated with molecular or mechanistic data. Here, we examined fruit set at the biochemical and genetic levels, using hormone and inhibitor treatments, and mutants that affect auxin or ethylene signaling. The expression of system-1 ethylene biosynthetic genes and the production of ethylene decreased during pollination-dependent fruit set in wild-type tomato and during pollination-independent fruit set in the auxin hypersensitive mutant iaa9-3. Blocking ethylene perception in emasculated flowers, using either the ethylene-insensitive Sletr1-1 mutation or 1-methylcyclopropene (1-MCP), resulted in elongated parthenocarpic fruit and increased cell expansion, whereas simultaneous treatment with the GA biosynthesis inhibitor paclobutrazol (PAC) inhibited parthenocarpy. Additionally, the application of the ethylene precursor 1-aminocyclopropane-1-carboxylic acid (ACC) to pollinated ovaries reduced fruit set. Furthermore, Sletr1-1 parthenocarpic fruits did not exhibit increased auxin accumulation, but rather had elevated levels of bioactive GAs, most likely reflecting an increase in transcripts encoding the GA-biosynthetic enzyme SlGA20ox3, as well as a reduction in the levels of transcripts encoding the GA-inactivating enzymes SlGA2ox4 and SlGA2ox5. Taken together, our results suggest that ethylene plays a role in tomato fruit set by suppressing GA metabolism.
Objective: To evaluate the diagnostic accuracy of liver cirrhosis by imaging modalities, including CT, MRI and US, compared to results obtained from histopathological diagnoses of resected specimens. Materials and Methods: CT, MRI and US examinations of 142 patients with chronic liver disease who underwent surgery for complicated hepatocellular carcinoma (<3 cm in diameter) in 10 institutions were blindly reviewed in a multicenter study by three radiologists experienced in CT, MRI and US. The images were evaluated for five imaging parameters (irregular or nodular liver surface, blunt liver edge, liver parenchymal abnormalities, liver morphological changes and manifestations of portal hypertension) using a severity scale. The diagnostic imaging impression score was also calculated. Patients were histologically classified into chronic hepatitis (CH; n = 54), liver cirrhosis (LC; n = 71) and pre-cirrhosis (P-LC; n = 17) by three pathologists, independently, who reviewed the resected liver specimens. The results of the three imaging methods were compared to those from histological diagnoses, and a multivariate analysis (stepwise forward logistic regression analysis) was performed to identify independent predictive signs of cirrhosis. The diagnostic efficacies for LC and early cirrhosis were also compared among CT, MRI and US using a receiver-operating characteristic (ROC) curve analysis. Results: The differences in the five imaging parameters evaluated by CT, MRI and US between LC and CH were statistically significant (p < 0.001) except for the manifestations of portal hypertension on US. Irregular or nodular surface, blunt edge or morphological changes in the liver were selected as the best predictive signs for cirrhosis on US whereas liver parenchymal abnormalities, manifestations of portal hypertension and morphological changes in the liver were the best predictive signs on MRI and CT by multivariate analysis. The predictive diagnostic accuracy, sensitivity and specificity in discriminating LC from CH based on the best predictive signs were 71.9, 77.1 and 67.6% by CT; 67.9, 67.5 and 68.3% by MRI, and 66.0, 38.4 (lower than CT and MRI, p =0.001) and 88.8% (higher than CT and MRI, p =0.001)by US. According to the imaging impression scoring system, diagnostic accuracy, sensitivity and specificity were 67.0, 84.3 and 52.9% by CT; 70.3, 86.7 and 53.9% by MRI, and 64.0, 52.4 (lower than CT and MRI, p =0.0001) and 73.5% (higher than CT and MRI, p < 0.003) by US. ROC analysis showed that MRI and CT were slightly superior to US in the diagnosis of LC but no statistically significant difference was found between them. For the pathological diagnosis of P-LC, cirrhosis was diagnosed in 59.5, 46.7 and 41.7% of the P-LC cases by US, CT and MRI, respectively, with no significant difference among these methods. Conclusion: US, CT and MRI had different independent predictive signs for the diagnosis of LC. MRI and CT were slightly superior to US in predicting cirrhosis, especially regarding sensitivity. Noninvasive imaging techniqu...
scite is a Brooklyn-based organization that helps researchers better discover and understand research articles through Smart Citations–citations that display the context of the citation and describe whether the article provides supporting or contrasting evidence. scite is used by students and researchers from around the world and is funded in part by the National Science Foundation and the National Institute on Drug Abuse of the National Institutes of Health.
hi@scite.ai
10624 S. Eastern Ave., Ste. A-614
Henderson, NV 89052, USA
Copyright © 2024 scite LLC. All rights reserved.
Made with 💙 for researchers
Part of the Research Solutions Family.