Here we investigated mechanisms underlying the acclimation to light in the marine angiosperm Posidonia oceanica, along its bathymetric distribution (at −5 m and −25 m), combining molecular and ...photo-physiological approaches. Analyses were performed during two seasons, summer and autumn, in a meadow located in the Island of Ischia (Gulf of Naples, Italy), where a genetic distinction between plants growing above and below the summer thermocline was previously revealed. At molecular level, analyses carried out using cDNA-microarray and RT-qPCR, revealed the up-regulation of genes involved in photoacclimation (RuBisCO, ferredoxin, chlorophyll binding proteins), and photoprotection (antioxidant enzymes, xanthophyll-cycle related genes, tocopherol biosynthesis) in the upper stand of the meadow, indicating that shallow plants are under stressful light conditions. However, the lack of photo-damage, indicates the successful activation of defense mechanisms. This conclusion is also supported by several responses at physiological level as the lower antenna size, the higher number of reaction centers and the higher xanthophyll cycle pigment pool, which are common plant responses to high-light adaptation/acclimation.
Deep plants, despite the lower available light, seem to be not light-limited, thanks to some shade-adaptation strategies (e.g. higher antenna size, lower Ek values). Furthermore, also at the molecular level there were no signs of stress response, indicating that, although the lower energy available, low-light environments are more favorable for P. oceanica growth.
Globally, results of whole transcriptome analysis displayed two distinct gene expression signatures related to depth distribution, reflecting the different light-adaptation strategies adopted by P. oceanica along the depth gradient. This observation, also taking into account the genetic disjunction of clones along the bathymetry, might have important implications for micro-evolutionary processes happening at meadow scale. Further investigations in controlled conditions must be performed to respond to these questions.
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•Plants growing at different depths show characters of either sun- or shade-plants.•Photosynthetic efficiency is similar in low and high-light growing plants.•Light harvesting and photoprotective pigments are higher in shallower plants.•Photosynthesis is up-regulated in high light.•Distinct gene-expression signatures are related to depth distribution.
Submarine volcanic vents are being used as natural laboratories to assess the effects of increased ocean acidity and carbon dioxide (CO2) concentration on marine organisms and communities. However, ...in the vicinity of volcanic vents other factors in addition to CO2, which is the main gaseous component of the emissions, may directly or indirectly confound the biota responses to high CO2. Here we used for the first time the expression of antioxidant and stress-related genes of the seagrass Posidonia oceanica to assess the stress levels of the species. Our hypothesis is that unknown factors are causing metabolic stress that may confound the putative effects attributed to CO2 enrichment only. We analyzed the expression of 35 antioxidant and stress-related genes of P. oceanica in the vicinity of submerged volcanic vents located in the islands of Ischia and Panarea, Italy, and compared them with those from control sites away from the influence of vents. Reverse-transcription quantitative polymerase chain reaction (RT-qPCR) was used to characterize gene expression patterns. Fifty-one percent of genes analyzed showed significant expression changes. Metal detoxification genes were mostly down-regulated in relation to controls at both Ischia and Panarea, indicating that P. oceanica does not increase the synthesis of heavy metal detoxification proteins in response to the environmental conditions present at the two vents. The up-regulation of genes involved in the free radical detoxification response (e.g., CAPX, SODCP and GR) indicates that, in contrast with Ischia, P. oceanica at the Panarea site faces stressors that result in the production of reactive oxygen species, triggering antioxidant responses. In addition, heat shock proteins were also activated at Panarea and not at Ischia. These proteins are activated to adjust stress-accumulated misfolded proteins and prevent their aggregation as a response to some stressors, not necessarily high temperature. This is the first study analyzing the expression of target genes in marine plants living near natural CO2 vents. Our results call for contention to the general claim of seagrasses as "winners" in a high-CO2 world, based on observations near volcanic vents. Careful consideration of factors that are at play in natural vents sites other than CO2 and acidification is required. This study also constitutes a first step for using stress-related genes as indicators of environmental pressures in a changing ocean.
Posidonia oceanica is an endemic seagrass in the Mediterranean Sea, where it provides important ecosystem services and sustains a rich and diverse ecosystem. P. oceanica meadows extend from the ...surface to 40 meters depth. With the aim of boosting research in this iconic species, we generated a comprehensive RNA-Seq data set for P. oceanica by sequencing specimens collected at two depths and two times during the day. With this approach we attempted to capture the transcriptional diversity associated with change in light and other depth-related environmental factors. Using this extensive data set we generated gene predictions and identified an extensive catalogue of potential Simple Sequence Repeats (SSR) markers. The data generated here will open new avenues for the analysis of population genetic features and functional variation in P. oceanica. In total, 79,235 contigs were obtained by the assembly of 70,453,120 paired end reads. 43,711 contigs were successfully annotated. A total of 17,436 SSR were identified within 13,912 contigs.
As ecosystem engineers, seagrasses are angiosperms of paramount ecological importance in shallow shoreline habitats around the globe. Furthermore, the ancestors of independent seagrass lineages have ...secondarily returned into the sea in separate, independent evolutionary events. Thus, understanding the molecular adaptation of this clade not only makes significant contributions to the field of ecology, but also to principles of parallel evolution as well. With the use of Dr. Zompo, the first interactive seagrass sequence database presented here, new insights into the molecular adaptation of marine environments can be inferred. The database is based on a total of 14 597 ESTs obtained from two seagrass species, Zostera marina and Posidonia oceanica, which have been processed, assembled and comprehensively annotated. Dr. Zompo provides experimentalists with a broad foundation to build experiments and consider challenges associated with the investigation of this class of non-domesticated monocotyledon systems. Our database, based on the Ruby on Rails framework, is rich in features including the retrieval of experimentally determined heat-responsive transcripts, mining for molecular markers (SSRs and SNPs), and weighted key word searches that allow access to annotation gathered on several levels including Pfam domains, GeneOntology and KEGG pathways. Well established plant genome sites such as The Arabidopsis Information Resource (TAIR) and the Rice Genome Annotation Project are interfaced by Dr. Zompo. With this project, we have initialized a valuable resource for plant biologists in general and the seagrass community in particular. The database is expected to grow together with more data to come in the near future, particularly with the recent initiation of the Zostera genome sequencing project.The Dr. Zompo database is available at http://drzompo.uni-muenster.de/
Abstract Background Life expectancy after transplantation has improved, and cancer may soon be the leading cause of late death after transplantation. The guidelines of the American and European ...societies of nephrology and urology have not yet established the optimal frequency for screening for renal cell carcinoma (RCC) of native kidneys in patients who have undergone renal transplantation. Objective To evaluate the prevalence, prognosis, and risk factors of RCC in a series of patients followed up for 16 years in our transplantation unit. Materials and Methods Our study is a follow-up observational cohort study conducted in 694 consecutive renal transplant recipients admitted to our institution from July 1991 through July 2007. At our institution, ultrasound studies of the native kidneys were performed every 6 months after renal transplantation. Results In the patient cohort studied, 10 patients developed a renal tumor (1.6% incidence). Three patients died of causes other than recurrence of RCC. Seven patients are alive with no evidence of RCC recurrence or metastatic disease after a mean (range) follow-up of 41 (12–96) months. Acquired cystic kidney disease and dialysis duration were positively associated with development of RCC. Conclusions The incidence of RCC in the literature varies between 0.3% and 4.8%. The variability depends on the timing of follow-up, with a higher incidence in prospective studies with strict follow-up. We advise ultrasound studies performed by specialized physicians every 6 months after transplantation. More detailed guidelines designed by the major international transplantation societies are necessary.
Abstract No data are available on incisional hernia in renal transplant recipients using a midline incision. This study evaluated the incidence of abdominal wall incisional hernia, comparing two ...surgical approaches: midline and J-shaped incisions. Methods Between 1991 and 2005, 415 consecutive patients underwent renal transplantation: between 1991 and 1997, 139 patients through a lateral incision; between 1997 and 2005, 137 of 276 renal trasnsplant patients via a midline incision, and 139 via a J-shaped incision. We evaluated the incidence of incisional herniae in these patients. Analyzed factor risks included: age, sex, body mass index, diabetes, reoperation, lymphocele, dialysis time, underlying renal disease, and immunosuppressive therapy. Results During follow-up, 15 patients of 415 transplantations were dead or lost to follow-up. Incisional herniae were identified in 12 cases of 132 (9%) between 1991 and 1997. Between 1997 and 2005 we identified 3 of 133 (2.2%) patients who underwent a midline incision and 15 of 135 (11.1%) who received a J-shaped incision ( P = .005). Comparing midline and J-shaped incisions before and after 1997, the incidence reduction was significant ( P = .01). Comparing the incidence among patients treated with J-shaped incision before versus after 1997, the increased incidence was insignificant ( P = .6). Multivariate analysis found the most important risk factor was obesity followed by polycystic kidney disease, reoperation, wound infection, and mycophenolate mofetil therapy. Conclusions Our data showed an advantage of a midline incision. Strategies to prevent surgical complications, such as abdominal wall relaxation and poor cosmetic results, are needed; the midline incision may be a possible alternative to address this complication.
The incidence of urological complications after kidney transplantation varies from 3% to 14%, with a probable loss of the graft in 10% to 15% of cases and a mortality rate of up to 15%, despite ...improvements in prevention, diagnosis, and treatment as well as the use of new immunosuppressive therapies. Urinous fistulae, which are considered early complications of transplantation, are due to ischemic damage or necrosis generally occurring in the distal third of the ureter. Preservation of accessory arteries to the lower portion of the kidney is important, as they may constitute the blood supply of this segment of the collecting system or ureter. Their ligation may lead to necrosis and urinary fistulae. Ureteral stenosis, as late complication, is related to a pathology of the ureter itself, to infections, to abscesses, to fibrosis, and to ischemia. An early endoscopic approach permits resolution in 70% of cases. The aim of this retrospective study was to determine incidence and treatment of these complications.
From 1991 to 2004 we performed 453 kidney transplantations both from cadaveric and living donors. In 199 patients we performed a transvesical ureteroneocystostomy (UNCS), and in 260, an extravesical UNCS.
The nine patients who showed fistulae (1.9%) underwent surgical treatment. In eight we used a direct ureteral reimplantation, and in one, a Boari flap technique. Nephrectomy was necessary in four patients, including two who died of septic complications. In all 26 cases of ureteral stenosis (5.6%), we used an endourological approach (anterograde or retrograde), with surgical treatment afterward in 11 patients (42%) nine direct reimplants, one anastomosis to the native ureter (transplantation from a living donor), and in one case a Boari flap technique four patients who underwent surgical treatment showed progressive damage to graft function.
In all patients who showed fistulae we suggest surgical review: for patients with ureteral stenosis, we suggest first an endourological approach and only when it is not successful do we consider surgical treatment.
The LMJ experimental plans include the attempt of ignition and burn of an ICF capsule with 40 laser quads, delivering up to 1.4MJ and 380TW. New targets needing reduced laser energy with only a small ...decrease in robustness are then designed for this purpose. A first strategy is to use scaled-down cylindrical hohlraums and capsules, taking advantage of our better understanding of the problem, set on theoretical modelling, simulations and experiments. Another strategy is to work specifically on the coupling efficiency parameter, i.e. the ratio of the energy absorbed by the capsule to the laser energy, which is with parametric instabilities a crucial drawback of indirect drive. An alternative design is proposed, made up of the nominal 60 quads capsule, named A1040, in a rugby-shaped hohlraum. Robustness evaluations of these different targets are in progress.
Scientific Data 3:160115 doi: 10.1038/sdata.2016.115 (2016); Published 20 December 2016; Updated 14 March 2017 The original version of this Data Descriptor contained a typographical error in the ...spelling of the author A. Lamontanara, which was incorrectly given as A. Lamontara. This has now been corrected in the PDF and HTML versions of the Data Descriptor.
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