Transcriptome characterisation and simple sequence repeat marker discovery in the seagrass Posidonia oceanica

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.

Response of the seagrass Posidonia oceanica to different light environments: Insights from a combined molecular and photo-physiological study

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.

Dr. Zompo: an online data repository for Zostera marina and Posidonia oceanica ESTs

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/

The Treatment of Fistulae and Ureteral Stenosis After Kidney Transplantation

INTRODUCTION

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.

MATERIALS AND METHODS

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.

RESULTS

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.

CONCLUSIONS

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.

[Early antibiotic therapy following urodynamic examination. Results of a randomized, controlled study]

Forty-three young men from the Italian army underwent urodynamic tests following the diagnosis of enuresis. Of these, 37 were included in an assessment trial to define the rationale for early anti-bacterial therapy following the test. The subjects were subdivided into two groups: one group received 500 mg Cinoxacin b.i.d. for 5 days, and the other group was not treated. The comparison of results revealed a high incidence of irritative disorders in both groups (78.9% of treated subjects and 88.9% of untreated subjects) but the most significant complications were observed in the untreated group (feveret in 27.7% and one case of septic fever). Early anti-bacterial therapy following standard urodynamic tests therefore seems to be a ration tool in urological practice.