Evidence for a Common Toolbox Based on Necrotrophy in a Fungal Lineage Spanning Necrotrophs, Biotrophs, Endophytes, Host Generalists and Specialists

The Sclerotiniaceae (Ascomycotina, Leotiomycetes) is a relatively recently evolved lineage of necrotrophic host generalists, and necrotrophic or biotrophic host specialists, some latent or symptomless. We hypothesized that they inherited a basic toolbox of genes for plant symbiosis from their common ancestor. Maintenance and evolutionary diversification of symbiosis could require selection on toolbox genes or on timing and magnitude of gene expression. The genes studied were chosen because their products have been previously investigated as pathogenicity factors in the Sclerotiniaceae. They encode proteins associated with cell wall degradation: acid protease 1 (acp1), aspartyl protease (asps), and polygalacturonases (pg1, pg3, pg5, pg6), and the oxalic acid (OA) pathway: a zinc finger transcription factor (pac1), and oxaloacetate acetylhydrolase (oah), catalyst in OA production, essential for full symptom production in Sclerotinia sclerotiorum. Site-specific likelihood analyses provided evidence for purifying selection in all 8 pathogenicity-related genes. Consistent with an evolutionary arms race model, positive selection was detected in 5 of 8 genes. Only generalists produced large, proliferating disease lesions on excised Arabidopsis thaliana leaves and oxalic acid by 72 hours in vitro. In planta expression of oah was 10–300 times greater among the necrotrophic host generalists than necrotrophic and biotrophic host specialists; pac1 was not differentially expressed. Ability to amplify 6/8 pathogenicity related genes and produce oxalic acid in all genera are consistent with the common toolbox hypothesis for this gene sample. That our data did not distinguish biotrophs from necrotrophs is consistent with 1) a common toolbox based on necrotrophy and 2) the most conservative interpretation of the 3-locus housekeeping gene phylogeny – a baseline of necrotrophy from which forms of biotrophy emerged at least twice. Early oah overexpression likely expands the host range of necrotrophic generalists in the Sclerotiniaceae, while specialists and biotrophs deploy oah, or other as-yet-unknown toolbox genes, differently

Evaluation of lymphatic compensation by lymphoscintigraphy in the postoperative period of breast cancer surgery with axillary dissection

Objective. To evaluate postoperative lymphatic compensation in the upper limb after mastectomy with axillary dissection. Subjects and methods. Twenty-three patients who underwent lymphoscintigraphy before and 60 days after surgery were enrolled from September 2006 to June 2007, in Campinas, Brazil. Protocol examination consisted in static imaging of each upper limb in semi-flexion and thoracic imaging after 10 min and 1 and 2 hr after subcutaneous injection of 1 mCi (37 MBq) of (99m)Tc dextran into the dorsum of the hand. A comparative analysis was made of hepatic uptake of the radiopharmaceutical, velocity of axillary lymph node visualization (I, visible at 10 min; II, at 1 hr; III, at 2 hr; IV, not visible) and degree (intensity) of uptake (a, marked; b, moderate; c, mild; d, absent) before and 60 days after surgery. Results. In the preoperative period, 3 (13%) patients were considered to have an optimal pattern (Ia) and 2 (9%) showed total involvement (IVd). Compared to velocity in the postoperative period, 9 (39%) patients showed no difference, 5 (22%) improved, 9 (39%) became worse, and one was considerably worse. Regarding the degree, 10 (43%) patients showed no difference, 9 (39%) became worse, and 4 (17%) improved. Regarding classification, 2 (9%) patients had an optimal lymphatic pattern (Ia) and 3 (13%) had total involvement (IVd). No patient presented decreased hepatic uptake after surgical treatment. Conclusions. The study found relevant changes in preoperative and postoperative lymphoscintigraphy, demonstrating the existence of functional differences in the lymphatic system of the upper limb. Alterations in lymphatic drainage pattern may already be perceived 60 days postoperatively, as can signs of lymphovenous anastomoses.97330931