Preliminary Studies on the Photosynthetic Structures of Trifolium alpinum L. as Related to Productivity

Trifolium alpinum L. is a high-quality alpine forage plant growingspontaneously from 1900 to 2800 m above sea level and is widelydistributed in Piedmont and the Valle d'Aosta (Italy), whereit can reach population frequencies of 90 per cent. Yields weredetermined on forage harvested in the Valle dell'Orco (Piedmont)and were comparable to cultivated clovers from higher latitudes;yields decreased progressively as the elevation increased. Thechemical and nutritional characteristics of the forage, thoughcomparable to clovers cultivated in the Po valley (Italy), were,however, more constant. The structure of the leaf lamina asrelated to elevation was investigated using light microscopy,TEM and SEM. This is complemented by data on chlorophyll concentration,succulence, specific leaf weight and area. At all elevationsT. alpinum lacks, apart from bundle sheath cell chloroplastsin a centrifugal arrangement, the structural characteristicsof C₄ plants. The chlorophyll a:b ratio (less than four) istypical of a C₂ plant. Succulence indices (S and S_m) were verylow, making CAM pathway photosynthesis unlikely. Unusual anddifficult to interpret structures included: small functionalchloroplasts in both the epidermises, stomata present almostexclusively in the upper epidermis and mitochondria enveloped(or enclosed) by chloroplasts. It was observed that, as theelevation increases, populations are selected which are well-adaptedfor gas exchange (increase in specific leaf area, stomatal densityand intercellular spaces) and characterized by a decrease inthe grana thylacoid:integrana thylacoid ratio (consistent withthe increase in the chlorophyll a:b ratio), the per cent water,S_m and the specific leaf weight. Trifolium alpinum L., alpine trefoil, leaf structures, photosynthesis, yield, elevation, C₂, C₄     

Tolerance to the fungal pathogen Rhizoctonia solani AG4 of transgenic tobacco expressing the maize ribosome-inactivating protein b-32

The maize b-32 protein is a functional ribosome-inactivating protein (RIP), inhibiting in vitro translation in the cell-free reticulocyte-derived system and having specific N-glycosidase activity on 28S rRNA. Previous results indicated that opaque-2 (o2) mutant kernels, lacking b-32, show an increased susceptibility to fungal attack and insect feeding and that ectopic expression in plants of a barley and a pokeweed RIP leads to increased tolerance to fungal and viral infection. This prompted us to test whether b-32 might functi on as a protectant against pathogens. The b32.66 cDNA clone under the control of the potato wun1 gene promoter was introduced into tobacco by Agrobacterium tumefaciens-mediated transformation. Out of 23 kanamycin resistant regenerated shoots, 16 contained a PCR fragment of the corrrect size spanning the boundary between the promoter used and the coding region of the b-32 gene. Eight independently transformed tobacco lines were randomly chosen for protein analysis: all of them expressed b-32 protein. The data presented indicate that transgenic tobacco plants expressing b-32 show an increased tolerance against infection by the soil-borne fungal pathogen Rhizoctonia solani Kuhn     

Taxonomic relationships between Pachycerus and Rhabdorrhynchus (Coleoptera: Curculionidae: Lixinae), with descriptions of two new species of Rhabdorrhynchus from the Arabian Peninsula

Taxonomic relationships between Rhabdorrhynchus and Pachycerus are discussed, and two new species of Rhabdorrhynchus are described: Rhabdorrhynchus sauditus (type locality: Saudi Arabia, As Shāqqah al Yamānīyah, 19°42'N, 40°48'E) and Rhabdorrhynchus emir (type locality: United Arab Emirates, Jebel Ali, 24°59'N, 55°43'E). Some hypotheses on the distribution of the new species in the Arabian Peninsula, based on a biogeographical analysis, are proposed.  © 2008 The Linnean Society of London, Zoological Journal of the Linnean Society , 2008, 152 , 25–37.     

Karyotype morphology and cytogeography in Brunnera and Cynoglottis (Boraginaceae)

A comparative study of karyotype morphology and heterochromatin patterns in Brunnera and Cynoglottis (Boraginaceae) was carried out with traditional methods and Giemsa C-banding. Two polymorphic species of Cynoglottis , each with two subspecies, and two of Brunnera were investigated using native population samples from the central-eastern Mediterranean and Middle East. Pollen size of these samples was measured to investigate relationships with ploidy level. C. barrelieri subsp. barrelieri and subsp. serpentinicola are characterized by In = 18 and smaller pollen grains in contrast to C. chetikiana subsp. chetikiana and subsp. paphlagonica , which are fundamentally tetraploid with 2n = 36. The occurrence of cytotypes with 2n –/2 and 2n = 24 in both subspecies of C. chetikiana , however, would suggest x = 6 as the original haploid number and x = 9 as a derived one. Furthermore, the finding of a hypoploid cytotype with 2n = 16 in C. barrelieri ssp. barrelieri was consistent with previous reports and suggested relationships with Anchusa. Karyoevolutionary processes possibly associated with such a wide chromosome variation in Cynoglottis are discussed. Brunnera macrophylla and B. orientalis share a complement of 2n= 12 and an apparently identical karyotype, which differs from Cynoglottis in terms of asymmetry, chromosome size and morphology. A basic C-banding style was present in Brunnera and Cynoglottis , but heterochromatin content increased from the former to the latter. The parallel increase in chromosome number, heterochromatin content and size of the pollen from Brunnera to Cynoglottis may reflect an evolutionary progression, and is consistent with the supposed ancient origin of Brunnera.     

In vitro and in vivo discrepancy in inducing apoptosis by mesenchymal stromal cells delivering membrane-bound tumor necrosis factor–related apoptosis inducing ligand in osteosarcoma pre-clinical models

Background

Osteosarcoma (OS) is the most frequent pediatric malignant bone tumor. OS patients have not seen any major therapeutic progress in the last 30 years, in particular in the case of metastatic disease, which requires new therapeutic strategies. The pro-apoptotic cytokine Tumor necrosis factor (TNF)–Related Apoptosis Inducing Ligand (TRAIL) can selectively kill tumor cells while sparing normal cells, making it a promising therapeutic tool in several types of cancer. However, many OS cell lines appear resistant to recombinant human (rh)TRAIL-induced apoptosis. We, therefore, hypothesized that TRAIL presentation at the membrane level of carrier cells might overcome this resistance and trigger apoptosis.

Evidence of Actin in the Cytoskeleton of Microsporidia

Using transmission electron microscopy, immuno-electron microscopy, and biochemical techniques such as 2-D electrophoresis and immunoblotting, actin was found in all biological stages of the microsporidia Encephalitozoon hellem and Encephalitozoon cuniculi.     

Proceedings of the signature series symposium “cellular therapies for orthopaedics and musculoskeletal disease proven and unproven therapies—promise,facts and fantasy,” international society for cellular therapies,montreal, canada,may 2, 2018

The Signature Series Symposium “Cellular Therapies for Orthopaedics and Musculoskeletal Disease Proven and Unproven Therapies—Promise, Facts and Fantasy” was held as a pre-meeting of the 26^th International Society for Cellular Therapy (ISCT) annual congress in Montreal, Canada, May 2, 2018. This was the first ISCT program that was entirely dedicated to the advancement of cell-based therapies for musculoskeletal diseases. Cellular therapies in musculoskeletal medicine are a source of great promise and opportunity. They are also the source of public controversy, confusion and misinformation. Patients, clinicians, scientists, industry and government share a commitment to clear communication and responsible development of the field. Therefore, this symposium convened thought leaders from around the world in a forum designed to catalyze communication and collaboration to bring the greatest possible innovation and value to patients with musculoskeletal conditions.     

Eutrophication and macroalgal blooms in temperate and tropical coastal waters: nutrient enrichment experiments with Ulva spp.

Receiving coastal waters and estuaries are among the most nutrient‐enriched environments on earth, and one of the symptoms of the resulting eutrophication is the proliferation of opportunistic, fast‐growing marine seaweeds. Here, we used a widespread macroalga often involved in blooms, Ulva spp., to investigate how supply of nitrogen (N) and phosphorus (P), the two main potential growth‐limiting nutrients, influence macroalgal growth in temperate and tropical coastal waters ranging from low‐ to high‐nutrient supplies. We carried out N and P enrichment field experiments on Ulva spp. in seven coastal systems, with one of these systems represented by three different subestuaries, for a total of nine sites. We showed that rate of growth of Ulva spp. was directly correlated to annual dissolved inorganic nitrogen (DIN) concentrations, where growth increased with increasing DIN concentration. Internal N pools of macroalgal fronds were also linked to increased DIN supply, and algal growth rates were tightly coupled to these internal N pools. The increases in DIN appeared to be related to greater inputs of wastewater to these coastal waters as indicated by high δ¹⁵N signatures of the algae as DIN increased. N and P enrichment experiments showed that rate of macroalgal growth was controlled by supply of DIN where ambient DIN concentrations were low, and by P where DIN concentrations were higher, regardless of latitude or geographic setting. These results suggest that understanding the basis for macroalgal blooms, and management of these harmful phenomena, will require information as to nutrient sources, and actions to reduce supply of N and P in coastal waters concerned.     

Genetic variation and differentiation in the lizard, Podarcis wagleriana (Reptilia: Lacertidae)

The electrophoretic variation at 26 presumptive gene loci was investigated in populations of Podarcis ivagleriana from Sicily, the Aegadian Islands, and the Aeolian Islands. For interspecific comparison, samples of the closely related lizard P. sicula from the same geographic area were also used. Population heterogeneity analyses carried out by the estimation of F-statistics and Nei's standard genetic distance, showed a high genetic homogeneity within P. sicula, but a noticeable genetic differentiation within P. wagleriana. In the latter species, Nei's D ranged from 0 to 0.212, and this is because the Aeolian populations were quite distinct from those inhabiting Sicily and the Aegadian Islands. Fixed differences identified at three loci (Ck, Ada, Gp-4) contributed to a relatively high value of Nei's standard genetic distance between the two population groups (D= 0.147). This value is very similar to those found comparing pairs of well-recognized biological species included in the genera Podarcis and Lacerta. Estimation of the time of evolutionary divergence shows that the Aeolian and Sicilian populations of P. wagleriana have been isolated geographically for a long time (0.7 Myr according to Nei's formula; 2 Myr according to Sarich's calibration), indicating evolutionary divergence at the species level. Based on genetic and biogeographic data, it is suggested the recognition of full specific status for the Aeolian populations, for which the name P. rajfonei comb. nova (Aeolian wall lizard) is proposed. Electrophoretic data and comparative species distributions suggest that (1) Podarcis sicula recently colonized the Aeolian Islands, and (2) it has competed successfully with P. rajfonei in this area, greatly reducing the range of the latter and causing the extinction of most of its populations. In fact, P. sicula is widespread in the Aeolian Archipelago, while P. rajfonei is confined at present to one large island (Vulcano) and three tiny islands (Strombolicchio, Scoglio Faraglione, La Canna). This can be considered a classic example of competitive exclusion of a native form (P. rajfonei) by a species accidentally introduced by man (P. sicula).