Railway Embankments as New Habitat for Pollinators in an Agricultural Landscape

Pollinating insect populations, essential for maintaining wild plant diversity and agricultural productivity, rely on (semi)natural habitats. An increasing human population is encroaching upon and deteriorating pollinator habitats. Thus the population persistence of pollinating insects and their associated ecosystem services may depend upon on man-made novel habitats; however, their importance for ecosystem services is barely understood. We tested if man-made infrastructure (railway embankments) in an agricultural landscape establishes novel habitats that support large populations of pollinators (bees, butterflies, hoverflies) when compared to typical habitats for these insects, i.e., semi-natural grasslands. We also identified key environmental factors affecting the species richness and abundance of pollinators on embankments. Species richness and abundance of bees and butterflies were higher for railway embankments than for grasslands. The occurrence of bare (non-vegetated) ground on embankments positively affected bee species richness and abundance, but negatively affected butterfly populations. Species richness and abundance of butterflies positively depended on species richness of native plants on embankments, whereas bee species richness was positively affected by species richness of non-native flowering plants. The density of shrubs on embankments negatively affected the number of bee species and their abundance. Bee and hoverfly species richness were positively related to wood cover in a landscape surrounding embankments. This is the first study showing that railway embankments constitute valuable habitat for the conservation of pollinators in farmland. Specific conservation strategies involving embankments should focus on preventing habitat deterioration due to encroachment of dense shrubs and maintaining grassland vegetation with patches of bare ground.     

Arene- and quinoline-sulfonamides as novel 5-HT7 receptor ligands

Novel arene- and quinolinesulfonamides were synthesized using different solutions and a solid-support methodology, and were evaluated for their affinity for 5-HT(1A), 5-HT(2A), 5-HT(6), and 5-HT(7) receptors. Compound 54 (N-Ethyl-N-[4-(1,2,3,4,4a,5,6,7,8,8a-decahydroisoquinolin-2-yl)butyl]-8-quinolinesulfonamide) was identified as potent 5-HT(7) antagonist (K(i)=13 nM, K(B)=140 nM) with good selectivity over 5-HT(1A), 5-HT(2A), 5-HT(6) receptors. In the FST in mice, it reduced immobility in a manner similar to the selective 5-HT(7) antagonist SB-269970.     

The effect of luminal ghrelin on pancreatic enzyme secretion in the rat

Ghrelin, a 28-amino-acid peptide produced predominantly by oxyntic mucosa has been reported to affect the pancreatic exocrine function but the mechanism of its secretory action is not clear. The effects of intraduodenal (i.d.) infusion of ghrelin on pancreatic amylase outputs under basal conditions and following the stimulation of pancreatic secretion with diversion of pancreato-biliary juice (DPBJ) as well as the role of vagal nerve, sensory fibers and CCK in this process were determined. Ghrelin given into the duodenum of healthy rats at doses of 1.0 or 10.0 microg/kg increased pancreatic amylase outputs under basal conditions or following the stimulation of pancreatic secretion with DPBJ. Bilateral vagotomy as well as capsaicin deactivation of sensory fibers completely abolished all stimulatory effects of luminal ghrelin on pancreatic exocrine function. Pretreatment with lorglumide, a CCK(1) receptor blocker, reversed the stimulation of amylase release produced by intraduodenal application of ghrelin. Intraduodenal ghrelin at doses of 1.0 or 10.0 microg/kg increased plasma concentrations of CCK and ghrelin. In conclusion, ghrelin given into the duodenum stimulates pancreatic enzyme secretion. Activation of vagal reflexes and CCK release as well as central mechanisms could be implicated in the stimulatory effect of luminal ghrelin on the pancreatic exocrine functions.     

Spinophilin facilitates dephosphorylation of doublecortin by PP1 to mediate microtubule bundling at the axonal wrist

The axonal shafts of neurons contain bundled microtubules, whereas extending growth cones contain unbundled microtubule filaments, suggesting that localized activation of microtubule-associated proteins (MAP) at the transition zone may bundle these filaments during axonal growth. Dephosphorylation is thought to lead to MAP activation, but specific molecular pathways have remained elusive. We find that Spinophilin, a Protein-phosphatase 1 (PP1) targeting protein, is responsible for the dephosphorylation of the MAP Doublecortin (Dcx) Ser 297 selectively at the "wrist" of growing axons, leading to activation. Loss of activity at the "wrist" is evident as an impaired microtubule cytoskeleton along the shaft. These findings suggest that spatially restricted adaptor-specific MAP reactivation through dephosphorylation is important in organization of the neuronal cytoskeleton.     

Expression of the RAI gene is conducive to apoptosis: studies of induction and interference

The RAI gene is also known as iASPP and PPP1R13L. Recent investigations have shown that the region encompassing RAI is important for the development of cancer in young and middle-aged persons. It has been speculated that the RAI product induces apoptosis by blocking NF-kappaB or inhibits apoptosis by blocking p53. Either way the gene could influence the survival of precancerous lesions. Here we report that the expression of RAI mRNA was increased in non-transformed lymphocytes and fibroblasts induced to undergo apoptosis by various means, such as treatment with etoposide, calcium ions, or interleukin-2 and/or serum deprivation. Treatment with etoposide increased the content of RAI protein, too, and caused it to translocate to the nucleus. Inhibition of RAI expression in lymphocytes and fibroblasts with siRNA reduced apoptosis, but treatment with the NF-kappaB-inhibiting substance sulfasalazine relieved this dependence. In the transformed cell line HEK-293 the association between RAI induction and apoptosis seemed broken. Thus, we hypothesize that RAI induction is necessary but not sufficient for apoptosis induction in non-transformed cells. Our results could be explained by a NF-kappaB mediated mechanism.     

The etiology of multiple sclerosis: genetic evidence for the involvement of the human endogenous retrovirus HERV-Fc1

We have investigated the role of human endogenous retroviruses in multiple sclerosis by analyzing the DNA of patients and controls in 4 cohorts for associations between multiple sclerosis and polymorphisms near viral restriction genes or near endogenous retroviral loci with one or more intact or almost-intact genes. We found that SNPs in the gene TRIM5 were inversely correlated with disease. Conversely, SNPs around one retroviral locus, HERV-Fc1, showed a highly significant association with disease. The latter association was limited to a narrow region that contains no other known genes. We conclude that HERV-Fc1 and TRIM5 play a role in the etiology of multiple sclerosis. If these results are confirmed, they point to new modes of treatment for multiple sclerosis.     

Identification of Treponema denticola in subgingival samples by PCR technology and its correlation with clinical diagnosis

Treponema denticola has been associated with gingivitis and chronic periodontitis. The aim of this study was to identify Treponema denticola in subgingival samples using PCR technology and to correlate it with clinical diagnosis of subjects. The study was carried out on seventy patients (20-84 years of age; mean age, 45.06 +/- 12.58) of which 22 individuals with no detectable gingivitis or periodontitis, 4 subjects with chronic gingivitis and 44 subjects with chronic periodontitis. Subgingival plaque samples were collected from five sites in each patient. DNA was extracted from the samples using QIAamp DNA Mini Kit (QIAGEN). Treponema denticola and other four periodontopathogens were found using multiplex polymerase chain reaction followed by a reverse hybridization. The relationship between clinical diagnoses and detection of Treponema denticola was determined with Fisher exact test. The results showed significant differences between diagnostic groups regarding subject proportion. Treponema denticola was detected in 2 out of 22 subjects with no detectable gingivitis or periodontitis, 2 out of 4 subjects with chronic gingivitis, and 40 out of 44 subjects with chronic periodontitis. Our findings suggest that Treponema denticola is closely connected to the initiation and progression of periodontal disease.     

Genetic dissection of vitamin E biosynthesis in tomato

Vegetables are critical for human health as they are a source of multiple vitamins including vitamin E (VTE). In plants, the synthesis of VTE compounds, tocopherol and tocotrienol, derives from precursors of the shikimate and methylerythritol phosphate pathways. Quantitative trait loci (QTL) for α-tocopherol content in ripe fruit have previously been determined in an Solanum pennellii tomato introgression line population. In this work, variations of tocopherol isoforms (α, β, γ, and δ) in ripe fruits of these lines were studied. In parallel all tomato genes structurally associated with VTE biosynthesis were identified and mapped. Previously identified VTE QTL on chromosomes 6 and 9 were confirmed whilst novel ones were identified on chromosomes 7 and 8. Integrated analysis at the metabolic, genetic and genomic levels allowed us to propose 16 candidate loci putatively affecting tocopherol content in tomato. A comparative analysis revealed polymorphisms at nucleotide and amino acid levels between Solanum lycopersicum and S. pennellii candidate alleles. Moreover, evolutionary analyses showed the presence of codons evolving under both neutral and positive selection, which may explain the phenotypic differences between species. These data represent an important step in understanding the genetic determinants of VTE natural variation in tomato fruit and as such in the ability to improve the content of this important nutriceutical.