Evolution of the sexual reproduction in Veronica (Plantaginaceae) : phylogeny, phylogeography and invasion

Die geschlechtliche Fortpflanzung ist ein universelles Merkmal und erlaubt es genetische Variation innerhalb von Blütenpflanzen zu schaffen. Die Evolution der sexuellen und reproduktiven Systeme wurde hier auf mehreren zeitlichen Ebenen, in verschiedenen Arten von Lebensraum studiert und mit fast allen möglichen Methoden im Labor, im Gewächshaus sowie im Feld untersucht. Drei Hauptteile sind in dieser Arbeit enthalten und entsprechen jeweils einem unterschiedlichen Niveau der Zeit: Gattung, Untergattung und Arten. Der erste Teil zeigt, dass die PO-Verhältnisse Untersuchungen systematisch in jeder Pflanzen-Gattung oder Untergattung untersucht werden müssen. Dieses güngstige, schnelle und leistungsstarke Werkzeug kann eine Vielzahl von Informationen über die Modi der Pflanzenreproduktion produzieren, ohne die Verwendung von teuren und langen Experimenten. Darüber hinaus könnte diese Maßnahme auch ergänzende Daten über die Taxonomie dieser untersuchten Gruppen geben. Das zweite Kapitel befasst sich mehr mit der Taxonomie der Ehrenpreis(Veronica)-Arten als die beiden anderen und zeigt, dass verschiedene Ereignisse der interspezifischen Reproduktion in einem der Hotspots der Artenvielfalt in Europa (der Balkan-Halbinsel) auftreten. Die Ergebnisse zeigen, dass morphologische und genetische Daten inkongruent sind und die Analyse der Taxonomie dieser Arten oder Unterart schwierig ist. Das letzteKapitel erzählt die Geschichte einer erfolgreichen Invasion, die während des letzten Jahrhunderts in Europa ablief trotz der Tatsache, dass die Arten obligate Fremdbefruchter sind und dass keine Samen-Produktion in der Region beobachtet wurde. Dieses Manuskript erläutert den Weg der Pflanze, um die “Baker-Regel“ zu umgehen. Diese Regel besagt, dass selbst-inkompatible Arten erfolgloser bei der Invasion neuer Lebensräume sind. Dennoch schafft es die hier untersuchte Art einen großen Teil der europäischen Rasen zu bevölkern und zeigt dabei genetische und morphologische Veränderungen auf diesem Weg.rnSchließlich wird in diesen drei verschiedenen Papieren versucht, die Verbindung zwischen der Mikro-und Makroevolution in der geschlechtlichen Fortpflanzun in Ehrenpreis (Veronica) unter Betracht verschiedener sexueller Systeme und der Stammesgeschichte, sowie der Migration zu klären.

Exploring host-pathogen interactions through protein microarray. Large-scale protein microarray analysis revealed novel human receptors for the staphylococcal immune evasion protein FLIPr and for the neisserial adhesin NadA

Adhesion, immune evasion and invasion are key determinants during bacterial pathogenesis. Pathogenic bacteria possess a wide variety of surface exposed and secreted proteins which allow them to adhere to tissues, escape the immune system and spread throughout the human body. Therefore, extensive contacts between the human and the bacterial extracellular proteomes take place at the host-pathogen interface at the protein level. Recent researches emphasized the importance of a global and deeper understanding of the molecular mechanisms which underlie bacterial immune evasion and pathogenesis. Through the use of a large-scale, unbiased, protein microarray-based approach and of wide libraries of human and bacterial purified proteins, novel host-pathogen interactions were identified. This approach was first applied to Staphylococcus aureus, cause of a wide variety of diseases ranging from skin infections to endocarditis and sepsis. The screening led to the identification of several novel interactions between the human and the S. aureus extracellular proteomes. The interaction between the S. aureus immune evasion protein FLIPr (formyl-peptide receptor like-1 inhibitory protein) and the human complement component C1q, key players of the offense-defense fighting, was characterized using label-free techniques and functional assays. The same approach was also applied to Neisseria meningitidis, major cause of bacterial meningitis and fulminant sepsis worldwide. The screening led to the identification of several potential human receptors for the neisserial adhesin A (NadA), an important adhesion protein and key determinant of meningococcal interactions with the human host at various stages. The interaction between NadA and human LOX-1 (low-density oxidized lipoprotein receptor) was confirmed using label-free technologies and cell binding experiments in vitro. Taken together, these two examples provided concrete insights into S. aureus and N. meningitidis pathogenesis, and identified protein microarray coupled with appropriate validation methodologies as a powerful large scale tool for host-pathogen interactions studies.

Immunophenotyping analysis in invasive micropapillary carcinoma of the breast: Role of CD24 and CD44 isoforms expression

We analyzed immunohistochemically the expression of CD24 and spliced variants of CD44v5 and v9 in invasive micropapillary carcinoma (IMPC) of the breast that is a rather aggressive tumor characterized by alteration of cells adhesion molecules, early lymph node metastases and poor prognosis. We analyzed 31 high-grade IMPCs and compared their expression to 22 high grade (G3) invasive ductal carcinomas of the breast (IDCs). We found a higher expression of CD24 in high-grade IMPCs with a peculiar inverted apical localization, compared to IDCs, showing a strong cytoplasmic staining; normal breast tissue resulted completely negative. IMPCs showed reduced expression of CD44v5 and CD44v9 compared with IDCs, but without a statistical significant difference. This study demonstrated that IMPC represents a distinct entity of breast carcinoma with high expression of CD24 with a typical inverted apical membrane pattern and reduction of CD44 isoforms v5 and v9, compared to IDCs. These features could explain the high lymph-vascular invasion propensity and higher metastatic capability of these tumors and could be a useful tool for a future targeted therapy.

Hybridization between distant lineages increases adaptive variation during a biological invasion: stickleback in Switzerland

The three-spined stickleback is a widespread Holarctic species complex that radiated from the sea into freshwaters after the retreat of the Pleistocene ice sheets. In Switzerland, sticklebacks were absent with the exception of the far northwest, but different introduced populations have expanded to occupy a wide range of habitats since the late 19th century. A well-studied adaptive phenotypic trait in sticklebacks is the number of lateral plates. With few exceptions, freshwater and marine populations in Europe are fixed for either the low plated phenotype or the fully plated phenotype, respectively. Switzerland, in contrast, harbours in close proximity the full range of phenotypic variation known from across the continent. We addressed the phylogeographic origins of Swiss sticklebacks using mitochondrial partial cytochrome b and control region sequences. We found only five different haplotypes but these originated from three distinct European regions, fixed for different plate phenotypes. These lineages occur largely in isolation at opposite ends of Switzerland, but co-occur in a large central part. Across the country, we found a strong correlation between a microsatellite linked to the high plate ectodysplasin allele and the mitochondrial haplotype from a region where the fully plated phenotype is fixed. Phylogenomic and population genomic analysis of 481 polymorphic amplified fragment length polymorphism loci indicate genetic admixture in the central part of the country. The same part of the country also carries elevated within-population phenotypic variation. We conclude that during the recent invasive range expansion of sticklebacks in Switzerland, adaptive and neutral between-population genetic variation was converted into within-population variation, raising the possibility that hybridization between colonizing lineages contributed to the ecological success of sticklebacks in Switzerland.

Identification of novel rhoptry proteins in Neospora caninum by LC/MS-MS analysis of subcellular fractions

Apicomplexan parasites possess an apical complex that is composed of two secretory organelles recognized as micronemes and rhoptries. Rhoptry contents are secreted into the parasitophorous vacuole during the host cell invasion process. Several rhoptry proteins have been identified in Toxoplasma gondii and seem to be involved in host-pathogen interactions and some of them are considered to be important virulence factors. Only one rhoptry protein, NcROP2, has been identified and extensively characterized in the closely related parasite Neospora caninum, and this has showed immunoprotective properties. Thus, with the aim of increasing knowledge of the rhoptry protein repertoire in N. caninum, a subcellular fractionation of tachyzoites was performed to obtain fractions enriched for this secretory organelle. 2-D SDS-PAGE followed by MS and LC/MS-MS were applied for fraction analysis and 8 potential novel rhoptry components (NcROP1, 5, 8, 30 and NcRON2, 3, 4, 8) and several kinases, proteases and phosphatases proteins were identified with a high homology to those previously found in T. gondii. Their existence in N. caninum tachyzoites suggests their involvement in similar events or pathways that occur in T. gondii. These novel proteins may be considered as targets that could be useful in the future development of immunoprophylactic measures.

Effects of epidermal growth factor on the invasion activity of the oral cancer cell lines HSC3 and SAS

Epidermal growth factor (EGF) is excreted in a high concentration in human saliva and modulates the growth and differentiation of various cancer cells. To elucidate the molecular mechanisms by which EGF affects oral cancer growth and invasion, we analyzed the Matrigel invasion activity of the cultured oral cancer cell line. Cells grown under the influence of EGF were subjected to Matrigel invasion assays and cells grown in the absence of EGF were used as controls. Gelatin-zymography and Northern blot analyses quantified the invasiveness and tumorigenicity. Chloramphenicol acetyltransferase assay (CAT assay) determined the EGF stimulation of matrix metalloproteinase (MMP) expression. EGF increased the number of cells penetrating a Matrigel membrane. Gelatin-zymography and Northern blot analysis revealed that MMP9 and Ets1 expressions correlated with EGF but MMP2 was not changed. a transient transfection assay revealed that EGF increased the promoter activities of the MMP9 genes in HSC3 and SAS cells. These results suggest that EGF increases the invasion activity of oral cancer cells partly by increasing MMP9.

Clinical and pathological analysis of epidural inflammation in intervertebral disk extrusion in dogs

BACKGROUND Little is known about the pathologic changes in the epidural space after intervertebral disk (IVD) extrusion in the dog. OBJECTIVES To analyze the pathology of the epidural inflammatory response, and to search for correlations between this process and clinical findings. METHODS Clinical data from 105 chondrodystrophic (CD) and nonchondrodystrophic (NCD) dogs with IVD extrusion were recorded. Epidural material from these dogs was examined histopathologically and immunohistochemically. Using statistical analysis, we searched for correlations between severity of epidural inflammation and various clinical and pathologic variables. RESULTS Most dogs exhibited an epidural inflammatory response, ranging from acute invasion of neutrophils to formation of chronic granulation tissue. The mononuclear inflammatory infiltrates consisted mostly of monocytes and macrophages and only few T and B cells. Surprisingly, chronic inflammatory patterns also were found in animals with an acute clinical history. Severity of the epidural inflammation correlated with degree of the epidural hemorrhage and nucleus pulposus calcification (P = .003 and .040), but not with age, chondrodystrophic phenotype, neurologic grade, back pain, pretreatment, or duration. The degree of inflammation was statistically (P = .021) inversely correlated with the ability to regain ambulation. CONCLUSION AND CLINICAL IMPORTANCE Epidural inflammation occurs in the majority of dogs with IVD extrusion and may develop long before the onset of clinical signs. Presence of calcified IVD material and hemorrhage in the epidural space may be the triggers of this lesion rather than an adaptive immune response to the nucleus pulposus as suggested in previous studies. Because epidural inflammation may affect outcome, further research is warranted.

Geographic analysis of RKIP expression and its clinical relevance in colorectal cancer

BACKGROUND This study evaluates the geographic expression pattern of Raf-1 Kinase Inhibitor Protein (RKIP) in colorectal cancer (CRC) in correlation with clinicopathological and molecular features, markers of epithelial-mesenchymal transition (EMT) and survival outcome. METHODS Whole-tissue sections of 220 well-characterised CRCs were immunostained for RKIP. NF-κB and E-Cadherin expression was assessed using a matched multi-punch tissue microarray. Analysis of mismatch repair (MMR) protein expression, B-Raf and KRAS mutations was performed. RKIP expression in normal mucosa, tumour centre, invasion front and tumour buds was each assessed for clinical relevance. RESULTS RKIP was diffusely expressed in normal mucosa and progressively lost towards tumour centre and front (P<0.0001). Only 0.9% of tumour buds were RKIP-positive. In the tumour centre, RKIP deficiency predicted metastatic disease (P=0.0307), vascular invasion (P=0.0506), tumour budding (P=0.0112) and an invasive border configuration (P=0.0084). Loss of RKIP correlated with NF-κB activation (P=0.0002) and loss of E-Cadherin (P<0.0001). Absence of RKIP was more common in MMR-deficient cancers (P=0.0191), while no impact of KRAS and B-Raf mutation was observed. RKIP in the tumour centre was identified as a strong prognostic indicator (HR (95% CI): 2.13 (1.27-3.56); P=0.0042) independently of TNM classification and therapy (P=0.0474). CONCLUSION The clinical relevance of RKIP expression as an independent prognostic factor is restricted to the tumour centre. Loss of RKIP predicts features of EMT and correlates with frequent distant metastasis.

Heterogeneity analysis of Metastasis Associated in Colon Cancer 1 (MACC1) for survival prognosis of colorectal cancer patients: a retrospective cohort study.

BACKGROUND Metastasis of colorectal cancer (CRC) is directly linked to patient survival. We previously identified the novel gene Metastasis Associated in Colon Cancer 1 (MACC1) in CRC and demonstrated its importance as metastasis inducer and prognostic biomarker. Here, we investigate the geographic expression pattern of MACC1 in colorectal adenocarcinoma and tumor buds in correlation with clinicopathological and molecular features for improvement of survival prognosis. METHODS We performed geographic MACC1 expression analysis in tumor center, invasive front and tumor buds on whole tissue sections of 187 well-characterized CRCs by immunohistochemistry. MACC1 expression in each geographic zone was analyzed with Mismatch repair (MMR)-status, BRAF/KRAS-mutations and CpG-island methylation. RESULTS MACC1 was significantly overexpressed in tumor tissue as compared to normal mucosa (p < 0.001). Within colorectal adenocarcinomas, a significant increase of MACC1 from tumor center to front (p = 0.0012) was detected. MACC1 was highly overexpressed in 55% tumor budding cells. Independent of geographic location, MACC1 predicted advanced pT and pN-stages, high grade tumor budding, venous and lymphatic invasion (p < 0.05). High MACC1 expression at the invasive front was decisive for prediction of metastasis (p = 0.0223) and poor survival (p = 0.0217). The geographic pattern of MACC1 did not correlate with MMR-status, BRAF/KRAS-mutations or CpG-island methylation. CONCLUSION MACC1 is differentially expressed in CRC. At the invasive front, MACC1 expression predicts best aggressive clinicopathological features, tumor budding, metastasis formation and poor survival outcome.

The Nile perch invasion in Lake Victoria: cause or consequence of the haplochromine decline?

We review alternative hypotheses and associated mechanisms to explain Lake Victoria’s Nile perch takeover and concurrent reduction in haplochromines through a (re)analysis of long term climate, limnological and stock observations in comparison with size-spectrum model predictions of co-existence, extinction and demographic change. The empirical observations are in agreement with the outcomes of the model containing two interacting species with life-histories matching Nile perch and a generalized haplochromine. The dynamic interactions may have depended on size related differences in early juvenile mortality: mouth-brooding haplochromines escape predation mortality in early life stages, unlike Nile perch that have miniscule planktonic eggs and larvae. In our model predation on the latter by planktivorous haplochromine fry act as a stabilizing factor for co-existence, but external mortality on the haplochromines would disrupt this balance in favor of Nile perch. To explain the observed switch, mortality on haplochromines would need to be much higher than the fishing mortality that can be realistically re-constructed from observations. Abrupt concomitant changes in algal and zooplankton composition, decreased water column transparency, and widespread hypoxia from increased eutrophication most likely caused haplochromine biomass decline. We hypothesize that the shift to Nile perch was a consequence of an externally caused, climate triggered, decrease in haplochromine biomass and associated recruitment failure rather than a direct cause of the introduction.

Stable isotope analysis on planktic foraminifera in sediment cores from the eastern Mediterranean sapropel formation

During the late Pleistocene, sapropels (layers of organic-carbon rich sediment) formed throughout the entire Eastern Mediterranean Basin in close association with glacial/interglacial transitions. The current theory for the mechanism of sapropel formation involves a density stratification of the water column, due to the invasion of a large quantity of low-saline water, which resulted in oxygen depletion of the bottom waters. Most workers believe that this low-salinity water was glacial meltwater that entered the Mediterranean via the Black Sea and a series of interconnected glacial lakes, but the suggestion also has been made that the freshwater originated from the Nile River. In this study the oxygen isotope values of planktonic foraminifera,Globigerinoides ruber, have been examined in six gravity cores and one piston core from the southern Levantine Basin, and compared with the oxygen isotope records ofG. ruber from other areas of the Eastern Mediterranean. This study deals mainly with the latest sapropel which was deposited approximately 7000 to 9000 years ago. Results indicate that Nile discharge probably does reduce salinities somewhat in the immediate area surrounding the mouth of the Nile, but this water is rapidly mixed with the highly saline waters of the easternmost Mediterranean. Using a mixing equation and surface water salinity limitations, an approximate oxygen isotope balance of surface waters was calculated for the time of latest sapropel deposition. This calculation shows that neither Nile River discharge nor Black Sea input (nor both together) are large enough to account for the large-scale oxygen isotope depletion associated with latest sapropel deposition in the Eastern Mediterranean. This suggests that part of the isotopic change at Termination I is probably due to increased surface water salinities during the last glacial maximum. In addition, evidence from the timing of sapropel 1 deposition and the dissolved oxygen balance indicates that deposition of the latest sapropel is associated with increased surface water production of biogenic material, as much as three times higher than that of present day.

Recurrent invasion and extinction of a selfish gene

Homing endonuclease genes show super-Mendelian inheritance, which allows them to spread in populations even when they are of no benefit to the host organism. To test the idea that regular horizontal transmission is necessary for the long-term persistence of these genes, we surveyed 20 species of yeasts for the ω-homing endonuclease gene and associated group I intron. The status of ω could be categorized into three states (functional, nonfunctional, or absent), and status was not clustered on the host phylogeny. Moreover, the phylogeny of ω differed significantly from that of the host, strong evidence of horizontal transmission. Further analyses indicate that horizontal transmission is more common than transposition, and that it occurs preferentially between closely related species. Parsimony analysis and coalescent theory suggest that there have been 15 horizontal transmission events in the ancestry of our yeast species, through simulations indicate that this value is probably an underestimate. Overall, the data support a cyclical model of invasion, degeneration, and loss, followed by reinvasion, and each of these transitions is estimated to occur about once every 2 million years. The data are thus consistent with the idea that frequent horizontal transmission is necessary for the long-term persistence of homing endonuclease genes, and further, that this requirement limits these genes to organisms with easily accessible germ lines. The data also show that mitochondrial DNA sequences are transferred intact between yeast species; if other genes do not show such high levels of horizontal transmission, it would be due to lack of selection, rather than lack of opportunity.

Post-European Parliament Elections Analysis

The 2014 European Parliament Elections might turn out to be not as "historic" as some people had predicted but many questions still need answering: Was the European Parliament on the brink of an invasion by Eurosceptics? Were these groups attempting to stop the Parliament from functioning? Had 'voter fatigue' come to an end? Or was this all hyperbole - is it all business as usual? Corina Stratulat and Janis A. Emmanouilidis analysed the impact and consequences of the 2014 European Parliament elections.

An Arginine Deprivation Response Pathway Is Induced in Leishmania during Macrophage Invasion

Amino acid sensing is an intracellular function that supports nutrient homeostasis, largely through controlled release of amino acids from lysosomal pools. The intracellular pathogen Leishmania resides and proliferates within human macrophage phagolysosomes. Here we describe a new pathway in Leishmania that specifically senses the extracellular levels of arginine, an amino acid that is essential for the parasite. During infection, the macrophage arginine pool is depleted due to its use to produce metabolites (NO and polyamines) that constitute part of the host defense response and its suppression, respectively. We found that parasites respond to this shortage of arginine by up-regulating expression and activity of the Leishmania arginine transporter (LdAAP3), as well as several other transporters. Our analysis indicates the parasite monitors arginine levels in the environment rather than the intracellular pools. Phosphoproteomics and genetic analysis indicates that the arginine-deprivation response is mediated through a mitogen-activated protein kinase-2-dependent signaling cascade.