Comparative genome sequence analysis underscores mycoparasitism as the ancestral life style of Trichoderma

BACKGROUND

Mycoparasitism, a lifestyle where one fungus is parasitic on another fungus, has special relevance when the prey is a plant pathogen, providing a strategy for biological control of pests for plant protection. Probably, the most studied biocontrol agents are species of the genus Hypocrea/Trichoderma.

RESULTS

Here we report an analysis of the genome sequences of the two biocontrol species Trichoderma atroviride (teleomorph Hypocrea atroviridis) and Trichoderma virens (formerly Gliocladium virens, teleomorph Hypocrea virens), and a comparison with Trichoderma reesei (teleomorph Hypocrea jecorina). These three Trichoderma species display a remarkable conservation of gene order (78 to 96%), and a lack of active mobile elements probably due to repeat-induced point mutation. Several gene families are expanded in the two mycoparasitic species relative to T. reesei or other ascomycetes, and are overrepresented in non-syntenic genome regions. A phylogenetic analysis shows that T. reesei and T. virens are derived relative to T. atroviride. The mycoparasitism-specific genes thus arose in a common Trichoderma ancestor but were subsequently lost in T. reesei.

CONCLUSIONS

The data offer a better understanding of mycoparasitism, and thus enforce the development of improved biocontrol strains for efficient and environmentally friendly protection of plants.

Proton T (1) and T (2) relaxation times of human brain metabolites at 3 Tesla

Longitudinal and transverse relaxation times were measured for proton MRS signals from human brain metabolites at 3 T using a short-echo STEAM protocol and a surface coil as a transmitter/receiver. Volumes of interest containing mostly grey or mostly white matter were selected in occipital lobes of healthy subjects and relaxation times for the following resonances were obtained: N-acetylaspartate at 2.01 ppm (T(1) and T(2)), glutamate at 2.35 ppm (T(1)), creatine at 3.03 and 3.92 ppm (T(1) and T(2)), choline-containing substances at 3.22 ppm (T(1) and T(2)), myo-inositol at 3.57 and 3.65 ppm (T(1)) and the overlapping signals of glutamate and glutamine at 3.75 ppm (T(1)). The T(1) relaxation times obtained range from 0.97 to 1.47 s for grey matter and from 0.87 to 1.35 s for white matter. On the other hand, T(2) relaxation times range from 116 to 247 ms and from 141 to 295 ms in grey and white matter, respectively. Generally, the T(1) values measured at 3 T are close to the previously published data found at 1.5, 2 and 4.1 T. Also, the T(2) values confirm the previously observed decrease in transverse relaxation times with increasing static magnetic field. The proton relaxation times obtained will allow improved sequence design and spectra quantitation at 3 T, currently tested for enhanced clinical applications.

Comparative transcriptomics reveals different strategies of Trichoderma mycoparasitism

BACKGROUND

Trichoderma is a genus of mycotrophic filamentous fungi (teleomorph Hypocrea) which possess a bright variety of biotrophic and saprotrophic lifestyles. The ability to parasitize and/or kill other fungi (mycoparasitism) is used in plant protection against soil-borne fungal diseases (biological control, or biocontrol). To investigate mechanisms of mycoparasitism, we compared the transcriptional responses of cosmopolitan opportunistic species and powerful biocontrol agents Trichoderma atroviride and T. virens with tropical ecologically restricted species T. reesei during confrontations with a plant pathogenic fungus Rhizoctonia solani.

RESULTS

The three Trichoderma spp. exhibited a strikingly different transcriptomic response already before physical contact with alien hyphae. T. atroviride expressed an array of genes involved in production of secondary metabolites, GH16 ß-glucanases, various proteases and small secreted cysteine rich proteins. T. virens, on the other hand, expressed mainly the genes for biosynthesis of gliotoxin, respective precursors and also glutathione, which is necessary for gliotoxin biosynthesis. In contrast, T. reesei increased the expression of genes encoding cellulases and hemicellulases, and of the genes involved in solute transport. The majority of differentially regulated genes were orthologues present in all three species or both in T. atroviride and T. virens, indicating that the regulation of expression of these genes is different in the three Trichoderma spp. The genes expressed in all three fungi exhibited a nonrandom genomic distribution, indicating a possibility for their regulation via chromatin modification.

CONCLUSION

This genome-wide expression study demonstrates that the initial Trichoderma mycotrophy has differentiated into several alternative ecological strategies ranging from parasitism to predation and saprotrophy. It provides first insights into the mechanisms of interactions between Trichoderma and other fungi that may be exploited for further development of biofungicides.

Rapid impairment of skeletal muscle glucose transport/phosphorylation by free fatty acids in humans

The initial effects of free fatty acids (FFAs) on glucose transport/phosphorylation were studied in seven healthy men in the presence of elevated (1.44 +/- 0.16 mmol/l), basal (0.35 +/- 0.06 mmol/l), and low (<0.01 mmol/l; control) plasma FFA concentrations (P < 0.05 between all groups) during euglycemic-hyperinsulinemic clamps. Concentrations of glucose-6-phosphate (G-6-P), inorganic phosphate (Pi), phosphocreatine, ADP, and pH in calf muscle were measured every 3.2 min for 180 min by using 31P nuclear magnetic resonance spectroscopy. Rates of whole-body glucose uptake increased similarly until 140 min but thereafter declined by approximately 20% in the presence of basal and high FFAs (42.8 +/- 3.6 and 41.6 +/- 3.3 vs. control: 52.7 +/- 3.3 micromol x kg(-1) x min(-1), P < 0.05). The rise of intramuscular G-6-P concentrations was already blunted at 45 min of high FFA exposure (184 +/- 17 vs. control: 238 +/- 17 micromol/l, P = 0.008). At 180 min, G-6-P was lower in the presence of both high and basal FFAs (197 +/- 21 and 213 +/- 18 vs. control: 286 +/- 19 micromol/l, P < 0.05). Intramuscular pH decreased by -0.013 +/- 0.001 (P < 0.005) during control but increased by +0.008 +/- 0.002 (P < 0.05) during high FFA exposure, while Pi rose by approximately 0.39 mmol/l (P < 0.005) within 70 min and then slowly decreased in all studies. In conclusion, the lack of an initial peak and the early decline of muscle G-6-P concentrations suggest that even at physiological concentrations, FFAs primarily inhibit glucose transport/phosphorylation, preceding the reduction of whole-body glucose disposal by up to 120 min in humans.

The effect of renal insufficiency on mycophenolic acid protein binding

Mycophenolate mofetil (MMF) is commonly used in solid organ transplant recipients. MMF is converted to mycophenolic acid (MPA) upon reaching the systemic circulation. Many acidic drugs have altered protein binding in renal failure, and it is possible that MPA protein binding may be decreased. The authors studied 23 renal transplant recipients: 8 transplant patients (7 kidney, 1 kidney/pancreas) with chronic renal insufficiency (CRI) and 15 renal transplant patients with preserved renal function. Plasma was obtained for kinetic profiles of total MPA, free MPA, and its glucuronide metabolite (MPAG). Plasma was obtained from 10 hemodialysis patients and 8 healthy control volunteers to assess in vitro differences in MPA protein binding. Average free fraction of MPA in patients with chronic renal insufficiency was more than double that of patients with normal renal function (5.8 +/- 2.7 vs. 2.5 +/- 0.4, p < 0.01). Free MPAAUC was almost doubled in the patients with chronic renal insufficiency versus controls (2.04 +/- .08 vs. 1.03 +/- 0.6, p < 0.01). MPA protein binding is decreased, and free MPA concentrations are increased in patients with chronic renal failure.

IL-6 trans-signaling is essential for the development of hepatocellular carcinoma in mice

Hepatocellular carcinoma (HCC) is one of the most frequent tumors worldwide with rising incidence. The inflammatory cytokine, interleukin-6 (IL-6), is a critical mediator of HCC development. It can signal through two distinct pathways: the IL-6 classic and the IL-6 trans-signaling pathway. Whereas IL-6 classic signaling is important for innate and acquired immunity, IL-6 trans-signaling has been linked to accelerated liver regeneration and several chronic inflammatory pathologies. However, its implication in liver tumorigenesis has not been addressed yet. Here, we show that IL-6 trans-signaling, but not IL-6 classic signaling, is essential to promote hepatocellular carcinogenesis by two mechanisms: First, it prevents DNA-damage-induced hepatocyte apoptosis through suppression of p53 and enhances β-catenin activation and tumor proliferation. Second, IL-6 trans-signaling directly induces endothelial cell proliferation to promote tumor angiogenesis. Consequently, soluble gp130 fused to Fc transgenic mice lacking IL-6 trans-signaling are largely protected from tumor formation in a diethylnitrosamine/3,3',5,5'-tetrachloro-1,4-bis(pyridyloxy)benzene model of HCC.

CONCLUSION

IL-6 trans-signaling, and not IL-6 classic signaling, is mandatory for development of hepatocellular carcinogenesis. Therefore, specific inhibition of IL-6 trans-signaling, rather than total inhibition of IL-6 signaling, is sufficient to blunt tumor initiation and impair tumor progression without compromising IL-6 classic signaling-driven protective immune responses. (Hepatology 2017;65:89-103).

Assessment of (31)P relaxation times in the human calf muscle: a comparison between 3 T and 7 T in vivo

Phosphorus ((31)P) T(1) and T(2) relaxation times in the resting human calf muscle were assessed by interleaved, surface coil localized inversion recovery and frequency-selective spin-echo at 3 and 7 T. The obtained T(1) (mean +/- SD) decreased significantly (P < 0.05) from 3 to 7 T for phosphomonoesters (PME) (8.1 +/- 1.7 s to 3.1 +/- 0.9 s), phosphodiesters (PDE) (8.6 +/- 1.2 s to 6.0 +/- 1.1 s), phosphocreatine (PCr) (6.7 +/- 0.4 s to 4.0 +/- 0.2 s), gamma-NTP (nucleotide triphosphate) (5.5 +/- 0.4 s to 3.3 +/- 0.2 s), alpha-NTP (3.4 +/- 0.3 s to 1.8 +/- 0.1 s), and beta-NTP (3.9 +/- 0.4 s to 1.8 +/- 0.1 s), but not for inorganic phosphate (Pi) (6.9 +/- 0.6 s to 6.3 +/- 1.0 s). The decrease in T(2) was significant for Pi (153 +/- 9 ms to 109 +/- 17 ms), PDE (414 +/- 128 ms to 314 +/- 35 ms), PCr (354 +/- 16 ms to 217 +/- 14 ms), and gamma-NTP (61.9 +/- 8.6 ms to 29.0 +/- 3.3 ms). This decrease in T(1) with increasing field strength of up to 62% can be explained by the increasing influence of chemical shift anisotropy on relaxation mechanisms and may allow shorter measurements at higher field strengths or up to 62% additional signal-to-noise ratio (SNR) per unit time. The fully relaxed SNR increased by +96%, while the linewidth increased from 6.5 +/- 1.2 Hz to 11.2 +/- 1.9 Hz or +72%. At 7 T (31)P-MRS in the human calf muscle offers more than twice as much SNR per unit time in reduced measurement time compared to 3 T. This will facilitate in vivo (31)P-MRS of the human muscle at 7 T.

Feline leukaemia provirus load during the course of experimental infection and in naturally infected cats

Feline leukaemia virus (FeLV) infection in domestic cats can vary in its outcome (persistent, transient, no infection) for reasons that are not entirely known. It was hypothesized that the initial virus and provirus load could significantly influence the course of retrovirus infection. To determine the role of provirus loads, two methods of PCR, a nested PCR and a fluorogenic probe-based (TaqMan) real-time quantitative PCR, which were specific to the U3 region of FeLV-A were established. FeLV provirus in naturally and experimentally infected cats was then measured. Only 3 weeks after experimental FeLV-A infection, persistently infected cats demonstrated higher provirus loads and lower humoral immune responses than cats that had overcome antigenaemia. Lower initial provirus loads were associated with successful humoral immune responses. Unexpectedly, provirus in the buffy-coat cells of two cats that tested negative for the p27 antigen (a marker for viraemia) was also detected. In 597 Swiss cats, comparison of p27 antigen levels with PCR results revealed broad agreement. However, similar to the experimental situation, a significant number of animals (10%) was negative for the p27 antigen and FeLV-positive by PCR. These cats had a mean provirus load 300-fold lower than that of animals testing positive for the p27 antigen. In conclusion, an association between the provirus load and the outcome of FeLV infection was found. Detection of provirus carriers should contribute to further the control of FeLV. In addition, quantification of provirus loads will lead to a better understanding of FeLV pathogenesis and anti-retrovirus protective mechanisms.

In vivo quantification of intracerebral GABA by single-voxel (1)H-MRS-How reproducible are the results?

Gamma aminobutyric acid (GABA) is the major inhibitory neurotransmitter in the human brain. It plays a decisive role in a variety of nervous system disorders, such as anxiety disorders, epilepsy, schizophrenia, insomnia, and many others. The reproducibility of GABA quantification results obtained with a single-voxel spectroscopy J-difference editing sequence with Point Resolved Spectroscopy localization (MEGA-PRESS) was determined on a 3.0 Tesla MR scanner in healthy adults. Eleven volunteers were measured in long- and short-term intervals. Intra- and inter-subject reproducibility were evaluated. Internal referencing of GABA+ to total creatine (tCr) and water (H(2)O), as well as two different post-processing methods for the evaluation (signal integration and time-domain fitting) were compared. In all subjects lower coefficient of variation and therefore higher reproducibility can be observed for fitting compared to integration. The GABA+/tCr ratio performs better than the GABA+/H(2)O ratio or GABA+ without internal referencing for both fitting and integration (GABA+/tCr: 13.3% and 17.0%; GABA+/H(2)O: 15.0% and 17.8%; GABA+: 19.2% and 21.7%). Four-day measurements on three subjects showed higher intra- than inter-subject reproducibility (GABA+/tCr approximately 10-12%). With a coefficient of variation of about 13% for inter-subject and 10-12% for intra-subject variability of GABA+/tCr, this technique seems to be a precise tool that can detect GABA confidently. The results of this study show the reproducibility limitations of GABA quantification in vivo, which are necessary for further clinical studies.

A classical bipartite nuclear localization signal on Thogoto and influenza A virus nucleoproteins

We have previously shown that the nucleoprotein (NP) of Thogoto virus (THOV), a tick-borne member of the Orthomyxoviridae family, accumulates in the cell nucleus. Here we demonstrate that THOV NP contains a motif (KRxxxxxxxxxKTKK) at amino acid positions 179-193 that represents a classical bipartite nuclear localization signal (NLS). This sequence motif (named cNLS) was able to translocate a cytoplasmic 80-kDa reporter protein into the nucleus. Targeted mutations substituting lysines for alanines in the downstream cluster of the bipartite motif abolished the capacity of cNLS to mediate nuclear import. In contrast, identical mutations had no effect on nuclear localization when introduced into THOV NP, indicating that additional transport signals are present in NP. Amino-acid sequence comparisons revealed that THOV NP lacks the N-terminal nonconvential NLS (named here nNLS), which has been implicated in nuclear import of influenza A virus NP. Accordingly, THOV NP failed to interact in coprecipitation assays with the cellular NPI-1/3 transport factors of the karyopherin alpha family. A highly conserved motif identified in THOV NP was the so-called nuclear accumulation sequence (NAS). Mutating NAS alone, or in combination with cNLS, had no gross effect on the intracellular distribution of the protein, indicating that a functional NAS is not required for nuclear accumulation of THOV NP in mammalian cells. We also studied nuclear transport of influenza A/PR/8/34 virus NP. Interestingly, we found a cNLS motif at amino acid positions 198-216 in addition to the previously described nonconventional nNLS. To further assess the functional role of cNLS, nNLS, and NAS, we analyzed single, double, and triple mutants of influenza A virus NP. When nNLS was destroyed, the protein stayed in the cytoplasm as expected. When NAS was disrupted in addition to nNLS, the double mutant accumulated in the nucleus, suggesting that cNLS was active. Indeed, when cNLS was also inactivated, the triple mutant protein localized again predominantly to the cytoplasm. These findings suggest that NP of orthomyxoviruses have two independent NLSs, namely cNLS and nNLS. They further suggest that NAS and NLSs may assume opposing roles in nucleocytoplasmic transport of NP.

High-resolution mapping of human brain metabolites by free induction decay (1)H MRSI at 7 T

This work describes a new approach for high-spatial-resolution (1)H MRSI of the human brain at 7 T. (1)H MRSI at 7 T using conventional approaches, such as point-resolved spectroscopy and stimulated echo acquisition mode with volume head coils, is limited by technical difficulties, including chemical shift displacement errors, B(0)/B(1) inhomogeneities, a high specific absorption rate and decreased T(2) relaxation times. The method presented here is based on free induction decay acquisition with an ultrashort acquisition delay (TE*) of 1.3 ms. This allows full signal detection with negligible T(2) decay or J-modulation. Chemical shift displacement errors were reduced to below 5% per part per million in the in-slice direction and were eliminated in-plane. The B(1) sensitivity was reduced significantly and further corrected using flip angle maps. Specific absorption rate requirements were well below the limit (~20 % = 0.7 W/kg). The suppression of subcutaneous lipid signals was achieved by substantially improving the point-spread function. High-quality metabolic mapping of five important brain metabolites was achieved with high in-plane resolution (64 × 64 matrix with a 3.4 × 3.4 × 12 mm(3) nominal voxel size) in four healthy subjects. The ultrashort TE* increased the signal-to-noise ratio of J-coupled resonances, such as glutamate and myo-inositol, several-fold to enable the mapping of even these metabolites with high resolution. Four measurement repetitions in one healthy volunteer provided proof of the good reproducibility of this method. The high spatial resolution allowed the visualization of several anatomical structures on metabolic maps. Free induction decay MRSI is insensitive to T(2) decay, J-modulation, B(1) inhomogeneities and chemical shift displacement errors, and overcomes specific absorption rate restrictions at ultrahigh magnetic fields. This makes it a promising method for high-resolution (1)H MRSI at 7 T and above.

Transcriptomic response of the mycoparasitic fungus Trichoderma atroviride to the presence of a fungal prey

Background

Combating the action of plant pathogenic microorganisms by mycoparasitic fungi has been announced as an attractive biological alternative to the use of chemical fungicides since two decades. The fungal genus Trichoderma includes a high number of taxa which are able to recognize, combat and finally besiege and kill their prey. Only fragments of the biochemical processes related to this ability have been uncovered so far, however.

Results

We analyzed genome-wide gene expression changes during the begin of physical contact between Trichoderma atroviride and two plant pathogens Botrytis cinerea and Rhizoctonia solani, and compared with gene expression patterns of mycelial and conidiating cultures, respectively. About 3000 ESTs, representing about 900 genes, were obtained from each of these three growth conditions. 66 genes, represented by 442 ESTs, were specifically and significantly overexpressed during onset of mycoparasitism, and the expression of a subset thereof was verified by expression analysis. The upregulated genes comprised 18 KOG groups, but were most abundant from the groups representing posttranslational processing, and amino acid metabolism, and included components of the stress response, reaction to nitrogen shortage, signal transduction and lipid catabolism. Metabolic network analysis confirmed the upregulation of the genes for amino acid biosynthesis and of those involved in the catabolism of lipids and aminosugars.

Conclusion

The analysis of the genes overexpressed during the onset of mycoparasitism in T. atroviride has revealed that the fungus reacts to this condition with several previously undetected physiological reactions. These data enable a new and more comprehensive interpretation of the physiology of mycoparasitism, and will aid in the selection of traits for improvement of biocontrol strains by recombinant techniques.

Biocontrol of Fusarium head blight: interactions between Trichoderma and mycotoxigenic Fusarium

Fusarium head blight (FHB) is a re-emerging wheat disease that causes extensive damage through direct losses in yield and quality due to the presence of damaged Fusarium kernels and their associated mycotoxins such as the trichothecene deoxynivalenol (DON). Biological control, including the treatment of crop residues with antagonists, in order to reduce pathogen inoculum of FHB, holds considerable promise. Ten Trichoderma isolates, previously selected for their ability to grow in the presence of DON, were preliminarily investigated as potential antagonists against Fusarium culmorum and F. graminearum mycotoxigenic strains in plate confrontation assays. The three Trichoderma isolates showing antibiosis and mycoparasitism were evaluated for their capacity to inhibit DON production by F. graminearum and F. culmorum on two natural substrates. The expression of some chitinase-encoding genes by the two best resulting Trichoderma strains, during interaction with F. culmorum and F. graminearum, was monitored. All investigated genes from chitinase subgroups A, B and the new subgroup C responded to mycoparasitic conditions and were upregulated before contact and/or when in contact with the host. T. gamsii 6085, the best antagonist, was finally used in a competition test against F. culmorum and F. graminearum on natural substrates, using a qPCR approach to evaluate its effect on the pathogen's growth and DON production in haulms and rice. This test confirmed the ability of T. gamsii 6085 to antagonize the pathogens on rice. On wheat haulms, an extreme oligotrophic environment, T. gamsii 6085 seemed to develop very poorly and the growth of both the pathogens was unaffected by the presence of the antagonist.

Evidence for a sex-specific residual effect of cannabis on visuospatial memory

BACKGROUND

In an exploratory study, we used a novel computerized battery of neuropsychological tests of attention to assess residual cognitive impairment in marijuana users.

METHODS

We compared 25 college students who were heavy marijuana smokers (who had smoked a median of 29 days in the last 30 days) with 30 students who were light smokers (who had smoked a median of 1 day in the last 30 days). All subjects were tested after a supervised period of abstinence from marijuana and other drugs lasting at least 19 h.

RESULTS

Differences between the overall groups of heavy and light smokers did not reach statistical significance on the four subtests of attention administered. However, upon examining data for the two sexes separately, marked and significant differences were found between heavy- and light-smoking women on the subtest examining visuospatial memory. On this test, subjects were required to examine a 6 x 6 'checkerboard' of squares in which certain squares were shaded. The shaded squares were then erased and the subject was required to indicate with the mouse which squares had formerly been shaded. Increasing numbers of shaded squares were presented at each trial. The heavy-smoking women remembered significantly fewer squares on this test, and they made significantly more errors than the light-smoking women. These differences persisted despite different methods of analysis and consideration for possible confounding variables.

CONCLUSIONS

This observation suggests that it may be important to study the residual effects of marijuana on men and women separately-particularly since women have been greatly underrepresented in previous studies in this area.

Analysis of subgroup C of fungal chitinases containing chitin-binding and LysM modules in the mycoparasite Trichoderma atroviride

Fungi have a plethora of chitinases, which can be phylogenetically divided into three subgroups (A, B and C). Subgroup C (sgC) chitinases are especially interesting due to their multiple carbohydrate-binding modules, but they have not been investigated in detail yet. In this study, we analyzed sgC chitinases in the mycoparasites Trichoderma atroviride and Trichoderma virens. The expression of sgC chitinase genes in T. atroviride was induced during mycoparasitism of the fungal prey Botrytis cinerea, but not Rhizoctonia solani and correspondingly only by fungal cell walls of the former. Interestingly, only few sgC chitinase genes were inducible by chitin, suggesting that non-chitinous cell wall components can act as inducers. In contrast, the transcriptional profile of the most abundantly expressed sgC chitinase gene tac6 indicated a role of the protein in hyphal network formation. This shows that sgC chitinases have diverse functions and are not only involved in the mycoparasitic attack. However, sequence analysis and 3D modelling revealed that TAC6 and also its ortholog in T. virens have potentially detrimental deletions in the substrate-binding site and are thus probably not catalytically active enzymes. Genomic analysis showed that the genes neighboring sgC chitinases often encode proteins that are solely composed of multiple LysM modules, which were induced by similar stimuli as their neighboring sgC chitinase genes. This study provides first insights into fungal sgC chitinases and their associated LysM proteins.

Gas-phase hydrolysis of proteins and peptides

A simplified gas-phase hydrolysis procedure for proteins and peptides is described. The apparatus consists of a glass vacuum desiccator, a ceramic plate, and a Teflon ring. The method was shown to give reproducible compositions for hydrolysis of human serum albumin and microanalysis of alpha-melanocyte stimulating hormone including the quantitation of as little as one residue of tryptophan. It minimizes sample handling and allows for the simultaneous hydrolysis of a large number of samples.

Late-onset neurologic disease in glutaryl-CoA dehydrogenase deficiency

Neurologic disease in glutaryl-CoA dehydrogenase (GCDH) deficiency usually presents with acute encephalopathic crises before 2 years of age. The authors report two previously asymptomatic patients with macrocephaly presenting with progressive neurologic deterioration and a severe leukoencephalopathy during adolescence or adulthood.

Post-harvest gene escape and approaches for minimizing it

Abstract

Data about gene escape by seeds and volunteers were compiled for the first time in one study for several crops, i.e. wheat (Triticum aestivum), sugar beet (Beta vulgaris), oilseed rape/canola (Brassica napus) and maize (Zea mays). These species represent important genetically modified (GM) crops with herbicide tolerance (HT) or insect resistance (Bt), show different levels of autogamy and allogamy and are grown in different climatic zones of the world. Post-harvest measures and strategies were identified for minimizing gene escape from these crops. All species were found to cause problems in terms of gene escape by seed and volunteers though there are important differences between species and climatic zones. Post-harvest tillage was identified as a key factor for reducing the soil seed bank and volunteers. Timing and intensity of tillage has to be specifically adapted to the dormancy characteristics of each species. Furthermore, there is a close interaction between gene escape and the cropping system. Rotations should avoid the same crop or other critical crops in temporal vicinity to the GM crop in order to keep volunteer populations below a critical density. In no-till systems with use of HT varieties, HT volunteers can reduce the efficiency of the whole system if additional herbicides have to be applied. Seed impurities and admixtures during seed production are another major source of gene escape. Since seed lots of certified growers present less adventitious presence of other varieties, these should be preferred to farm-saved seeds. Education of farmers, cleaning of equipment, control measures and separate production and supply chains are additionally important to minimize gene escape.

Temporal lobe proton magnetic resonance spectroscopy of patients with first-episode psychosis

OBJECTIVE

The authors measured the ratio of N-acetyl aspartate (a putative neuronal marker) to creatine-phosphocreatine in patients with first-episode psychosis by using proton magnetic resonance spectroscopy (MRS).

METHOD

Temporal lobe 1H MRS was performed bilaterally on 13 patients with first-episode psychosis and 15 comparison subjects. The N-acetyl aspartate/creatine-phosphocreatine and choline/creatine-phosphocreatine ratios were determined.

RESULTS

The N-acetyl aspartate/creatine-phosphocreatine ratio of the psychotic patients was significantly lower than that of the comparison subjects.

CONCLUSIONS

These preliminary data suggest that abnormalities in temporal lobe N-acetyl aspartate concentration are present early in psychotic illness.

Self-assembly at air/water interfaces and carbohydrate binding properties of the small secreted protein EPL1 from the fungus Trichoderma atroviride

The protein EPL1 from the fungus Trichoderma atroviride belongs to the cerato-platanin protein family. These proteins occur only in filamentous fungi and are associated with the induction of defense responses in plants and allergic reactions in humans. However, fungi with other lifestyles also express cerato-platanin proteins, and the primary function of this protein family has not yet been elucidated. In this study, we investigated the biochemical properties of the cerato-platanin protein EPL1 from T. atroviride. Our results showed that EPL1 readily self-assembles at air/water interfaces and forms protein layers that can be redissolved in water. These properties are reminiscent of hydrophobins, which are amphiphilic fungal proteins that accumulate at interfaces. Atomic force microscopy imaging showed that EPL1 assembles into irregular meshwork-like substructures. Furthermore, surface activity measurements with EPL1 revealed that, in contrast to hydrophobins, EPL1 increases the polarity of aqueous solutions and surfaces. In addition, EPL1 was found to bind to various forms of polymeric chitin. The T. atroviride genome contains three epl genes. epl1 was predominantly expressed during hyphal growth, whereas epl2 was mainly expressed during spore formation, suggesting that the respective proteins are involved in different biological processes. For epl3, no gene expression was detected under most growth conditions. Single and double gene knock-out strains of epl1 and epl2 did not reveal a detectable phenotype, showing that these proteins are not essential for fungal growth and development despite their abundant expression.

Molecular imaging of cancer: MR spectroscopy and beyond

Proton magnetic resonance spectroscopic imaging is a non-invasive diagnostic tool for the investigation of cancer metabolism. As an adjunct to morphologic and dynamic magnetic resonance imaging, it is routinely used for the staging, assessment of treatment response, and therapy monitoring in brain, breast, and prostate cancer. Recently, its application was extended to other cancerous diseases, such as malignant soft-tissue tumours, gastrointestinal and gynecological cancers, as well as nodal metastasis. In this review, we discuss the current and evolving clinical applications of proton magnetic resonance spectroscopic imaging. In addition, we will briefly discuss other evolving techniques, such as phosphorus magnetic resonance spectroscopic imaging, sodium imaging and diffusion-weighted imaging in cancer assessment.