Three members of the peroxiredoxin family were identified

in M. magneticum AMB-1. All purified recombinant proteins displayed thiol-dependent peroxidase activities. Allelic replacement mutagenesis revealed that, although the absence of the three peroxidase genes had no effect on either the growth or the formation of magnetosome under anaerobic conditions, the growth of mutants was compromised in AP24534 datasheet an aerobic culture. Moreover, an accelerated loss in the genomic ‘magnetosome island’ (MAI) was observed in the null mutants cultured in the presence of oxygen. Taken together, these data suggest that the thiol-peroxidases identified act as key antioxidants in magnetotactic bacteria and, as a result, contribute to maintaining their capacity to synthesize magnetosome by shielding the genetic stability of the genomic MAI in adaptation to constant physiological change and stress. Magnetotactic bacteria represent a diverse group of microorganisms that can synthesize membrane-enclosed magnetosomes, nanosized single-domain magnetic crystals, which cause them to orient and migrate along magnetic field lines (Komeili, 2007; Schuler, 2008). Magnetosome formation has been proposed

to be a complex process involving the functions of a variety of proteins. A unique genomic region named ‘magnetosome island’ (MAI) has thus been identified in magnetotactic bacteria and proved to be GKT137831 concentration the genetic basis for the synthesis of magnetosome (Fukuda et al., 2006; Jogler et al., 2009). While magnetotaxis was originally proposed to help guide cells to reach the less oxygenated regions of aquatic habitats, it became clear later that magnetotactic bacteria would take advantage of both magnetotaxis and aerotaxis to alternate their swimming direction to locate the optimal oxygen concentration (Smith et al., 2006). Compared with polar magneto-aerotactic bacteria, DCLK1 axial magnetotactic spirilla

including Magnetospirillum magneticum AMB-1 combine a passive alignment along the magnetic field with an active, temporal oxygen sensory mechanism to efficiently locate the optimal habitat zone (Zhulin et al., 1996; Zhao et al., 2007). Therefore, during this kind of aerotaxis, cells constantly sample the oxygen concentration to determine their direction of migration. The production of reactive oxygen species (ROS) in any organism that uses oxygen as a terminal electron acceptor has to be dealt with continuously to avoid the buildup of these reactive molecular species, which may result in oxidative damage to proteins, nucleic acids, and membranes (Storz & Imlay, 1999; Atack et al., 2008; Korshunov & Imlay, 2010). Over the course of evolution, bacteria have well been equipped with a variety of protective enzymatic systems to prevent ROS-mediated damage (Pesci et al., 1994; Chelikani et al., 2004; De Smet et al., 2006; Dubbs & Mongkolsuk, 2007).

Three independent cultures as well as protein extractions

and 2D-PAGE were performed to assess the reproducibility of the experiment. Gels were stained with Coomassie Brilliant Blue (CBB). CBB staining was carried out according to Neuhoff et al. (1988) with minor modifications and scanned in a Microtek 9800XL densitometer (Microtek) at 300 dpi resolution. Gels were stored in vacuum-sealed plastic bags at 4 °C. pdquestadvance software version 8.0 (Bio-Rad) was used for spot detection and quantitation, and to assess reproducibility. Protein spots chosen for mass spectrometric analysis (MS) were excised from the gels and manually digested. The gel pieces were rinsed three times with AmBic buffer (50 mM ammonium bicarbonate in 50% NVP-BKM120 HPLC grade methanol (Scharlau, Spain) and once with 10 mM DTT (Sigma-Aldrich). The gel pieces were rinsed

twice with AmBic buffer and dried in a SpeedVac before alkylation with 55 mM iodoacetamide (Sigma-Aldrich) in 50 mM ammonium bicarbonate. http://www.selleckchem.com/products/AC-220.html Once again, the gel pieces were rinsed with HPLC grade AmBic buffer (Scharlau), before being dehydrated by the addition of HPLC grade acetonitrile (Scharlau) and dried in a SpeedVac. Modified porcine trypsin (Promega) was added to the dry gel pieces at a final concentration of 20 ng μL−1 in 20 mM ammonium bicarbonate, incubating them at 37 °C for 16 h. Peptides were extracted three times by 20 min incubation in 40 μL of 60% acetonitrile in 0.5% HCOOH (formic acid). The resulting peptide extracts were pooled, concentrated in a SpeedVac and stored at −20 °C. A combination of matrix-assisted laser-desorption-ionization time-of-flight mass spectrometry (MALDI-TOF) (MS) and MALDI-TOF/TOF (MS/MS) was used for protein identification according to the following procedure. Dried samples were dissolved

in 4 μL 17-DMAG (Alvespimycin) HCl of 0.5% formic acid. Equal volumes (0.5 μL) of peptide and matrix solution, consisting of 3 mg α-cyano-4-hydroxycinnamic acid (CHCA) dissolved in 1 mL of 50% acetonitrile in 0.1% trifluoroacetic acid, were deposited using the thin-layer method onto a 384 Opti-TOF MALDI plate (Applied Biosystems). Mass spectrometric data were obtained in an automated analysis loop using a 4800 MALDI-TOF/TOF analyzer (Applied Biosystems). MS spectra were acquired in reflectron positive-ion mode with an Nd:YAG, 355-nm wavelength laser, averaging 1000 laser shots, and at least three trypsin autolysis peaks were used as internal calibration. All MS/MS spectra were performed by selecting the precursors with a relative resolution of 300 full width at half maximum and metastable suppression. Automated analysis of mass data was achieved using the 4000 Series explorer software V3.5. Peptide mass fingerprinting (PMF) and peptide fragmentation spectra data of each sample were combined through the GPSexplorer Software v3.6 using mascot software v2.1.

“
“During cerebral cortex development, post-mitotic neurons interact with radial glial fibers and the extracellular environment to migrate away from the ventricular region and form a correct laminar structure. Integrin receptors are major mediators of cell–cell and cell–extracellular matrix interactions. Several integrin heterodimers are present during formation of the cortical layers. selleck The α5β1 receptor is expressed in the neural progenitors of the ventricular zone during cerebral cortex formation. Using in utero electroporation to introduce short hairpin RNAs in the brain at embryonic day

15.5, we were able to inhibit acutely the expression of α5 integrin in the developing cortex. The knockdown of α5 integrin expression level in neural precursors resulted in an inhibition of radial migration, without perturbing the glial scaffold. Moreover, the same inhibitory effect on neuronal migration was observed after electroporation of a Cre recombinase expression plasmid into the neural progenitors of conditional knockout mice for α5 integrin. In both types of experiments, the electroporated cells expressing reduced levels of α5 integrin accumulated in the premigratory region with an abnormal morphology.

At postnatal day 2, ectopic neurons were observed see more in cortical layer V, while a deficit of neurons was observed in cortical layer II–IV. We show that these neurons do not express a layer V-specific marker, suggesting that they have not undergone premature differentiation. Overall, these results indicate that α5β1 integrin functions in the regulation of neural morphology and migration during cortical development, playing a role in cortical lamination.

“
“After traumatic spinal cord injury (SCI), endoplasmic reticulum (ER) stress exacerbates secondary injury, leading to expansion of demyelination and reduced remyelination due to oligodendrocyte precursor cell (OPC) apoptosis. Although recent studies have revealed that amiloride controls ER stress and leads to improvement in several neurological Exoribonuclease disorders including SCI, its mechanism is not completely understood. Here, we used a rat SCI model to assess the effects of amiloride on functional recovery, secondary damage expansion, ER stress-induced cell death and OPC survival. Hindlimb function in rats with spinal cord contusion significantly improved after amiloride administration. Amiloride significantly decreased the expression of the pro-apoptotic transcription factor CHOP in the injured spinal cord and significantly increased the expression of the ER chaperone GRP78, which protects cells against ER stress.

The 1-year dietary intervention was long enough to show improvement in eating habits and in habits for quenching thirst, and some decrease in the LF values of molars. “
“Aim of this in vitro study was to compare self-etch adhesives regarding microtensile bond strength (μ-TBS) to dentin of primary teeth. Fifty freshly extracted primary molars were ground to expose caries-free

dentin. Specimens were bonded with ten self-etch adhesives (iBond self-etch/Heraeus, Xeno V+/Dentsply, G-Bond, Gaenial Bond/GC, BeautiBond/Shofu, AdheSE One F/Ivoclar Vivadent, Adper Easy Bond/3M ESPE, Clearfil SE Bond/Kuraray, OptiBond XTR/KerrHawe, Prime&Bond NT/Dentsply). After 24-h storage (distilled Osimertinib purchase water, 37°C), resin–dentin beams were cut and 848 resin–dentin sticks were subjected to μ-TBS tests. Fracture analysis was carried out at 40× magnification under a fluorescence microscope and under a SEM. Three adhesives (iBond SE, Clearfil SE Bond, Prime&Bond NT) did not suffer pre-test failures (PTF). AdheSE One F revealed the largest portion of PTF (28%; P < 0.05). Clearfil SE Bond and OptiBond XTR exhibited more cohesive fractures than the other adhesives (77.3% vs 64.8%; P < 0.05). iBond SE, Gaenial Bond, Clearfil SE, and OptiBond XTR

achieved μ-TBS of >60 MPa, whereas Xeno V+ and AdheSE One F ranged only at ~20 MPa (P < 0.05). Within the limits of this study, the self-etch adhesives under investigation proved different extents of initial μ-TBS

to Epigenetic inhibitor manufacturer primary dentin with iBond SE, Gaenial Bond, Clearfil SE, and OptiBond XTR having been most successful. “
“International Journal of Paediatric Dentistry 2011; 21: 471–475 Background.  Primary Sjögren selleck compound syndrome is a rare autoimmune disease, especially in children, mainly affecting girls (77%), and usually diagnosed around 10 years of age. Diagnosis during childhood is difficult, especially because of the diversity of the clinical presentation and difficulty obtaining reliable history data, accounting for a higher frequency of underdiagnosed cases. Differential conditions should be considered, especially the ones that promote xerostomia, such as diabetes, ectodermal dysplasia, rheumatoid arthritis, scleroderma, systemic lupus erythematosus, sarcoidosis, lymphoma, HIV and HTLV infection. Conditions associated with parotid enlargement should also be excluded, including juvenile recurrent parotitis (JRP), sialadenosis, sarcoidosis, lymphoma, infectious parotitis caused by streptococcal and staphylococcal infections, viral infections (paramyxovirus, Epstein–Barr virus, cytomegalovirus, and parvovirus), and diffuse infiltrative lymphocytosis syndrome (associated with HIV infection), and rare congenital conditions, such as polycystic parotid disease. Case report.  A paediatric female patient was referred to our clinic for dental treatment complaining about dry mouth, oral discomfort, and dysphagia.

, 2012). Recently, the variation in manure-amended soil survival capability among 18 E. coli O157 isolates was studied and a strong relationship between the individual metabolic capacity and long-term survival of the strains was observed (Franz et al., 2011). In particular, oxidative capacity on propionic acid, α-ketobutyric acid and MK-2206 research buy α-hydroxybutyric acid was strongly correlated with enhanced survival. Recent gene expression studies showed that rpoS mutants of E. coli O157 demonstrated an impaired ability to oxidize these three fatty acids

(Dong et al., 2009). Intrigued by this observation, the isolates used in the soil survival experiment (Franz et al., 2011) were screened for rpoS allelic variations. It was hypothesized that the conditions in manure-amended soil favour a functional RpoS system. Consequently, the manure-amended soil environment would be an unlikely source of rpoS mutants. As the bovine intestine forms the principal reservoir of E. coli O157 and humans can be considered a transient host with distinct conditions in

the gastrointestinal tract, it was hypothesized that the human gut could provide a niche for the rise and selection of rpoS mutants. Therefore, the prevalence of rpoS allelic variations among a set of 187 E. coli O157 isolates of bovine, food and human origin (Franz et al., 2012) was determined. The detailed characteristics of the E. coli O157 strains used in the manure-amended soil survival find more study as well as the set of 187 strains (73 bovine, 29 food and 85 human clinical isolates) have been described in detail previously (Franz et al., 2011, 2012). Most of the strains were isolated and stored, and have no history of prolonged laboratory use. The complete rpoS gene was amplified using the following primers: rpoS_−130F, 5′-CTTGCATTTTGAAATTCGTTAC-3′; and rpoS_+125R, 5′-GATGATGAACACATAGGATGC-3′ in a 50-μL PCR mixture containing 1 × PCR buffer (Invitrogen BV, Breda, the Netherlands), 2.5 mM MgCl2, 0.2 mM

dNTPs, 0.2 μM of each primer, 1 U Taq DNA polymerase (Invitrogen BV) and 2 μL DNA template (± 20 ng). The following PCR programme was used: one cycle of 95 °C for 5 min; 35 cycles of 95 °C for 30 s, 56 °C for 30 s and Cell Penetrating Peptide 72 °C for 60 s; one cycle 72 °C for 10 min. The PCR product was treated with ExoSAP-IT (GE Healthcare, Diegem, the Netherlands) to remove unwanted deoxynucleotides and primers. The sequence of the generated PCR product was determined using the ABI Big Dye Terminator kit and an ABI 3730 DNA Analyzer (Applied Biosystems, Bleiswijk, the Netherlands). The PCR primers were used for sequencing as well two others: rpoS_−4F, 5′-CCTTATGAGTCAGAATACGC-3′; rpoS_773R, 5′-CTCTGCTTCATATCGTCATC-3′. The functioning of the RpoS general stress resistance system was determined phenotypically by growth on succinate minimal medium (Chiang et al., 2011).

, 2008). In the

present study, we showed that AFB1, which is a nonphenolic, difuranocoumarin derivate, ICG-001 price can be oxidized by MnP from P. sordida YK-624. MnP removed approximately 70% of AFB1 after 24 h and was capable of removing AFB1 even in the absence of Tween 80. Although the complete elimination of AFB1 was not observed in the present study, it is thought that AFB1 is completely eliminated by the multitreatment with MnP. Mn(III), which is produced by MnP, could not oxidize AFB1 directly (data not shown). In the presence of Tween 80, lipid-derived peroxy radicals are produced (Bao et al., 1994) that may directly oxidize AFB1. On the other hand, formate and superoxide anion radicals, which are generated in the MnP reaction mixture in the absence of Tween 80 (Khindaria et

al., 1994), may mediate the oxidation of AFB1 by MnP alone. AFB1-8,9-dihydrodiol was generated as a metabolite generated from AFB1 by MnP. This metabolite has also been detected in some animals treated with AFB1 (Wu et al., 2009). AFB1-8,9-dihydrodiol is produced in some animals by the hydrolysis of AFB1-8,9-epoxide, which is formed when the 8,9-vinyl bond is oxidized by the microsomal cytochrome P450 system (Kuilman et al., 2000). Our current results suggest that similar reactions, namely the epoxidation of AFB1, followed by hydrolysis of AFB1-8,9-epoxide, occur when AFB1 is oxidized by MnP. As detailed in Fig. 6, we propose that the 8,9-vinyl bond of AFB1 can be oxidized by the peroxy radicals of Tween 80, formate radical, superoxide anion radical, or MnP directly (Tuynman et al., 2000) and that the epoxide thus generated see more is hydrolyzed spontaneously to AFB1-8,9-dihydrodiol

(Guengerich et al., 1996). The removal of toxicity is the most important goal for the biodegradation of environmental pollutions. Here, we showed that MnP not only removes but also detoxifies AFB1. The metabolite generated from AFB1 by MnP, AFB1-8,9-dihydrodiol, is less toxic than AFB1 because AFB1-8,9-dihydrodiol can rearrange and form a reactive dialdehyde that can react with primary amine groups in proteins by Schiff base reactions (Sabbioni et al., 1987). This prevents the formation of DNA adducts, which can cause mutations. Branched chain aminotransferase Although AFB1 eliminations by MnP (5–20 nkat) were almost the same, the decrease in mutagenic activity was higher with 20 nkat MnP (69.2%) than with 5 nkat MnP (49.4%), as shown in Fig. 4. It is thought that the amount of AFB1-8,9-epoxide in the reaction mixture containing 5 nkat MnP was higher than that in the reaction mixture containing 20 nkat MnP. In summary, we show for the first time that MnP can remove the mutagenic activity of AFB1 by converting it to AFB1-8,9-dihydrodiol. This system should therefore be useful in the bioremediation of AFB1-contaminated foods. “
“Fuel-contaminated soils from Station Nord (St.

Pectate lyases, amylases and xylanases are examples of probably the most ubiquitous hydrolytic enzymes secreted by Bacillus species (Priest, 1977; Tjalsma et al., 2004). Bacillus subtilis secretes at least seven different exoproteases including two major proteases (subtilisin and neutral metalloprotease E) and five minor proteases (bacillopeptidase F, Mpr, Epr Npr and Vpr) (Pero & Sloma, 1993, Table S1). These exoproteases digest proteins present in the environment, a response that is induced by low levels of available nitrogen (Hata et al., 2001).

Wild-type strains of B. subtilis that are deficient in the production of these extracellular proteolytic activities are also unable to swarm or form biofilms (Pero & Sloma, 1993; Connelly et al., 2004). The other active EPS category includes proteins find more that interact with substrates of different chemical nature that can be secreted during nutrient deprivation. Bacillus subtilis strains secrete many proteins involved in the degradation of a variety of molecules such as lipids, glutathione, phytic acid and extracellular nucleic acids to cope with conditions of low nitrogen (Priest, 1977; Tjalsma et al., 2004). Among the proteins active in

the formation of the exopolymeric matrix, special attention needs to be drawn to the recently identified Thiazovivin mw TasA protein. This protein is encoded by tasA, a gene expressed at the onset of sporulation in B. subtilis (Branda et al., 2006). TasA is required for the structural integrity of the matrix as well as biofilm development: it has been proposed that TasA forms amyloid fibers that bind cells together in the biofilm (Romero et al., 2010). TasA localization within the exopolymeric matrix is dependent on a functional yqxM gene, but the

role of YqxM in biofilm development is still unknown, another area that requires further investigation (Branda et al., 2006). The presence and role of extracellular DNA in B. subtilis strains is another topic that is poorly understood. In the close relative Bacillus cereus, biofilm formation requires DNA as part of the extracellular polymeric matrix (Vilain et al., 2009). DNA in biofilms may be involved in events of recombination that take place in natural environments (Spoering & Gilmore, 2006). Further studies on extracellular Molecular motor DNA in B. subtilis biofilms will help elucidate its role in natural environments. Microorganisms in nature are subject to sudden changes in the environmental conditions such as nutrient deprivation, desiccation, osmotic stress, action of antibiotic molecules released by other microorganisms, UV radiation and temperature variations. Bacillus subtilis can survive these environmental fluctuations, which are typical for soils, through several defense mechanisms (Setlow, 1992). Although spore formation is the main mechanism for long-term survival for B.

044 and Selleckchem BTK inhibitor P = 0.023, respectively), while KCC2-C568A embryos (n = 3) did not differ from their wild-type littermates (n = 3 per group; Fig. 4 O). In addition, KCC2-FL

and KCC2-ΔNTD embryos displayed a larger proportion of PSA-NCAM-positive cells in the ventricular and intermediate zones relative to the marginal zone than did wild-type littermates (30 and 26% more than wild-type; P = 0.012 and P = 0.0496, respectively; Fig. 4P). These findings suggest that radial migration of neuronal cells may be delayed in KCC2-FL and KCC2-ΔNTD embryos. The phenotypes of the KCC2-FL and KCC2-ΔNTD embryos indicate disturbances in neural crest cell migration. Neural crest contributes to both the facial bone structures and the bone marrow that produces blood cells (Inoue et al., 2004; Nagoshi et al., 2008). To investigate the distribution of migrating neural crest cells, E9.5 embryos were labelled with the neural crest

cell markers AP-2α and SOX-10 (Inoue et al., 2004). In wild-type embryos (n = 3 per group), several transverse sections in the hindbrain area showed a large amount of labelled neural crest cells outside the neural tube (Fig. 5A). SOX-10-positive cells were found both inside the neural tube, in a migrating find more stream projecting from the tube, and in areas further away from the tube. AP-2α-positive cells were mainly located in the areas with longer distances from the neural tube, and co-localized with SOX-10-positive cells, indicating that AP-2α expression turns on at later migratory stages. KCC2-FL (n = 4) and KCC2-ΔNTD (n = 3) embryos had a lower proportion of transverse sections with detectable neural crest DOCK10 (63 and 70% of wild-type; P = 0.019 and P = 0.011, respectively) and often displayed a diffuse pattern of these cells (Fig. 5B and C). In contrast, KCC2-C568A embryos (n = 4) did not

differ from wild-type embryos in the proportion of sections with neural crest (95% of wild-type; P = 0.846) nor the neural crest cell pattern (Fig. 5D). Connexins mediate early, direct and rapid communication between cells (Jaderstad et al., 2010) and play a key role in radial neuronal migration (Elias et al., 2007). Wild-type staining of connexin-43 showed a focused expression in cell processes of neural tube and neural crest cells (Fig. 6A). However, KCC2-FL and KCC2-ΔNTD embryos displayed numerous cells with a loss of this polarized expression pattern and with a more circumferential distribution of connexin-43 (Fig. 6B and C). This indicates that cell polarization, an essential feature of developing and migrating cells, might be disturbed in KCC2-FL and KCC2-ΔNTD embryos. KCC2 has been shown to interact with the actin cytoskeleton in an ion transport-independent manner (Li et al., 2007). We therefore labelled the actin cytoskeleton in the E9.5 embryos using phalloidin. Wild-type embryos displayed an enriched actin labelling at the adherens junctions lining the neural tube (Fig. 7A and E).

This was a prospective cohort study. We enrolled adults presenting for HIV testing at a community-based mobile testing unit (mobile testers) and at an HIV clinic (clinic testers) serving the same area. Testers diagnosed with HIV infection, regardless of testing Ruxolitinib mouse site, were offered immediate CD4 testing and instructed to retrieve results at the clinic. We assessed rates of linkage to care, defined as CD4 result retrieval within 90 days of HIV diagnosis and/or completion of antiretroviral therapy (ART) literacy training, for mobile vs. clinic testers. From July to November 2011, 6957 subjects were HIV tested (4703 mobile and 2254 clinic);

55% were female. Mobile testers had a lower HIV prevalence than clinic testers (10% vs. 36%, respectively), were younger (median 23 vs. 27 years, respectively) and were more likely to live >5 km or >30 min from the clinic (64% vs. 40%, respectively; all P < 0.001). Mobile testers were less likely to undergo CD4 testing (33% vs. 83%,

respectively) but more likely to have higher CD4 counts [median (interquartile range) 416 (287–587) cells/μL vs. 285 (136–482) cells/μL, respectively] than clinic testers Ceritinib chemical structure (both P < 0.001). Of those who tested HIV positive, 10% of mobile testers linked to care, vs. 72% of clinic testers (P < 0.001). Mobile HIV testing reaches people who are younger, who are more geographically remote, and who have earlier disease compared with clinic-based testing. Fewer mobile testers underwent CD4 testing and linked to HIV care. Enhancing linkage efforts may improve the impact of mobile testing for those with early HIV disease. "
“Objectives Across Hydroxychloroquine cost Europe, almost a third of individuals infected with HIV do not enter health care until late in the course of their infection. Surveillance to identify the extent to which late presentation occurs remains inadequate across Europe and is further complicated

by the lack of a common clinical definition of late presentation. The objective of this article is to present a consensus definition of late presentation of HIV infection. Methods Over the past year, two initiatives have moved towards a harmonized definition. In spring 2009, they joined efforts to identify a common definition of what is meant by a ‘late-presenting’ patient. Results Two definitions were agreed upon, as follows. Late presentation: persons presenting for care with a CD4 count below 350 cells/μL or presenting with an AIDS-defining event, regardless of the CD4 cell count. Presentation with advanced HIV disease: persons presenting for care with a CD4 count below 200 cells/μL or presenting with an AIDS-defining event, regardless of the CD4 cell count.

Of the cultures grown for 4 days in the dark and then illuminated for 24 h (see Fig. 2e), the wild-type strains contained significant amounts of carotenoids (35±2 and 28±4 μg g−1 dry mass, respectively), while only trace amounts were found in the three mutants. When the carotenoid amounts were sufficient for reliable determinations, nonpolar carotenoids were detected

in similar proportions in all the strains, ranging from 30% to 45% of the total carotenoid mixtures (Fig. 3). For more detailed qualitative assays, mycelial extracts of the wild-type strain FGSC 7603 and one representative ΔFvMAT1-2-1 mutant were subjected to HPLC analysis (Fig. 4). The same major individual carotenoids (mostly neurosporaxanthin, BYL719 mw torulene, Fluorouracil γ-carotene, β-carotene, and phytoene) were found in F. verticillioides as were found previously in other Fusarium species (Bindl et al., 1970; Avalos & Cerdá-Olmedo, 1987). However, the mutant contained

a higher proportion of phytoene and β-carotene (30.7% and 13.4%, respectively, compared with 20.4% and 3.4% in the wild type) and less of γ-carotene (19.9% against 36.7% in the wild type). This change suggests different patterns of downregulation of the carotenoid biosynthesis genes in the ΔFvMAT1-2-1 M15 mutant in relation to its wild-type parental strain (see the next section and Fig. 5). Parallel to carotenoid biosynthesis, mRNA levels of carRA, carB, carT, and carX genes of the carotenoid pathway (Fig. 1) are transiently induced 17-DMAG (Alvespimycin) HCl by illumination in F. fujikuroi (Prado et al., 2004; Thewes et al., 2005; Prado-Cabrero et al., 2007b). In the F. verticillioides genome (http://www.broadinstitute.org/annotation/genome/fusarium_verticillioides/MultiHome.html), highly conserved orthologues of these genes are found (carRA: FVEG_10718; carB: FVEG_10717; carT: FVEG_09251; and carX:

FVEG_10719.3, with 88%, 99%, 94%, and 85% identity at the protein level with F. fujikuroi counterparts), indicating the presence of the same carotenoid pathway in these two closely related fungi. We compared the transcript levels of carB, carRA, and carT in the wild-type strain, FGSC 7603 of F. verticillioides and its ΔFvMAT1-2-1 M15 mutant using qrt-PCR. Total RNA was isolated from mycelium samples of cultures grown for 4 days in the dark and then illuminated for 0.5, 2, 4, 6, 8, and 24 h, respectively. Very low mRNA levels of either carB, carRA, or carT were found in cultures of both strains when they were grown in the dark and sampled at the start of illumination (0 h), but the levels started to increase as early as 0.5 h following light onset. Expression levels of carT peaked at 0.