Synthesis and evaluation of new heteroaryl nitrones with spin trap properties

A new series of heteroaryl nitrones were synthesized and evaluated as free radical traps due to the results showed in our previous report. The physicochemical characterization of these new nitrones by electron spin resonance (ESR) demonstrated their high capability to trap and stabilize different atom centered free radicals generated by the Fenton reaction. Additionally, we intensely studied them in terms of their physicochemical properties. Kinetic studies, including the use of a method based on competition and the hydroxyl adduct decay, gave the corresponding rate constants and half-lives at the physiological pH of these newly synthesized nitrones. New nitrones derived from quinoxaline 1,4-dioxide heterocycles were more suitable than DMPO to trap hydroxyl free radicals with a half-life longer than two hours. We explain some of the results using computational chemistry through density functional theory (DFT).

A new series of heteroaryl nitrones were synthesized and evaluated as free radical traps due to the results showed in our previous report.

76 Extracellular vesicles from oviduct and uterus in sequential culture improve the quality of bovine embryos produced invitro

Extracellular vesicles (EVs) are released by cells and transport cargo that affect functions of other cells. Oviductal fluid (OF) and uterine fluid (UF) have been shown to improve quality of embryos during invitro culture (Hamdi et al. 2017 Reprod. Fertil. Dev. 30, 935-945) which may be due to their content of EV (Lopera-Vásquez et al. 2017 Reproduction 153, 461-470). Thus, the aim of this study was to evaluate the effect of EVs from OF and UF on a sequential invitro culture system on the development and quality of bovine embryos. Zygotes were cultured in synthetic oviduct fluid (SOF) supplemented with 3mgmL−1 bovine serum albumin (BSA; n=1228) or 5% EV-depleted fetal calf serum (dFCS, n=1261) in the presence (BSAEV, n=1265 and dFCSEV, n=1253) or absence of 3×105 EVmL−1 from OF (Day 1 to Day 4) and UF (Day 4 to Day 9), mimicking invivo conditions. The EVs pooled from 5 oviducts (early luteal phase) and 5 uterine horns (middle luteal phase) from slaughtered heifers were isolated by a Size Exclusion Chromatography kit (Hansa BioMed). The EV size and concentration were assessed by the nanotracking analysis system and morphology by transmission electron microscopy. Embryo development was recorded on Days 7/9. Day 7/8 blastocysts were assessed for quality by staining with (a) Hoechst 33342 (10 µgmL−1, 30min) for total cell number, (b) Bodipy 493/503 (20 µgmL−1, 1h) for lipid content (lipid droplet area in µm2), and (c) for survival rate after vitrification/warming. Data were analysed by one-way ANOVA and Tukey test. The EV concentration was 2.97 and 7.98×1010 particlesmL−1, and mode size 137.2 and 151.2nm for OF and UF, respectively. Transmission electron microscopy confirmed EV presence and size, showing typical cup-shaped morphology. Blastocyst yield was lower (P<0.05) on Day 7 in the BSA groups (BSA: 15.7±1.9 and BSAEV: 15.2.4%) compared with serum groups (dFCS: 28.1±2.6 and dFCSEV: 30.1±2.9%) irrespective of EV supplementation; however, these differences were compensated at Days 8 and 9 (range: 30.0±3.2-40.8±3.9%). The EVs increased (P<0.05) blastocyst total cell number in dFCSEV (152.6±2.9) and BSAEV (140.5±1.5) compared with dFCS (117.9±2.0) and BSA groups (122.4±1.1). However, lipid content was decreased (P<0.05) in the presence of EVs only in dFCSEV (0.231±0.05µm2) compared with BSA (0.393±0.03µm2) and BSAEV (0.379±0.03µm2) groups. The dFCS did not differ from any group (0.371±0.05µm2; P>0.05). Blastocyst survival after vitrification/warming was high in all groups up to 72h (range: 80.0±3.8-100%; P>0.05). In conclusion, mimicking physiological conditions using EV from OF and UF during invitro culture does not affect development but improves embryo quality by increasing blastocyst total cell numbers and decreasing lipid contents. These results provide evidence of the association of the reproductive tract environment and developing embryo, confirming embryo-maternal communication. Funding was provided by MINECO-Spain AGL2015-70140-R; Y. N. Cajas, SENESCYT-Ecuador; C. L. V. Leal, FAPESP-Brazil 2017/20339-3.

A multilevel response approach reveals the Asian clam Corbicula largillierti as a mirror of aquatic pollution

The endobenthic bivalves are widely used as a bioindicators since they inhabit the sediment-water interface and are able to accumulate a different kind of contaminants. In the present work, we evaluated wild Corbicula largillierti (Phillippi, 1844) as a bioindicator of water quality in the central region of Argentina. The responses at different levels of the biological organization were used. We measured organochlorine pesticides (OCPs) and polychlorinated biphenyls (PCBs) levels in water and clams tissues. The biomarkers selected were enzymatic activities (Glutathione S-Transferase, Catalase, Acetyl-, Butyryl-cholinesterase, and Carboxylesterase) morphometry of the digestive gland, condition index and morphology of valves. In order to integrate all the responses a multivariate analysis and integrated stress index were applied. Our results showed the presence of contaminants along the studied river and the ability of C. largillierti to bioaccumulate them. All the biomarkers selected varied according to the water quality gradient, although there was no specific correlation with OCPs and PCBs levels. At the most polluted sites, the detoxification and oxidative stress enzymes, the morphometric analysis of the digestive gland and the variation in the morphology of the valves indicated the water quality degradation. The multivariate analyses allowed to discriminate the sites according to the different biomarker responses. The IBR index also showed a variation pattern according to the environmental quality gradient along the basin. According to the responses shown by C. largillierti we suggest this species as an useful bioindicator of aquatic pollution.

Determination of acute toxicity of ammonium in juvenile Patagonian blenny (Eleginops maclovinus)

Abstract Deionized ammonium (NH3) acute toxicity (LC50-96h) in Patagonian blenny juveniles (Eleginops maclovinus) was assessed. Concentrations of deionized ammonium in salt water were prepared by using 24.09 ± 2.1 g ammonium chloride (NH4Cl). Fish were exposed in triplicates to different ammonium concentrations: 0.05; 0.094; 0.175; 0.325 and 0.605 mg NH3 L-1. Additionally, a control group was included. Experimental fish were kept at a photoperiod of 16:8h. Average temperatures were 16.24 ± 1.40 °C. Oxygen concentration was 7.16 ± 0.40 mg L -1. Water pH was 7.89 ± 0.2. LC50-96 h, was estimated by using Probit statistical method (95% intervals) using EPA software (1993). Juveniles of E. maclovinus showed a LC50-96h of 0.413mg NH3 L-1 value, different from most marine species. This study presents the first record of ammonium toxicity in marine species of Chile.

Glucocorticoids Decrease Longitudinal Bone Growth in Pediatric Kidney Transplant Recipients by Stimulating the FGF23/FGFR3 Signaling Pathway

Renal transplantation (RTx) is an effective therapy to improve clinical outcomes in pediatric patients with terminal chronic kidney disease. However, chronic immunosuppression with glucocorticoids (GCs) reduces bone growth and BMD. The mechanisms causing GC-induced growth impairment have not been fully clarified. Fibroblast growth factor 23 (FGF23) is a peptide hormone that regulates phosphate homeostasis and bone growth. In pathological conditions, FGF23 excess or abnormal FGF receptors (FGFR) activity leads to bone growth impairment. Experimental data indicate that FGF23 expression is induced by chronic GC exposure. Therefore, we hypothesize that GCs impair bone growth by increasing FGF23 expression, which has direct effects on bone growth plate. In a post hoc analysis of a multicentric randomized clinical trial of prepubertal RTx children treated with early GC withdrawal or chronic GC treatment, we observed that GC withdrawal was associated with improvement in longitudinal growth and BMD, and lower plasma FGF23 levels as compared with a chronic GC group. In prepubertal rats, GC-induced bone growth retardation correlated with increased plasma FGF23 and bone FGF23 expression. Additionally, GC treatment decreased FGFR1 expression whereas it increased FGFR3 expression in mouse tibia explants. The GC-induced bone growth impairment in tibiae explants was prevented by blockade of FGF23 receptors using either a pan-FGFR antagonist (PD173074), a C-terminal FGF23 peptide (FGF23180-205) which blocks the binding of FGF23 to the FGFR-Klotho complex or a specific FGFR3 antagonist (P3). Finally, local administration of PD173074 into the tibia growth plate ameliorated cartilage growth impairment in GC-treated rats. These results show that GC treatment partially reduces longitudinal bone growth via upregulation of FGF23 and FGFR3 expression, thus suggesting that the FGF23/Klotho/FGFR3 axis at the growth plate could be a potential therapeutic target for the management of GC-induced growth impairment in children.

Prevalence of eosinophilic esophagitis: A multicenter study on a pediatric population evaluated at thirty-six Latin American gastroenterology centers

INTRODUCTION AND OBJECTIVE

Eosinophilic esophagitis is a chronic, immune-mediated disease described in case series and publications worldwide. Over the past twenty years, the authors of different studies have attempted to evaluate its incidence and prevalence. The objetive of the present study was to estimate the prevalence of eosinophilic esophagitis in a group of children seen at 36 pediatric gastroenterology centers in ten Latin American countries.

MATERIALS AND METHODS

A multicenter, observational, and cross-sectional study was conducted that estimated the period prevalence of eosinophilic esophagitis in children seen at outpatient consultation and that underwent diagnostic upper gastrointestinal endoscopy for any indication at 36 centers in 10 Latin American countries, within a 3-month time frame.

RESULTS

Between April and June 2016, 108 cases of eosinophilic esophagitis were evaluated. Likewise, an average of 29,253 outpatient consultations and 4,152 diagnostic upper gastrointestinal endoscopies were carried out at the 36 participating centers. The period prevalence of eosinophilic esophagitis in the population studied (n=29,253) was 3.69 cases×1,000 (95% CI: 3.04 to 4.44), and among the children that underwent routine upper gastrointestinal endoscopy (n=4,152), it was 26x1,000 (95% CI: 22.6 to 29.4).

CONCLUSIONS

The general period prevalence of eosinophilic esophagitis in a group of children evaluated at 36 Latin American pediatric gastroenterology centers was 3.69×1,000, and in the children that underwent endoscopy, it was 26×1,000. There was important prevalence variability between the participating countries and centers. The present analysis is the first study conducted on the prevalence of pediatric eosinophilic esophagitis in Latin America.

High prevalence of non-alcoholic fatty liver disease among hidradenitis suppurativa patients independent of classic metabolic risk factors

BACKGROUND

Some chronic inflammatory skin diseases, such as psoriasis, have been associated with an increased prevalence of non-alcoholic fatty liver disease (NAFLD). Nevertheless, this prevalence in hidradenitis suppurativa (HS) has not been assessed to date.

OBJECTIVES

To determine the prevalence of NAFLD in patients with HS and the risk factors associated with this disorder.

METHODS

This case-control study enrolled 70 HS patients and 150 age- and gender-matched controls who were evaluated by hepatic ultrasonography (US) and transient elastography (TE) after excluding other secondary causes of chronic liver disease. The diagnosis of NAFLD was established if US and/or TE were altered.

RESULTS

The prevalence of NAFLD was significantly increased in patients with HS compared to controls (72.9% vs. 24.7%: P < 0.001). In the multivariable regression model adjusted for age, sex and classic metabolic risk factors for NAFLD, HS was significantly and independently associated with the presence of NAFLD [OR 7.75 confidence interval (CI) 2.54-23.64; P < 0.001].

CONCLUSIONS

Our results show a high prevalence of NAFLD in HS patients independent of classic metabolic risk factors. Therefore, we suggest HS patients to be evaluated for NAFLD and managed accordingly.

Heterogeneous nuclear ribonucleoprotein C1 may control miR-30d levels in endometrial exosomes affecting early embryo implantation

STUDY QUESTION

Is there a specific mechanism to load the microRNA (miRNA), hsa-miR-30d, into exosomes to facilitate maternal communication with preimplantation embryos?

SUMMARY ANSWER

The heterogeneous nuclear ribonucleoprotein C1 (hnRNPC1) is involved in the internalization of endometrial miR-30d into exosomes to prepare for its subsequent incorporation into trophectoderm cells.

WHAT IS KNOWN ALREADY

Our group previously described a novel cell-to-cell communication mechanism involving the delivery of endometrial miRNAs from the maternal endometrium to the trophectoderm cells of preimplantation embryos. Specifically, human endometrial miR-30d is taken up by murine blastocysts causing the overexpression of certain genes involved in embryonic adhesion (Itb3, Itga7 and Cdh5) increasing embryo adhesion rates.

STUDY DESIGN, SIZE, DURATION

Transfer of maternal miR-30d to preimplantation embryos was confirmed by co-culture of wild-type (WT) and miR-30d knockout (KO) murine embryos with primary cultures of human endometrial epithelial cells (hEECs) in which mir-30d was labeled with specific Molecular Beacon (MB) or SmartFlare probes. Potential molecules responsible for the miR-30d loading into exosomes were purified by pull-down analysis with a biotinylated form of miR-30d on protein lysates from human endometrial exosomes, identified using mass spectrometry and assessed by flow cytometry, western blotting and co-localization studies. The role of hnRNPC1 in the miR-30d loading and transportation was interrogated by quantification of this miRNA in exosomes isolated from endometrial cells in which hnRNPC1 was transiently silenced using small interference RNA. Finally, the transfer of miR-30d to WT and KO embryos was assessed upon co-culture with sihnRNPC1 transfected cells.

PARTICIPANTS/MATERIALS, SETTING, METHODS

Murine embryos from miR-30d WT and KO mice, (strain MirC26tm1Mtm/Mmjax), were obtained by oviduct flushing of superovulated females. Endometrial Exosomes were purified by ultracentrifugation of supernatants from primary cultures of hEECs or Ishikawa cells. MB and Smartflare miR-30d probes were detected by confocal and/or transmission electron microscopy (TEM). hEECs and exosomes derived from them were subjected to pull-down with a biotinylated form of miR-30d. Captured proteins were identified by mass spectrometry (MS/MS). Western blotting was performed to detect hnRNPC1 and CYR61 in whole lysates, subcellular fractions and secreted vesicles from hEECs. Co-localization studies of the selected proteins with the exosomal marker CD63 were performed. FACS analysis was carried out to determine the presence of hnRNPC1 inside exosomes. Silencing of hnRNPC1 was conducted in the Ishikawa Cell Line with the Smart Pool Accell HNRNPC siRNA at a final concentration of 50 nM. RT-qPCRs were done to determine the messenger levels of miR-30d in cells and exosomes. Co-cultures of WT and KO embryos were established with Ishikawa cells double-transfected with sihnRPNC1 and MB probes.

MAIN RESULTS AND THE ROLE OF CHANCE

MS/MS analysis allowed us to identify hnRNPC1 as a possible protein to influence miR-30d loading into exosomes. Co-localization studies of hnRNPC1 with CD63 and FACS analyses suggested the presence of hnRNPC1 inside exosomes. Silencing of hnRNPC1 in Ishikawa cells resulted in a sharp decrease of the levels of miR-30d in both epithelial-like cells (P = 0.0001) and exosomes (P = 0.0152), suggesting its potential role in miR-30d biogenesis and transfer. Co-culture assays of miR-30d KO embryos with sihnRNPC1 hEECs revealed a decrease in embryo-miR-30d acquisition during the adhesion and invasion stages. In turn, transient silencing of hnRNPC1 results in a significant decrease of blastocyst adhesion compared to mock transfection conditions using Block-it, in both WT [Mean ± SD; 67 ± 10.0% vs. 38 ± 8.5%(P = 0.0006)] and miR-30d KO embryos [Mean ± SD; 50 ± 11.5% vs. 26 ± 8.8% (P = 0.0029) (n = 2); 14 embryos transferred per condition tested].

LARGE-SCALE DATA

MS/MS data are available via ProteomeXchange with identifier PXD008773.

LIMITATIONS, REASONS FOR CAUTION

The Ishikawa Cell Line was used as a model of hEECs in silencing experiments due to the low survival rates of primary hEECs after transfection.

WIDER IMPLICATIONS OF THE FINDINGS

The data show that hnRNPC1 may be involved in the internalization of miR-30d inside exosomes. The decreased rates of embryo adhesion in endometrial epithelial-like cells transiently silenced with sihnRNPC1evidence that hnRNPC1 could be an important player in the maternal-embryo communication established in the early stages of implantation.

STUDY FUNDING AND COMPETING INTEREST(S)

This work was supported by the Miguel Servet Program Type I of Instituto de Salud Carlos III [CP13/00038]; FIS project [PI14/00545] to F.V.; the 'Atracció de Talent' Program from VLC-CAMPUS [UV-INV-PREDOC14-178329 to NB]; a Torres-Quevedo grant (PTQ-13-06133) by the Spanish Ministry of Economy and Competitiveness to IM and MINECO/FEDER Grant [SAF2015-67154-R] to C.S. The authors declare there is no conflict of interest.

Next generation flow for minimally-invasive blood characterization of MGUS and multiple myeloma at diagnosis based on circulating tumor plasma cells (CTPC)

Here, we investigated for the first time the frequency and number of circulating tumor plasma cells (CTPC) in peripheral blood (PB) of newly diagnosed patients with localized and systemic plasma cell neoplasms (PCN) using next-generation flow cytometry (NGF) and correlated our findings with the distinct diagnostic and prognostic categories of the disease. Overall, 508 samples from 264 newly diagnosed PCN patients, were studied. CTPC were detected in PB of all active multiple myeloma (MM; 100%), and smoldering MM (SMM) patients (100%), and in more than half (59%) monoclonal gammopathy of undetermined significance (MGUS) cases (p <0.0001); in contrast, CTPC were present in a small fraction of solitary plasmacytoma patients (18%). Higher numbers of CTPC in PB were associated with higher levels of BM infiltration and more adverse prognostic features, together with shorter time to progression from MGUS to MM (p <0.0001) and a shorter survival in MM patients with active disease requiring treatment (p ≤ 0.03). In summary, the presence of CTPC in PB as assessed by NGF at diagnosis, emerges as a hallmark of disseminated PCN, higher numbers of PB CTPC being strongly associated with a malignant disease behavior and a poorer outcome of both MGUS and MM.

Selecting native perennial plants for ecological intensification in Mediterranean greenhouse horticulture

Natural control by predators and parasitoids provides an important and often unnoticed ecosystem service to agricultural landscapes by reducing pest populations in crops. The current model of horticultural intensification in south-eastern Spain produces high yields but has also resulted in a landscape almost completely covered by plastic. Promoting natural areas among greenhouses could enhance biodiversity, by being beneficial insects, and reduce pest pressure outdoors. The first step is to ascertain how pests and their natural enemies (NEs) use Mediterranean vegetation for selecting the best plants for pest suppression outdoors. The abundance of the two major horticultural pests, the tobacco whitefly, Bemisia tabaci, and the western flower thrips, Frankliniella occidentalis, together with their NEs, were assayed in 22 flowering perennial plants, which were newly planted in an experimental field surrounded by greenhouses. Eight plant species were identified as the most critical species for sustaining pest populations outdoors. A set of five plant species supported a medium level of pests, and another set of ten plant species supported the lowest level of both pests. Tobacco whitefly occurred in a few plants species, whereas western flower thrips occurred on almost all the plant species studied, and was favoured by the presence of flowers in perennial plants. The results suggest that plant diversity may provide relatively few acceptable host plants for tobacco whitefly than for western flower thrips. NEs were generally collected in plants that also supported abundance of pests, indicating that host/prey availability, more than food resources from flowers, was a stronger predictor of NE abundance in perennial plants. Field trials using the plants with the lowest host acceptance by pests are needed in order to ascertain whether pest abundance outdoors is reduced.

Usefulness of the twinkling artifact on Doppler ultrasound for the detection of breast microcalcifications

OBJECTIVE

To determine whether the twinkling artifact on Doppler ultrasound imaging corresponds to microcalcifications previously seen on mammograms and to evaluate the usefulness of this finding in the ultrasound management of suspicious microcalcifications.

MATERIAL AND METHODS

We used ultrasonography to prospectively examine 46 consecutive patients with groups of microcalcifications suspicious for malignancy identified at mammography, searching for the presence of the twinkling artifact to identify the microcalcifications. Once we identified the microcalcifications, we obtained core-needle biopsy specimens with 11G needles and then used X-rays to check the specimens for the presence of microcalcifications. We analyzed the percentage of detection and obtainment of microcalcifications by core-needle biopsy with this technique and the radiopathologic correlation. Microcalcifications that were not detected by ultrasound or discordant lesions were biopsied by stereotaxy at another center. We also used ultrasound guidance for preoperative marking with clips, usually orienting them radially.

RESULTS

We identified and biopsied 41 of the 46 lesions under ultrasound guidance, including 24 of 25 carcinomas (17 in situ). B-mode ultrasound was sufficient for biopsying the microcalcifications in 14 patients, although the presence of the twinkling artifact increased the number of microcalcifications detected and thus enabled more accurate preoperative marking. Thanks to the twinkling sign, we were able to identify 27 additional groups of microcalcifications (89% vs. 30%; p < 0.05). All the surgical specimens had margins free of disease.

CONCLUSIONS

The twinkling artifact is useful for microcalcifications in ultrasound examinations, enabling a significant increase in the yield of ultrasound-guided biopsies and better preoperative marking of groups of microcalcifications.

Primera evidencia de Chlamydia psittaci en huron sable (Mustella putorios furo) en Venezuela

Chlamydia psittaci (Cp) is an obligate intracellular bacterium, transmitted through aerosols from nasal and optic secretions, tissues, feces, and feathers. Although commonly identified in birds, genotypes have emerged that can infect new mammalian reservoirs. Therefore, of rectal swabs samples of five Mustella putorios furo individuals and a cloacal swab sample of Colinus cristatus in captivity, in Venezuela, were tested for Cp, using the nested PCR amplifying a segment of the 16S rDNA gene. The presence of Cp was found in four asymptomatic Mustela putorios furo and one symptomatic Colinus cristatus for avian chlamydiosis, indicating a new potential reservoir for Cp. The contact with excretions of infected Colinus cristatus and Psittaciformes, as well as overcrowding, inadequate ventilation, and inadequate sanitary conditions can favor Cp infection. The total number of Cp reservoirs is unknown; therefore, the noting and molecular characterization of isolates enable the understanding, distribution, and diversity of chlamydial agents in wildlife and animals in captivity.

Clinical impact of the subclonal architecture and mutational complexity in chronic lymphocytic leukemia

Genome studies of chronic lymphocytic leukemia (CLL) have revealed the remarkable subclonal heterogeneity of the tumors, but the clinical implications of this phenomenon are not well known. We assessed the mutational status of 28 CLL driver genes by deep-targeted next-generation sequencing and copy number alterations (CNA) in 406 previously untreated patients and 48 sequential samples. We detected small subclonal mutations (0.6-25% of cells) in nearly all genes (26/28), and they were the sole alteration in 22% of the mutated cases. CNA tended to be acquired early in the evolution of the disease and remained stable, whereas the mutational heterogeneity increased in a subset of tumors. The prognostic impact of different genes was related to the size of the mutated clone. Combining mutations and CNA, we observed that the accumulation of driver alterations (mutational complexity) gradually shortened the time to first treatment independently of the clonal architecture, IGHV status and Binet stage. Conversely, the overall survival was associated with the increasing subclonal diversity of the tumors but it was related to the age of patients, IGHV and TP53 status of the tumors. In conclusion, our study reveals that both the mutational complexity and subclonal diversity influence the evolution of CLL.

Are «off hours» intubations a risk factor for complications during intubation? A prospective, observational study

OBJECTIVE

To compare the complications and the difficulty of orotracheal intubation procedures performed in the Intensive Care Unit during the off-hours period and the on-hours period.

DESIGN

A prospective, observational and non-interventional cohort study covering a period of 27 months was carried out. Working days between 8:00 a. m. and 7:59 p. m. were considered «on-hours», while the remaining shifts were regarded as «off-hours».

SCOPE

An 18-bed surgical in a Intensive Care Unit of a third-level hospital.

PATIENTS

All orotracheal intubation patients admitted to the ICU from January 2015 to March 2017 were included. Patients were stratified into 2groups according to whether intubation was performed on-hours or off-hours.

INTERVENTIONS

Non-interventional study.

VARIABLES OF INTEREST

The reason for intubation, time and day on which intubation was performed, degree of intubation difficulty (number of attempts, Cormack-Lehane laryngoscopic vision, need for accessory material) and complications during intubation.

RESULTS

A total of 252 patients were intubated; of these, 132 were included in the on-hours group and 120 patients in the off-hours group. In the off-hours group we observed a greater percentage of urgent and emergent intubations compared to the on-hours group. However, no differences were found between the 2groups in relation to the other variables studied.

CONCLUSIONS

During the off-hours period, orotracheal intubation was not associated to a greater number of complications or to greater difficulty of the technique in our Unit.

Nothophytophthora gen. nov., a new sister genus of Phytophthora from natural and semi-natural ecosystems

During various surveys of Phytophthora diversity in Europe, Chile and Vietnam slow growing oomycete isolates were obtained from rhizosphere soil samples and small streams in natural and planted forest stands. Phylogenetic analyses of sequences from the nuclear ITS, LSU, β-tubulin and HSP90 loci and the mitochondrial cox1 and NADH1 genes revealed they belong to six new species of a new genus, officially described here as Nothophytophthora gen. nov., which clustered as sister group to Phytophthora. Nothophytophthora species share numerous morphological characters with Phytophthora: persistent (all Nothophytophthora spp.) and caducous (N. caduca, N. chlamydospora, N. valdiviana, N. vietnamensis) sporangia with variable shapes, internal differentiation of zoospores and internal, nested and extended (N. caduca, N. chlamydospora) and external (all Nothophytophthora spp.) sporangial proliferation; smooth-walled oogonia with amphigynous (N. amphigynosa) and paragynous (N. amphigynosa, N. intricata, N. vietnamensis) attachment of the antheridia; chlamydospores (N. chlamydospora) and hyphal swellings. Main differing features of the new genus are the presence of a conspicuous, opaque plug inside the sporangiophore close to the base of most mature sporangia in all known Nothophytophthora species and intraspecific co-occurrence of caducity and non-papillate sporangia with internal nested and extended proliferation in several Nothophytophthora species. Comparisons of morphological structures of both genera allow hypotheses about the morphology and ecology of their common ancestor which are discussed. Production of caducous sporangia by N. caduca, N. chlamydospora and N. valdiviana from Valdivian rainforests and N. vietnamensis from a mountain forest in Vietnam suggests a partially aerial lifestyle as adaptation to these humid habitats. Presence of tree dieback in all forests from which Nothophytophthora spp. were recovered and partial sporangial caducity of several Nothophytophthora species indicate a pathogenic rather than a saprophytic lifestyle. Isolation tests from symptomatic plant tissues in these forests and pathogenicity tests are urgently required to clarify the lifestyle of the six Nothophytophthora species.