Discovery of Novel Effector Protein Candidates Produced in the Dorsal Gland of Root-Knot Nematode Adult Females

Root-knot nematodes (RKN; Meloidogyne spp.) represent one of the most damaging groups of plant-parasitic nematodes. They secrete effector proteins through a protrusible stylet to manipulate host cells for their benefit. Stylet-secreted effector proteins are produced within specialized secretory esophageal gland cells, one dorsal (DG) and two subventral (SvG), whose activity differ throughout the nematode life cycle. Previous gland transcriptomic profiling studies identified dozens of candidate RKN effectors, but were focused on the juvenile stages of the nematode when the SvGs are most active. We developed a new approach to enrich for the active DGs of RKN M. incognita adult females for RNA and protein extraction. Female heads were manually cut from the body, and a combination of sonication/vortexing was used to dislodge contents inside the heads. DG-enriched fractions were collected by filtering using cell strainers. Comparative transcriptome profiling of pre-parasitic second-stage juveniles, female heads, and DG-enriched samples was conducted using RNA sequencing. Application of an established effector mining pipeline led to the identification of 83 candidate effector genes upregulated in DG-enriched samples of adult females that code for proteins with a predicted signal peptide, but lack transmembrane domains or homology to proteins in the free-living nematode Caenorhabditis elegans. In situ hybridization resulted in the identification of 14 new DG-specific candidate effectors expressed in adult females. Taken together, we have identified novel candidate Meloidogyne effector genes that may have essential roles during later stages of parasitism.

Experimental testing of a prototype cantilevered liquid-nitrogen-cooled silicon mirror

This report presents testing of a prototype cantilevered liquid-nitrogen-cooled silicon mirror. This mirror was designed to be the first mirror for the new soft X-ray beamlines to be built as part of the Advanced Light Source Upgrade. Test activities focused on fracture, heat transfer, modal response and distortion, and indicated that the mirror functions as intended.

Youngest presenting patient with dystonia 24 and review of the literature

Dystonia 24 was first reported in 2000 as an autosomal dominant cause of dystonia caused by variants in the ANO3 gene. Although many adults have been described with dystonia 24, since 2014, an increasing number of children have also been reported. Dystonia 24 should also be considered in the differential of a child with unexplained dystonia.

The novel cyst nematode effector protein 30D08 targets host nuclear functions to alter gene expression in feeding sites

Cyst nematodes deliver effector proteins into host cells to manipulate cellular processes and establish a metabolically hyperactive feeding site. The novel 30D08 effector protein is produced in the dorsal gland of parasitic juveniles, but its function has remained unknown. We demonstrate that expression of 30D08 contributes to nematode parasitism, the protein is packaged into secretory granules and it is targeted to the plant nucleus where it interacts with SMU2 (homolog of suppressor of mec-8 and unc-52 2), an auxiliary spliceosomal protein. We show that SMU2 is expressed in feeding sites and an smu2 mutant is less susceptible to nematode infection. In Arabidopsis expressing 30D08 under the SMU2 promoter, several genes were found to be alternatively spliced and the most abundant functional classes represented among differentially expressed genes were involved in RNA processing, transcription and binding, as well as in development, and hormone and secondary metabolism, representing key cellular processes known to be important for feeding site formation. In conclusion, we demonstrated that the 30D08 effector is secreted from the nematode and targeted to the plant nucleus where its interaction with a host auxiliary spliceosomal protein may alter the pre-mRNA splicing and expression of a subset of genes important for feeding site formation.

A cyst nematode effector binds to diverse plant proteins, increases nematode susceptibility and affects root morphology

Cyst nematodes are plant-parasitic roundworms that are of significance in many cropping systems around the world. Cyst nematode infection is facilitated by effector proteins secreted from the nematode into the plant host. The cDNAs of the 25A01-like effector family are novel sequences that were isolated from the oesophageal gland cells of the soybean cyst nematode (Heterodera glycines). To aid functional characterization, we identified an orthologous member of this protein family (Hs25A01) from the closely related sugar beet cyst nematode H. schachtii, which infects Arabidopsis. Constitutive expression of the Hs25A01 CDS in Arabidopsis plants caused a small increase in root length, accompanied by up to a 22% increase in susceptibility to H. schachtii. A plant-expressed RNA interference (RNAi) construct targeting Hs25A01 transcripts in invading nematodes significantly reduced host susceptibility to H. schachtii. These data document that Hs25A01 has physiological functions in planta and a role in cyst nematode parasitism. In vivo and in vitro binding assays confirmed the specific interactions of Hs25A01 with an Arabidopsis F-box-containing protein, a chalcone synthase and the translation initiation factor eIF-2 β subunit (eIF-2bs), making these proteins probable candidates for involvement in the observed changes in plant growth and parasitism. A role of eIF-2bs in the mediation of Hs25A01 virulence function is further supported by the observation that two independent eIF-2bs Arabidopsis knock-out lines were significantly more susceptible to H. schachtii.

Identification of potential host plant mimics of CLAVATA3/ESR (CLE)-like peptides from the plant-parasitic nematode Heterodera schachtii

In this article, we present the cloning of two CLAVATA3/ESR (CLE)-like genes, HsCLE1 and HsCLE2, from the beet cyst nematode Heterodera schachtii, a plant-parasitic cyst nematode with a relatively broad host range that includes the model plant Arabidopsis. CLEs are small secreted peptide ligands that play important roles in plant growth and development. By secreting peptide mimics of plant CLEs, the nematode can developmentally reprogramme root cells for the formation of unique feeding sites within host roots for its own benefit. Both HsCLE1 and HsCLE2 encode small secreted polypeptides with a conserved C-terminal CLE domain sharing highest similarity to Arabidopsis CLEs 1-7. Moreover, HsCLE2 contains a 12-amino-acid CLE motif that is identical to AtCLE5 and AtCLE6. Like all other plant and nematode CLEs identified to date, HsCLEs caused wuschel-like phenotypes when overexpressed in Arabidopsis, and this activity was abolished when the proteins were expressed without the CLE motif. HsCLEs could also function in planta without a signal peptide, highlighting the unique, yet conserved function of nematode CLE variable domains in trafficking CLE peptides for secretion. In a direct comparison of HsCLE2 overexpression phenotypes with those of AtCLE5 and AtCLE6, similar shoot and root phenotypes were observed. Exogenous application of 12-amino-acid synthetic peptides corresponding to the CLE motifs of HsCLEs and AtCLE5/6 suggests that the function of this class of CLEs may be subject to complex endogenous regulation. When seedlings were grown on high concentrations of peptide (10 µm), root growth was suppressed; however, when seedlings were grown on low concentrations of peptide (0.1 µm), root growth was stimulated. Together, these findings indicate that AtCLEs1-7 may be the target peptides mimicked by HsCLEs to promote parasitism.

The novel cyst nematode effector protein 19C07 interacts with the Arabidopsis auxin influx transporter LAX3 to control feeding site development

Plant-parasitic cyst nematodes penetrate plant roots and transform cells near the vasculature into specialized feeding sites called syncytia. Syncytia form by incorporating neighboring cells into a single fused cell by cell wall dissolution. This process is initiated via injection of esophageal gland cell effector proteins from the nematode stylet into the host cell. Once inside the cell, these proteins may interact with host proteins that regulate the phytohormone auxin, as cellular concentrations of auxin increase in developing syncytia. Soybean cyst nematode (Heterodera glycines) Hg19C07 is a novel effector protein expressed specifically in the dorsal gland cell during nematode parasitism. Here, we describe its ortholog in the beet cyst nematode (Heterodera schachtii), Hs19C07. We demonstrate that Hs19C07 interacts with the Arabidopsis (Arabidopsis thaliana) auxin influx transporter LAX3. LAX3 is expressed in cells overlying lateral root primordia, providing auxin signaling that triggers the expression of cell wall-modifying enzymes, allowing lateral roots to emerge. We found that LAX3 and polygalacturonase, a LAX3-induced cell wall-modifying enzyme, are expressed in the developing syncytium and in cells to be incorporated into the syncytium. We observed no decrease in H. schachtii infectivity in aux1 and lax3 single mutants. However, a decrease was observed in both the aux1lax3 double mutant and the aux1lax1lax2lax3 quadruple mutant. In addition, ectopic expression of 19C07 was found to speed up lateral root emergence. We propose that Hs19C07 most likely increases LAX3-mediated auxin influx and may provide a mechanism for cyst nematodes to modulate auxin flow into root cells, stimulating cell wall hydrolysis for syncytium development.

Dual roles for the variable domain in protein trafficking and host-specific recognition of Heterodera glycines CLE effector proteins

*Soybean cyst nematodes (Heterodera glycines) produce secreted effector proteins that function as peptide mimics of plant CLAVATA3/ESR (CLE)-like peptides probably involved in the developmental reprogramming of root cells to form specialized feeding cells called syncytia. *The site of action and mechanism of delivery of CLE effectors to host plant cells by the nematode, however, have not been established. In this study, immunologic, genetic and biochemical approaches were used to reveal the localization and site of action of H. glycines-secreted CLE proteins in planta. *We present evidence indicating that the nematode CLE propeptides are delivered to the cytoplasm of syncytial cells, but ultimately function in the apoplast, consistent with their proposed role as ligand mimics of plant CLE peptides. We determined that the nematode 12-amino-acid CLE motif peptide is not sufficient for biological activity in vivo, pointing to an important role for sequences upstream of the CLE motif in function. *Genetic and biochemical analysis confirmed the requirement of the variable domain in planta for host-specific recognition and revealed a novel role in trafficking cytoplasmically delivered CLEs to the apoplast in order to function as ligand mimics.

THE EFFECT OF RADIATIONS FROM A MERCURY ARC IN QUARTZ ON ENZYMES : II. THE EFFECT OF ULTRA-VIOLET RADIATION ON AMYLASE IN SOLUTION

Amylase in solution is inactivated by the radiations from a mercury arc in quartz, in a manner similar to that previously reported for pepsin. The reaction was followed to a point where more than 88 per cent change had taken place, the course being that of mono-molecular radiochemical change. Apparently, this reaction is due to the influence of ultra-violet radiation alone.

THE EFFECTS OF RADIATIONS ON BIOLOGICAL SYSTEMS : I. INFLUENCE OF HIGH-FREQUENCY X-RAY RADIATION UPON THE DURATION OF THE PREPUPAL PERIOD OF DROSOPHILAE

The effect of high-frequency x-ray irradiation in prolongation of the larval stage of Drosophila melanogaster has been studied further, and evidence presented of the attainment of a maximum effect followed by a decrease to an almost level plateau in the course curve of average (median) prepupal period (φ) as a function of the period of irradiation (t) under otherwise fixed conditions. The variation of effects of the experimental treatment with age of the larvae at the time of irradiation has been demonstrated in both control and irradiated lots, and a strikingly decreased effect observed when ventilation was not supplied as usual. Means of employment of a living system of this type as an indicator of effectiveness of radiation as in phantom depth or other distributional experiments have been presented and their use illustrated.

Quantitative Detection of Double-Stranded RNA-Mediated Gene Silencing of Parasitism Genes in Heterodera glycines

The introduction of a double-stranded RNA (dsRNA) into an organism to induce sequence-specific RNA interference (RNAi) of a target transcript has become a powerful technique to investigate gene function in nematodes and many organisms. Data provided here indicate that the inclusion of 1-2 mM spermidine and 50 mM octopamine and a 24 hr incubation period of nematodes in double-stranded RNA (dsRNA) soaking solutions resulted in a considerable increase in the percentage of nematodes that ingested dsRNA as compared to previous reports. This modified dsRNA soaking method was coupled with quantitative real-time RT-PCR (qRT-PCR) analyses to assess the potential silencing of the Heterodera glycines parasitism gene transcripts Hg-pel-1 and Hg-4E02 that are expressed within the esophageal gland cells of preparasitic H. glycines J2. The Hg-pel-1 transcript was most efficiently silenced with one dsRNA construct (ds267) at the highest dsRNA soaking concentration of 5.0 mg/ml, while the Hg-4E02 transcript was more efficiently silenced at the 2.5 mg/ml dsRNA concentration as compared to 5.0 mg/ml. A dsRNA construct (ds285) complementary to a different sequence within the Hg-pel-1 transcript than construct ds267 induced only minimal silencing of the Hg-pel-1 transcript at 2.5 mg/ml. The results suggest that both dsRNA concentration and sequence relative to the transcript targeted are critical for maximizing potential RNAi effects in parasitic nematodes.

In planta localization of a beta-1,4-endoglucanase secreted by Heterodera glycines

Polyclonal sera specific to beta-1,4-endoglucanases (cellulases) synthesized in the subventral esophageal gland cells of the soybean cyst nematode, Heterodera glycines, were used to provide the first identification of a nematode esophageal gland protein that is secreted into host plant tissue. Sera generated to proteins encoded by Hg-eng-1 and Hg-eng-2 (endoglucanases) did not cross-react with soybean root proteins on Western blots (immunoblots) or in immunofluorescence microscopy of noninoculated (control) soybean root sections. In cross sections of soybean roots at 24 h after inoculation of roots with second-stage juveniles of H. glycines, HG-ENG-1 was localized within the nematode's subventral gland cells and was not detected in root tissue. HG-ENG-2 was localized within the subventral gland cells and was secreted from the juvenile's stylet into root cortical tissue at 24 h after inoculation of roots with second-stage juveniles of H. glycines. HG-ENG-2 was localized along the juvenile's migratory path through the root cortex.

Dental health related behaviours in toddlers in low and high caries areas in St Helens, north west England

The aim of this investigation was to compare the dental health behaviour of toddlers in low caries (A) and high caries (B) communities in St Helens. Parents of 60 children aged between 17 and 20 months in community A, and 68 in community B were interviewed at home. Using 24-hour dietary recall, sugar intake was recorded as sugar episodes-a sugar episode being a half-hour period during which any amount of non-milk extrinsic sugars (NMES) was consumed. Exposure to fluoride was recorded according to the number of times fluoride toothpaste was used and whether a fluoride supplement was given in the 24-hour period. The median sugar episode score for community A was 6 per 24-hour period (interquartile range 5 to 8), compared with 10.5 (7 to 13) for community B. Sixty per cent of parents in community A compared with 37% in community B reported brushing their child's teeth twice daily with fluoride toothpaste. The respective figures for use of fluoride supplements were 12% and 6%. It is concluded that patterns of dental health behaviour are established early in children's lives, and that marked differences exist between communities within the same district. Recommendations are made for oral health promotion policy.

Industrial atmospheric pollution, historical land use patterns and mortality

BACKGROUND

The measurement of atmospheric pollution for epidemiological studies is problematic. This study presents a new proxy measure of atmospheric pollution of industrial origin and uses it to determine, at electoral ward level, the relationship between atmospheric pollution and all-cause mortality.

METHODS

All-cause Standardized Mortality Ratios (SMR), all ages, and for persons under 65 years for the period 1984-1988, proportions of land in each ward utilized by industrial works (the proxy for atmospheric pollution) and levels of socioeconomic deprivation of the ward residents were compared in 104 electoral wards.

RESULTS

The all-age SMR in the 22 wards containing the largest proportions of industrial land (113) was 9.7 per cent higher than the SMR (103) in the 60 wards with no industrial land. The under 65 years SMR in the 22 highly industrialized wards (120) was 22.4 per cent higher than the SMR (98) in the wards with no industrial land. After matching the levels of deprivation, the all-age SMR in the 15 wards containing over 10 per cent industrial land (116) was significantly higher than the SMR in 15 wards containing no industrial land (108); corresponding figures for the under 65 years SMR were 135 and 118.

CONCLUSIONS

A greater proportion of industrial land in a ward is associated with a higher mortality of the ward residents, even after controlling for the level of socio-economic deprivation of the residents. The association between deprivation and mortality is stronger than the association between atmospheric pollution and mortality. There is an urgent need for better measures of atmospheric pollution which are usable in epidemiological studies.

Clinical guidelines and their implementation

Within the UK there has been increasing interest in the development and implementation of guidelines, as the emphasis on clinical effectiveness is gathering momentum. This paper outlines some of the practical issues encountered in developing and implementing guidelines, based on experiences within Liverpool. Developing local guidelines can be a lengthy process, but that process is not a waste of time if it means there is more likely to be compliance in the end. Dissemination of guidelines alone is not enough; it needs to be combined with an appropriate implementation strategy. There is a danger of primary care being overloaded with new guidelines; there needs to be a timed strategy for their introduction. More imaginative thought needs to be put into the marketing of new ideas in order to change practice. We need to encourage the ethos amongst healthcare professionals of expecting to have to constantly update knowledge and practice.

Public health and economics in tandem: programme budgeting, marginal analysis and priority setting in practice

In the wake of the reforms of the UK National Health Service there has been increased interest in 'getting it right' with respect to priority setting in health care. This article examines the way in which programme budgeting and marginal analysis (PBMA) were introduced into North Mersey. It provides a very practical introduction to the topic and indicates the actual processes that were gone through. It is suggested that, in terms of getting participants in the PBMA exercise to think through what programmes comprise, what they cost, what they are trying to achieve and to focus on relevant possible changes, there was considerable merit in the approach. However there are problems, particularly at the level of determining the costs of different programmes.

A tool to measure the change in health status of selected adult patients before and after intensive care

If the effect of intensive care on the patient is to be fully assessed then the health status of patients before and after admission to ICU must be measured. The validity of a simplified system which can also use relatives, where necessary, as informants on the patients' pre-morbid health status has been evaluated. In a District General Hospital Intensive Care Unit a questionnaire based survey of 85 patients admitted over a period of eight months used a new specially-designed instrument and compared this with the Functional Limitations Profile (FLP) and the Perceived Quality of Life instrument (PQL). Relatives completed the health status questionnaire as soon as possible after the patient's admission and patients completed a suitably modified version at discharge from ICU. Patients were sent the FLP, PQL and modified health status questionnaire six months and one year after discharge. Questionnaires were completed by 59 paired relatives and patients. Questions were answered in the same way by relatives and patients; 42 of the 59 pairs of results were in agreement within two points of better or worse health. The closest responses were provided by wives in daily contact with their partner. At six months post ICU discharge, 49 patients completed the follow-up questionnaires, 12 patients had died and three were too confused to co-operate. Twenty-one patients (25%) were lost to follow-up. At one year post ICU discharge, 43 patients completed the follow-up questionnaires, one other patient had died and three still remained confused.(ABSTRACT TRUNCATED AT 250 WORDS)

Hyponatremia in spinal cord injury

Hypoosmolar hyponatremia (serum Na+ less than 130 mmol/L) has proven a common and incompletely explained phenomenon in the spinal cord injured patient. When present, it has generally been preceded by excessive fluid intake and environmental/dietary factors which reversibly restrict free water excretion. We have attempted to more fully characterize the determinants of SCI-associated hyponatremia by retrospectively analyzing its features and treatment response in a series of 14 hyponatremic SCI patients. In most instances, hyponatremia could be attributed to uncontrolled fluid intake in the presence of an acute or semiacute illness and thus stimuli for non-osmotic releases of arginine vasopressin. Treatment measures generally included administration of 3% saline, with all patients recovering uneventfully from their episode of hyponatremia.

Pyomyositis in spinal cord injury patients

Bacterial infections remain a major cause of morbidity and mortality among patients with longstanding spinal cord injury. Infection may occur in a number of different foci, often taxing the skill of the most accomplished diagnostician. Herein are described three patients with fever of unknown origin wherein extensive diagnostic workups ultimately led to the diagnosis of primary pyomyositis. These patients demonstrate the importance of repeated careful physician examination in determining the site of infection in patients with established sensorimotor deficits. Although primary pyomyositis is not a common occurrence in those with spinal cord injuries, it should be included as a potential cause of fever in this patient population.

THE EFFECTS OF RADIATIONS ON BIOLOGICAL SYSTEMS : II. IMMEDIATE AND SUBSEQUENT EFFECTS OF X-RAY IRRADIATION UPON RESPIRATION OF DROSOPHILA LARVAE

By means of measurement of CO(2) respiratory rates it has been possible to observe immediate and latent effects of x-ray irradiations upon Drosophila larvae. The observations were extended over a period of several days, the duration of the prepupal period being observed also. In every instance a significant decrease in the rate of CO(2) respiration was observed immediately after irradiation. This decrease was univariant with the period of irradiation within the experimental limits.

A VISCOSIMETRIC METHOD OF ESTIMATING ENZYME CONCENTRATION WITH SPECIAL REFERENCE TO AMYLASE

Certain technical modifications of the viscosimetric methods as first employed by Northrop and Hussey have been presented. Most of these have been employed with satisfactory results in the irradiation studies of Hussey and Thompson over a period of several years. These are in turn applied to a method of estimation of amylase concentration.