Molecular detection of Phytophthora pluvialis, the causal agent of red needle cast in Pinus radiata.

BACKGROUND: Phytophthora pluvialis was first described in 2013 and is the causal agent of red needle cast (RNC) in Pinus radiata as well as infection in Douglas fir (Pseudotsuga menziesii). A species-specific PCR is necessary for detection of this pathogen and diagnosis of RNC. OBJECTIVE: To design and validate a species-specific molecular assay for P. pluvialis using isolates from infected pine needles. METHODS: Species-specific PCR primers were generated from the ras-related GTP-binding protein 1 gene (ypt1) gene sequence, concentrating on DNA regions unique to P. pluvialis, and real-time and quantitative polymerase chain reaction (qPCR) were used to detect P. pluvialis from both artificially inoculated and naturally infected samples. RESULTS: The species-specific PCR assay was generated following P. pluvialis DNA sequence analysis. In vitro tests of the specificity of the probe-based, quantitative, polymerase chain reaction (qPCR) assay showed that no amplification was observed with other Phytophthora species including other closely-related clade 3 species, or with fungal species associated with pine or with pine DNA. The limit of detection of the qPCR assay was 2 pg/µl. When the qPCR assay was used to detect P. pluvialis in artificially-inoculated and naturally infected P. radiata needles, a PCR product was detected in all inoculated samples; the mean concentration ranges of P. pluvialis DNA in the inoculated and naturally infected samples tested were 5.9-124.5 pg/µl and 8.1-340.2 pg/µl, respectively. The assays described herein were used with serological diagnostic strips, providing the ability to identify to species level. CONCLUSIONS: The assay described herein detects P. pluvialis with high specificity and sensitivity from a range of DNA samples, including those extracted from infected plant material and serological diagnostic strips. The ability to detect and identify P. pluvialis, from infected tissues directly, provides value and practicality to diagnostics, biosecurity and research.

Genome sequences of six Phytophthora species associated with forests in New Zealand.

In New Zealand there has been a long association of Phytophthora diseases in forests, nurseries, remnant plantings and horticultural crops. However, new Phytophthora diseases of trees have recently emerged. Genome sequencing has been performed for 12 Phytophthora isolates, from six species: Phytophthora pluvialis, Phytophthora kernoviae, Phytophthora cinnamomi, Phytophthora agathidicida, Phytophthora multivora and Phytophthora taxon Totara. These sequences will enable comparative analyses to identify potential virulence strategies and ultimately facilitate better control strategies. This Whole Genome Shotgun data have been deposited in DDBJ/ENA/GenBank under the accession numbers LGTT00000000, LGTU00000000, JPWV00000000, JPWU00000000, LGSK00000000, LGSJ00000000, LGTR00000000, LGTS00000000, LGSM00000000, LGSL00000000, LGSO00000000, and LGSN00000000.

Reduced seizure threshold and altered network oscillatory properties in a mouse model of Rett syndrome.

Rett syndrome (RTT) is a disorder with a pronounced neurological phenotype and is caused mainly by mutations in the X-linked gene MECP2. A common feature of RTT is an abnormal electroencephalography and a propensity for seizures. In the current study we aimed to assess brain network excitability and seizure propensity in a mouse model of RTT. Mice in which Mecp2 expression was silenced (Mecp2(stop/y)) showed a higher seizure score (mean=6 ± 0.8 compared to 4±0.2 in wild-type [WT]) and more rapid seizure onset (median onset=10 min in Mecp2(stop/y) and 32 min in WT) when challenged with the convulsant drug kainic acid (25mg/kg). Hippocampal slices from Mecp2(stop/y) brain displayed no spontaneous field potential activities under control conditions but showed higher power gamma frequency field potential oscillations compared to WT in response to kainic acid (400 nM) in vitro. Brain slices challenged with the GABA(A)-receptor antagonist bicuculline (0.1-10 µM) and the potassium channel blocker 4-aminopyridine (1-50 µM) also revealed differences between genotypes with hippocampal circuits from Mecp2(stop/y) mouse slices showing enhanced epileptiform burst duration and frequency. In contrast to these network level findings, single cell analysis of pyramidal cells by whole-cell patch clamp recording revealed no detectable differences in synaptic or biophysical properties between methyl-CpG-binding protein 2 (MeCP2)-containing and MeCP2-deficient neurons. These data support the proposal that loss of MeCP2 alters network level excitability in the brain to promote epileptogenesis.

The Barrett-Lennard Relationship Inventory (BLRI): current and potential uses with family systems.

The search for and measurement of important relationship qualities have always been of interest to family therapists. Within a Rogerian perspective, empathy, regard, and congruence are believed to be among the most important indicators of the quality of human relationships. These variables, or conceptually similar ones, are also important in several current models of family functioning. Barrett-Lennard (1,2) developed an instrument, the Barrett-Lennard Relationship Inventory (BLRI), to measure empathy, regard, and congruence. Although the major use of the BLRI has been in psychotherapy outcome research (13), several studies have shown that it is a sensitive indicator of marital satisfaction and of changes occurring in marital-improvement programs. The present study is a factor analysis of the BLRI based on data from 345 women who rated levels of empathy, regard, and congruence in their relationship with their husbands. The results robustly confirm the three-factor structure of the BLRI in what is believed to be the first factor analysis in the context of a family member rating a relationship within the family. The replication of the BLRI's structure in a new relationship context suggests that the dimensions tapped by the BLRI may have some generality and warrant further exploration in a family-systems context. Several advantages of the BLRI over other currently available instruments are discussed, as are potential uses of the BLRI in systems research beyond the marital unit.

Epistemology, family patterns, and psychosomatics: the case of obesity.

A family systems model of obesity is developed that attempts to integrate systems epistemology, Minuchin's work on psychosomatic disorders, and a review of the literature on obesity. The model presents obesity as being inextricably embedded in relationship patterns that fundamentally influence its etiology and maintenance. It is argued that the emergent properties of these relationships need to be the focus of analysis, rather than the elementary components residing within the individual, which are emphasized in traditional theories of obesity. The radical shift involved in moving from the traditional mechanistic models to a systems perspective is also discussed because these approaches are based on different epistemologies. The fundamental differences between these epistemologies are important and often underemphasized, which has led to much confusion in past research. Based on the model developed here and supportive data from the obesity literature, the conclusion is reached that obesity research and treatment are likely to be advanced by adopting a systemic approach.