Declining muscle NAD+ in a hyperandrogenism PCOS mouse model: Possible role in metabolic dysregulation

Polycystic ovary syndrome (PCOS) is a common endocrine disorder, defined by reproductive and endocrine abnormalities, with metabolic dysregulation including obesity, insulin resistance and hepatic steatosis. Recently, it was found that skeletal muscle insulin sensitivity could be improved in obese, post-menopausal, pre-diabetic women through treatment with nicotinamide mononucleotide (NMN), a precursor to the prominent redox cofactor nicotinamide adenine dinucleotide (NAD⁺). Given that PCOS patients have a similar endocrine profile to these patients, we hypothesised that declining NAD levels in muscle might play a role in the pathogenesis of the metabolic syndrome associated with PCOS, and that this could be normalized through NMN treatment. Here, we tested the impact of NMN treatment on the metabolic syndrome of the dihydrotestosterone (DHT) induced mouse model of PCOS. We observed lower NAD levels in the muscle of PCOS mice, which was normalized by NMN treatment. PCOS mice were hyperinsulinaemic, resulting in increased adiposity and hepatic lipid deposition. Strikingly, NMN treatment completely normalized these aspects of metabolic dysfunction. We propose that addressing the decline in skeletal muscle NAD levels associated with PCOS can normalize insulin sensitivity, preventing compensatory hyperinsulinaemia, which drives obesity and hepatic lipid deposition, though we cannot discount an impact of NMN on other tissues to mediate these effects. These findings support further investigation into NMN treatment as a new therapy for normalizing the aberrant metabolic features of PCOS.

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Polycystic ovarian syndrome (PCOS) leads to declining NAD⁺ levels in skeletal muscle tissue.

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Declining NAD⁺ in muscle can be rescued by treating with the metabolic precursor nicotinamide mononucleotide (NMN).

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NMN treatment corrects compensatory hyperinsulinemia in a mouse model of PCOS.

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Reductions in circulating insulin levels from NMN treatment moderates adipose expansion and hepatic lipid deposition.

Androgen signaling in adipose tissue, but less likely skeletal muscle, mediates development of metabolic traits in a PCOS mouse model

Polycystic ovary syndrome (PCOS) is a common, multifactorial disorder characterized by endocrine, reproductive, and metabolic dysfunction. As the etiology of PCOS is unknown, there is no cure and symptom-oriented treatments are suboptimal. Hyperandrogenism is a key diagnostic trait, and evidence suggests that androgen receptor (AR)-mediated actions are critical to PCOS pathogenesis. However, the key AR target sites involved remain to be fully defined. Adipocyte and muscle dysfunction are proposed as important sites involved in the manifestation of PCOS traits. We investigated the role of AR signaling in white adipose tissue (WAT), brown adipose tissue (BAT), and skeletal muscle in the development of PCOS in a hyperandrogenic PCOS mouse model. As expected, dihydrotestosterone (DHT) exposure induced key reproductive and metabolic PCOS traits in wild-type (WT) females. Transplantation of AR-insensitive (AR^-/-) WAT or BAT from AR knockout females (ARKO) into DHT-treated WT mice ameliorated some metabolic PCOS features, including increased body weight, adiposity, and adipocyte hypertrophy, but not reproductive PCOS traits. In contrast, DHT-treated ARKO female mice transplanted with AR-responsive (AR^+/+) WAT or BAT continued to resist developing PCOS traits. DHT-treated skeletal muscle-specific AR knockout females (SkMARKO) displayed a comparable phenotype with that of DHT-treated WT females, with full development of PCOS traits. Taken together, these findings infer that both WAT and BAT, but less likely skeletal muscle, are key sites of AR-mediated actions involved in the experimental pathogenesis of metabolic PCOS traits. These data further support targeting adipocyte AR-driven pathways in future research aimed at developing novel therapeutic interventions for PCOS.NEW & NOTEWORTHY Hyperandrogenism is a key feature in the pathogenesis of polycystic ovary syndrome (PCOS); however, the tissue sites of androgen receptor (AR) signaling are unclear. In this study, AR signaling in white and brown adipose tissue, but less likely in skeletal muscle, was found to be involved in the development of metabolic PCOS traits, highlighting the importance of androgen actions in adipose tissue and obesity in the manifestation of metabolic disturbances.

The interplay between PCOS pathology and diet on gut microbiota in a mouse model

The gut microbiome has been implicated in polycystic ovary syndrome (PCOS) pathophysiology. PCOS is a disorder with reproductive, endocrine and metabolic irregularities, and several studies report that PCOS is associated with a decrease in microbial diversity and composition. Diet is an important regulator of the gut microbiome, as alterations in macronutrient composition impact the balance of gut microbial communities. This study investigated the interplay between macronutrient balance and PCOS on the gut microbiome of control and dihydrotestosterone (DHT)-induced PCOS-like mice exposed to diets that varied in protein (P), carbohydrate (C) and fat (F) content. The amount of dietary P, C and F consumed significantly altered alpha (α) and beta (β) diversity of the gut microbiota of control and PCOS-like mice. However, α-diversity between control and PCOS-like mice on the same diet did not differ significantly. In contrast, β-diversity was significantly altered by PCOS pathology. Further analysis identified an operational taxonomic unit (OTU) within Bacteroides (OTU3) with 99.2% similarity to Bacteroides acidifaciens, which is inversely associated with obesity, to be significantly decreased in PCOS-like mice. Additionally, this study investigated the role of the gut microbiome in the development of PCOS traits, whereby PCOS-like mice were transplanted with healthy fecal microbiota from control mice. Although the PCOS gut microbiome shifted toward that of control mice, PCOS traits were not ameliorated. Overall, these findings demonstrate that while diet exerts a stronger influence over gut microbiota diversity than PCOS pathology, overall gut microbiota composition is affected by PCOS pathology.

Pathogenesis of Reproductive and Metabolic PCOS Traits in a Mouse Model

Polycystic ovary syndrome (PCOS) is a common and heterogeneous disorder; however, the etiology and pathogenesis of PCOS are poorly understood and current management is symptom-based. Defining the pathogenesis of PCOS traits is important for developing early PCOS detection markers and new treatment strategies. Hyperandrogenism is a defining characteristic of PCOS, and studies support a role for androgen-driven actions in the development of PCOS. Therefore, we aimed to determine the temporal pattern of development of PCOS features in a well-characterized dihydrotestosterone (DHT)-induced PCOS mouse model after 2, 4, and 8 weeks of DHT exposure. Following 2 weeks of treatment, DHT induced the key PCOS reproductive features of acyclicity, anovulation, and multifollicular ovaries as well as a decrease in large antral follicle health. DHT-treated mice displayed the metabolic PCOS characteristics of increased body weight and exhibited increased visceral adiposity after 8 weeks of DHT treatment. DHT treatment also led to an increase in circulating cholesterol after 2 weeks of exposure and had an overall effect on fasting glucose levels, but not triglycerides, aspartate transaminase (AST) and alanine transaminase (ALT) levels, or hepatic steatosis. These data reveal that in this experimental PCOS mouse model, acyclicity, anovulation, and increased body weight are early features of a developing PCOS phenotype whereas adiposity, impaired glucose tolerance, dyslipidemia, and hepatic steatosis are later developing features of PCOS. These findings provide insights into the likely sequence of PCOS trait development and support the addition of body weight criteria to the early diagnosis of PCOS.

Metabolic PCOS Features Are Ameliorated by Mitochondrial Uncoupler BAM15 in a PCOS Mouse Model

Polycystic ovary syndrome (PCOS) is a prevalent endocrine condition characterized by endocrine, reproductive and metabolic dysfunction. At present, there is no cure for PCOS and current treatments are suboptimal. Obesity and adverse metabolic features are prevalent in women with PCOS, with weight loss having a beneficial effect on PCOS features. The use of dietary interventions aimed at weight loss have low long-term compliance in women suffering from PCOS. Recent data from animal studies has shown that a small molecule mitochondrial uncoupler, BAM15, is an effective method to pharmacologically treat obesity and metabolic diseases. Therefore, the aim of this study was to investigate the efficacy of BAM15 to ameliorate PCOS-traits in a hyperandrogenic PCOS mouse model. As expected, exposure of female mice to dihydrotestosterone (DHT) induced the PCOS metabolic features of increased body weight (P<0.05), lean mass (P<0.001), increased parametrial and mesenteric fat pad weights (both P<0.05) and adipocyte hypertrophy (P<0.05). Additionally, DHT-induced PCOS mice exhibited insulin resistance measured by HOMA-IR, increased cholesterol and fasting triglyceride levels and hepatic steatosis (all P<0.05). In contrast, DHT-induced PCOS females treated with BAM15 displayed body weights which were comparable with controls, a significant decrease in parametrial and mesenteric fat depot weights (P<0.05) and reduced adipocyte hypertrophy. Furthermore, BAM15 treatment decreased insulin resistance, cholesterol and fasting triglyceride levels, as well as the degree of hepatic steatosis observed in PCOS females, to levels comparable with controls. PCOS mice presented the reproductive PCOS traits of irregular cycles and ovulatory dysfunction, however BAM15 did not improve these PCOS traits. These findings demonstrate that the pharmacologic mitochondrial uncoupler BAM15 is able to ameliorate metabolic PCOS features in a hyperandrogenic PCOS mouse model. These data provide compelling evidence to support BAM15 as a potential innovative and viable therapeutic approach to manage metabolic traits associated with PCOS.

Neurokinin 3 Receptor Antagonism Ameliorates Key Metabolic Features in a Hyperandrogenic PCOS Mouse Model

Polycystic ovary syndrome (PCOS) is a prevalent endocrine condition characterized by a range of endocrine, reproductive, and metabolic abnormalities. At present, management of women with PCOS is suboptimal as treatment is only symptomatic. Clinical and experimental advances in our understanding of PCOS etiology support a pivotal role for androgen neuroendocrine actions in PCOS pathogenesis. Hyperandrogenism is a key PCOS trait and androgen actions play a role in regulating the kisspeptin-/neurokinin B-/dynorphin (KNDy) system. This study aimed to investigate if targeted antagonism of neurokinin B signaling through the neurokinin 3 receptor (NK3R) would reverse PCOS traits in a dihydrotestosterone (DHT)-induced mouse model of PCOS. After 3 months, DHT exposure induced key reproductive PCOS traits of cycle irregularity and ovulatory dysfunction, and PCOS-like metabolic traits including increased body weight; white and brown fat pad weights; fasting serum triglyceride and glucose levels, and blood glucose incremental area under the curve. Treatment with a NK3R antagonist (MLE4901) did not impact the observed reproductive defects. In contrast, following NK3R antagonist treatment, PCOS-like females displayed decreased total body weight, adiposity, and adipocyte hypertrophy, but increased respiratory exchange ratio, suggesting NK3R antagonism altered the metabolic status of the PCOS-like females. NK3R antagonism did not improve circulating serum triglyceride or fasted glucose levels. Collectively, these findings demonstrate that NK3R antagonism may be beneficial in the treatment of adverse metabolic features associated with PCOS and support neuroendocrine targeting in the development of novel therapeutic strategies for PCOS.

Impact of nicotinamide mononucleotide on transplanted mouse ovarian tissue

Ovarian tissue cryopreservation and future transplantation is the only strategy to preserve the fertility of young female adolescent and prepubertal patients. The primary challenge to ovarian graft longevity is the substantial loss of primordial follicles during the period of ischaemia post-transplantation. Nicotinamide mononucleotide (NMN), a precursor of the essential metabolite NAD+, is known to reduce ischaemic damage. Therefore, the objective of the current study was to assess the impact of short- and long-term NMN administration on follicle number and health following ovarian tissue transplantation. Hemi-ovaries from C57Bl6 mice (n = 8-12/group) were transplanted under the kidney capsule of bilaterally ovariectomised severe combined immunodeficient (SCID) mice. Recipient mice were administered either normal drinking water or water supplemented with NMN (2 g/L) for either 14 or 56 days. At the end of each treatment period, ovarian transplants were collected. There was no effect of NMN on the resumption of oestrous or length of oestrous cycles. Transplantation significantly reduced the total number of follicles with the greatest impact observed at the primordial follicle stage. We report that NMN did not prevent this loss. While NMN did not significantly impact the proportion of apoptotic follicles, NMN normalised PCNA expression at the primordial and intermediate stages but not at later stages. In conclusion, NMN administration did not prevent ovarian follicle loss under the conditions of this study.

Defining the impact of dietary macronutrient balance on PCOS traits

Lifestyle, mainly dietary, interventions are first-line treatment for women with polycystic ovary syndrome (PCOS), but the optimal diet remains undefined. We combined a hyperandrogenized PCOS mouse model with a systematic macronutrient approach, to elucidate the impact of dietary macronutrients on the development of PCOS. We identify that an optimum dietary macronutrient balance of a low protein, medium carbohydrate and fat diet can ameliorate key PCOS reproductive traits. However, PCOS mice display a hindered ability for their metabolic system to respond to diet variations, and varying macronutrient balance did not have a beneficial effect on the development of metabolic PCOS traits. We reveal that PCOS traits in a hyperandrogenic PCOS mouse model are ameliorated selectively by diet, with reproductive traits displaying greater sensitivity than metabolic traits to dietary macronutrient balance. Hence, providing evidence to support the development of evidence-based dietary interventions as a promising strategy for the treatment of PCOS, especially reproductive traits.

Androgen Action in Adipose Tissue and the Brain are Key Mediators in the Development of PCOS Traits in a Mouse Model

Polycystic ovary syndrome (PCOS) is a complex disorder characterized by endocrine, reproductive, and metabolic abnormalities. Despite PCOS being the most common endocrinopathy affecting women of reproductive age, the etiology of PCOS is poorly understood, so there is no cure and symptomatic treatment is suboptimal. Hyperandrogenism is the most consistent feature observed in PCOS patients, and recently aberrant neuroendocrine signaling and adipose tissue function have been proposed as playing a role in the development of PCOS. To investigate the role of adipose tissue and the brain as key sites for androgen receptor (AR)-mediated development of PCOS, we combined a white and brown adipose and brain-specific AR knockout (AdBARKO) mouse model with a dihydrotestosterone (DHT)-induced mouse model of PCOS. As expected, in wildtype (WT) control females, DHT exposure induced the reproductive PCOS traits of cycle irregularity, ovulatory dysfunction, and reduced follicle health, whereas in AdBARKO females, DHT did not produce the reproductive features of PCOS. The metabolic PCOS characteristics of increased adiposity, adipocyte hypertrophy, and hepatic steatosis induced by DHT in WT females were not evident in DHT-treated AdBARKO females, which displayed normal white adipose tissue weight and no adipocyte hypertrophy or liver steatosis. Dihydrotestosterone treatment induced increased fasting glucose levels in both WT and AdBARKO females. These findings demonstrate that adipose tissue and the brain are key loci of androgen-mediated actions involved in the developmental origins of PCOS. These data support targeting adipocyte and neuroendocrine AR-driven pathways in the future development of novel therapeutic strategies for PCOS.

Androgen signaling pathways driving reproductive and metabolic phenotypes in a PCOS mouse model

As the mechanistic basis of polycystic ovary syndrome (PCOS) remains unknown, current management relies on symptomatic treatment. Hyperandrogenism is a major PCOS characteristic and evidence supports it playing a key role in PCOS pathogenesis. Classically, androgens can act directly through the androgen receptor (AR) or, indirectly, following aromatization, via the estrogen receptor (ER). We investigated the mechanism of androgenic actions driving PCOS by comparing the capacity of non-aromatizable dihydrotestosterone (DHT) and aromatizable testosterone to induce PCOS traits in WT and Ar-knockout (ARKO) mice. DHT and testosterone induced the reproductive PCOS-like features of acyclicity and anovulation in WT females. In ARKO mice, DHT did not cause reproductive dysfunction; however, testosterone treatment induced irregular cycles and ovulatory disruption. These findings indicate that direct AR actions and indirect, likely ER, actions of androgens are important mediators of PCOS reproductive traits. DHT, but not testosterone, induced an increase in body weight, body fat, serum cholesterol and adipocyte hypertrophy in WT mice, but neither androgen induced these metabolic features in ARKO mice. These data infer that direct AR-driven mechanisms are key in driving the development of PCOS metabolic traits. Overall, these findings demonstrate that differing PCOS traits can be mediated via different steroid signaling pathways and indicate that a phenotype-based treatment approach would ensure effective targeting of the underlying mechanisms.

MON-022 Dissecting the Interplay Between Diet and PCOS Pathology on Gut Microbiota in a PCOS Mouse Model

The gut microbiome has been implicated in the development of metabolic disorders such as obesity and type-2 diabetes, and more recently polycystic ovary syndrome (PCOS). PCOS is a heterogeneous disorder with reproductive, endocrine and metabolic irregularities, and clinical and animal studies have reported that PCOS causes a decrease in microbial diversity and composition. Diet is an important regulator of the gut microbiome, and a recent study identified that alterations in macronutrient balance impact gut microbial communities which correlate with different metabolic health outcomes (1). We have identified that macronutrient balance impacts the development of PCOS traits. Therefore, to investigate the interplay between macronutrient balance and a PCOS environment on the gut microbiome, we analyzed the intestinal microbiome from fecal pellets of control and DHT-induced PCOS mice exposed to 10 different diets that varied systematically in protein (P), carbohydrate (C) and fat (F) content. The amount of dietary P, C and F consumed significantly altered alpha and beta diversity of the gut microbiota of pooled control and PCOS mice (P<0.0001). Alpha diversity between control and PCOS mice on the same diet did not differ significantly, and hence was only affected by diet composition. However, beta diversity was significantly altered between control and PCOS mice (P<0.05). We performed DESeq2 analysis and identified an operational taxonomic unit (OTU) within Bacteroides (OTU3) to be the most differentially abundant OTU between control and PCOS mice, with a significant decrease in PCOS mice compared to controls (control: 7.88 and PCOS: 5.38; fold change = 1.464; P<0.0001). The consensus sequence of Bacteroides OTU3 was found to share 99.2% similarity to Bacteroides acidifaciens. B. acidifaciens is associated with obesity with elevated levels reported to prevent the onset of obesity (2). Thus, we then investigated the influence of P, C and F on the relative abundance of Bacteroides OTU3 and revealed an association with C consumption, with increasing levels of C leading to increased levels of Bacteroides OTU3 (Carb: r= 0.22, p=0.0028, q=0.015). These findings demonstrate that diet exerts a stronger influence over the gut microbiome than PCOS pathology. However, the hyperandrogenic PCOS environment does lead to changes in gut microbiota beta diversity, with a specific decrease in an obesity-associated (2) Bacteroides species in PCOS mice that is also responsive to levels of C consumption. Reference: (1) Holmes et al., Cell Metabolism. 2017; 25(1): 140-151. (2) Yang et al., Mucosal Immunology. 2017, 10 (1), 104-116.

SAT-018 Androgen Actions in Adipose Tissue and the Brain Are Key Mediators in the Development of Polycystic Ovary Syndrome

Polycystic ovary syndrome (PCOS) is a complex disorder characterised by endocrine, reproductive and metabolic abnormalities. Despite PCOS being the most common endocrinopathy affecting women of reproductive age, its etiology is poorly understood so there is no cure and symptom-oriented treatment is suboptimal. Elucidation of the underlying mechanisms involved in the pathogenesis of PCOS would pave the way for the development of new interventions for PCOS. Hyperandrogenism is the most consistent feature observed in PCOS patients, and recently aberrant neuroendocrine signalling and adipose tissue function have been proposed as playing a pathogenic role in the development of experimental PCOS. To investigate the role of adipose tissue and the brain as potential key sites for androgen receptor (AR)-mediated development of PCOS, we combined an adipocyte and brain-specific ARKO knockout (AdBARKO) mouse model with a dihydrotestosterone (DHT)-induced mouse model of PCOS. Wildtype (WT) and AdBARKO prepubertal mice were implanted with a blank or DHT implant and examined after 12 weeks. In WT control females, DHT exposure induced the PCOS reproductive traits of cycle irregularity, ovulatory dysfunction and reduced follicle health. In contrast, these reproductive features of PCOS were absent in DHT-treated AdBARKO females. The PCOS metabolic characteristics of increased adiposity, adipocyte hypertrophy and hepatic steatosis were induced by DHT in WT females. Despite DHT treatment, AdBARKO females displayed normal white adipose tissue weight, and adipocyte hypertrophy and hepatic steatosis were not evident. However, as with WT mice, DHT treatment induced increased fasting glucose levels in AdBARKO females. These results demonstrate that adipose tissue and the brain are key loci for androgen-mediated actions involved in the developmental origins of PCOS. These findings support targeting adipocyte and neuroendocrine AR-driven pathways in the future development of novel therapeutic strategies for PCOS.

Tests of General Relativity with GW170817

The recent discovery by Advanced LIGO and Advanced Virgo of a gravitational wave signal from a binary neutron star inspiral has enabled tests of general relativity (GR) with this new type of source. This source, for the first time, permits tests of strong-field dynamics of compact binaries in the presence of matter. In this Letter, we place constraints on the dipole radiation and possible deviations from GR in the post-Newtonian coefficients that govern the inspiral regime. Bounds on modified dispersion of gravitational waves are obtained; in combination with information from the observed electromagnetic counterpart we can also constrain effects due to large extra dimensions. Finally, the polarization content of the gravitational wave signal is studied. The results of all tests performed here show good agreement with GR.

Constraining the p-Mode-g-Mode Tidal Instability with GW170817

We analyze the impact of a proposed tidal instability coupling p modes and g modes within neutron stars on GW170817. This nonresonant instability transfers energy from the orbit of the binary to internal modes of the stars, accelerating the gravitational-wave driven inspiral. We model the impact of this instability on the phasing of the gravitational wave signal using three parameters per star: an overall amplitude, a saturation frequency, and a spectral index. Incorporating these additional parameters, we compute the Bayes factor (lnB_{!pg}^{pg}) comparing our p-g model to a standard one. We find that the observed signal is consistent with waveform models that neglect p-g effects, with lnB_{!pg}^{pg}=0.03_{-0.58}^{+0.70} (maximum a posteriori and 90% credible region). By injecting simulated signals that do not include p-g effects and recovering them with the p-g model, we show that there is a ≃50% probability of obtaining similar lnB_{!pg}^{pg} even when p-g effects are absent. We find that the p-g amplitude for 1.4  M_{⊙} neutron stars is constrained to less than a few tenths of the theoretical maximum, with maxima a posteriori near one-tenth this maximum and p-g saturation frequency ∼70  Hz. This suggests that there are less than a few hundred excited modes, assuming they all saturate by wave breaking. For comparison, theoretical upper bounds suggest ≲10^{3} modes saturate by wave breaking. Thus, the measured constraints only rule out extreme values of the p-g parameters. They also imply that the instability dissipates ≲10^{51}  erg over the entire inspiral, i.e., less than a few percent of the energy radiated as gravitational waves.

Search for Subsolar-Mass Ultracompact Binaries in Advanced LIGO's First Observing Run

We present the first Advanced LIGO and Advanced Virgo search for ultracompact binary systems with component masses between 0.2  M_{⊙}-1.0  M_{⊙} using data taken between September 12, 2015 and January 19, 2016. We find no viable gravitational wave candidates. Our null result constrains the coalescence rate of monochromatic (delta function) distributions of nonspinning (0.2  M_{⊙}, 0.2  M_{⊙}) ultracompact binaries to be less than 1.0×10^{6}  Gpc^{-3}  yr^{-1} and the coalescence rate of a similar distribution of (1.0  M_{⊙}, 1.0  M_{⊙}) ultracompact binaries to be less than 1.9×10^{4}  Gpc^{-3}  yr^{-1} (at 90% confidence). Neither black holes nor neutron stars are expected to form below ∼1  M_{⊙} through conventional stellar evolution, though it has been proposed that similarly low mass black holes could be formed primordially through density fluctuations in the early Universe and contribute to the dark matter density. The interpretation of our constraints in the primordial black hole dark matter paradigm is highly model dependent; however, under a particular primordial black hole binary formation scenario we constrain monochromatic primordial black hole populations of 0.2  M_{⊙} to be less than 33% of the total dark matter density and monochromatic populations of 1.0  M_{⊙} to be less than 5% of the dark matter density. The latter strengthens the presently placed bounds from microlensing surveys of massive compact halo objects (MACHOs) provided by the MACHO and EROS Collaborations.

Steroid profiles by liquid chromatography-mass spectrometry of matched serum and single dominant ovarian follicular fluid from women undergoing IVF

RESEARCH QUESTION

Can IVF outcomes be predicted from the steroid profile generated by liquid chromatography-mass spectrometry (LC-MS/MS) from follicular fluid collected from a single dominant follicle and serum after ovarian stimulation.

DESIGN

Prospective observational cohort study in which serum and follicular fluid were collected from women and used to generate steroid profiles by LC-MS/MS. A total of 93 consecutive women enrolled for IVF treatment were recruited at the Fertility Unit, Royal Prince Alfred Women and Babies Hospital, Sydney between September 2014 and July 2015. Baseline and serum levels at oocyte retrieval, as well as follicular fluid samples from the largest single antral follicle, were collected. All samples underwent steroid analysis within a single batch to measure progesterone (P4), oestradiol (E2), oestrone (E1), dehydroepiandrosterone (DHEA), androstenedione (A4), testosterone (T), dihydrotestosterone (DHT), and 3 α, 5α androstanediol (3α-diol) and 3β, 5α androstanediol (3β-diol).

RESULTS

P4, E2, E1, A4, T, DHEA and A4 were detectable in all baseline serum levels, at oocyte retrieval and in follicular fluid samples, whereas DHT, 3α-diol and 3β-diol were only detectable in a minority of samples. The most consistent predictor of pre-transfer (number of follicles >14mm in diameter, oocytes retrieved or fertilized, day-5 blastocysts) outcomes was baseline serum anti-Müllerian hormone. In follicular fluid, E2 was a negative predictor of the number of oocytes retrieved and the number of day-5 blastocysts but no follicular fluid steroids predicted pregnancy outcome.

CONCLUSIONS

None of the nine steroids measured in follicular fluid predicted pregnancy outcome in women undergoing IVF.

GW170817: Measurements of Neutron Star Radii and Equation of State

On 17 August 2017, the LIGO and Virgo observatories made the first direct detection of gravitational waves from the coalescence of a neutron star binary system. The detection of this gravitational-wave signal, GW170817, offers a novel opportunity to directly probe the properties of matter at the extreme conditions found in the interior of these stars. The initial, minimal-assumption analysis of the LIGO and Virgo data placed constraints on the tidal effects of the coalescing bodies, which were then translated to constraints on neutron star radii. Here, we expand upon previous analyses by working under the hypothesis that both bodies were neutron stars that are described by the same equation of state and have spins within the range observed in Galactic binary neutron stars. Our analysis employs two methods: the use of equation-of-state-insensitive relations between various macroscopic properties of the neutron stars and the use of an efficient parametrization of the defining function p(ρ) of the equation of state itself. From the LIGO and Virgo data alone and the first method, we measure the two neutron star radii as R_{1}=10.8_{-1.7}^{+2.0}  km for the heavier star and R_{2}=10.7_{-1.5}^{+2.1}  km for the lighter star at the 90% credible level. If we additionally require that the equation of state supports neutron stars with masses larger than 1.97  M_{⊙} as required from electromagnetic observations and employ the equation-of-state parametrization, we further constrain R_{1}=11.9_{-1.4}^{+1.4}  km and R_{2}=11.9_{-1.4}^{+1.4}  km at the 90% credible level. Finally, we obtain constraints on p(ρ) at supranuclear densities, with pressure at twice nuclear saturation density measured at 3.5_{-1.7}^{+2.7}×10^{34}  dyn cm^{-2} at the 90% level.

Search for Tensor, Vector, and Scalar Polarizations in the Stochastic Gravitational-Wave Background

The detection of gravitational waves with Advanced LIGO and Advanced Virgo has enabled novel tests of general relativity, including direct study of the polarization of gravitational waves. While general relativity allows for only two tensor gravitational-wave polarizations, general metric theories can additionally predict two vector and two scalar polarizations. The polarization of gravitational waves is encoded in the spectral shape of the stochastic gravitational-wave background, formed by the superposition of cosmological and individually unresolved astrophysical sources. Using data recorded by Advanced LIGO during its first observing run, we search for a stochastic background of generically polarized gravitational waves. We find no evidence for a background of any polarization, and place the first direct bounds on the contributions of vector and scalar polarizations to the stochastic background. Under log-uniform priors for the energy in each polarization, we limit the energy densities of tensor, vector, and scalar modes at 95% credibility to Ω_{0}^{T}<5.58×10^{-8}, Ω_{0}^{V}<6.35×10^{-8}, and Ω_{0}^{S}<1.08×10^{-7} at a reference frequency f_{0}=25  Hz.

GW170817: Implications for the Stochastic Gravitational-Wave Background from Compact Binary Coalescences

The LIGO Scientific and Virgo Collaborations have announced the event GW170817, the first detection of gravitational waves from the coalescence of two neutron stars. The merger rate of binary neutron stars estimated from this event suggests that distant, unresolvable binary neutron stars create a significant astrophysical stochastic gravitational-wave background. The binary neutron star component will add to the contribution from binary black holes, increasing the amplitude of the total astrophysical background relative to previous expectations. In the Advanced LIGO-Virgo frequency band most sensitive to stochastic backgrounds (near 25 Hz), we predict a total astrophysical background with amplitude Ω_{GW}(f=25  Hz)=1.8_{-1.3}^{+2.7}×10^{-9} with 90% confidence, compared with Ω_{GW}(f=25  Hz)=1.1_{-0.7}^{+1.2}×10^{-9} from binary black holes alone. Assuming the most probable rate for compact binary mergers, we find that the total background may be detectable with a signal-to-noise-ratio of 3 after 40 months of total observation time, based on the expected timeline for Advanced LIGO and Virgo to reach their design sensitivity.

First Search for Nontensorial Gravitational Waves from Known Pulsars

We present results from the first directed search for nontensorial gravitational waves. While general relativity allows for tensorial (plus and cross) modes only, a generic metric theory may, in principle, predict waves with up to six different polarizations. This analysis is sensitive to continuous signals of scalar, vector, or tensor polarizations, and does not rely on any specific theory of gravity. After searching data from the first observation run of the advanced LIGO detectors for signals at twice the rotational frequency of 200 known pulsars, we find no evidence of gravitational waves of any polarization. We report the first upper limits for scalar and vector strains, finding values comparable in magnitude to previously published limits for tensor strain. Our results may be translated into constraints on specific alternative theories of gravity.

The Role of Central Androgen Receptor Actions in Regulating the Hypothalamic-Pituitary-Ovarian Axis

The androgen receptor (AR) is expressed throughout the hypothalamic-pituitary-gonadal (HPG) axis, and findings from female global AR knockout mice confirm that AR-mediated androgen actions play important roles in regulating female reproductive function. We generated neuron-specific AR knockout mice (NeurARKO) to investigate the functional role of neuronal AR-mediated androgen action in regulating the female HPG axis and fertility. Relative to control females, NeurARKO females exhibited elevated luteinizing hormone (LH) levels at diestrus (p < 0.05) and a compromised serum LH response to ovariectomy and E2 priming (p < 0.01). Furthermore, NeurARKO females displayed reduced Kiss1 mRNA expression in the anteroventral periventricular nucleus at diestrus (p < 0.05) and proestrus (p < 0.05), but elevated Kiss1 (p < 0.05) and neurokinin B (Tac2, p < 0.05) mRNA expression in the arcuate nucleus at proestrus compared to WT controls. Ovarian follicle dynamics were also altered in NeurARKO ovaries at 3 months of age, with a significant reduction in large antral follicle numbers at the proestrus stage compared to control WT ovaries (p < 0.05). Increased follicular atresia was evident in NeurARKO ovaries with a 4-fold increase in unhealthy large preantral follicles (p < 0.01). Despite the findings of aberrant neuroendocrine and ovarian characteristics in the NeurARKO females, estrous cyclicity and overall fertility were comparable between NeurARKO and WT females. In conclusion, our findings revealed that selective loss of neuronal AR actions impacts the kisspeptin/GnRH/LH cascade leading to compromised ovarian follicle dynamics.

GW170817: Observation of Gravitational Waves from a Binary Neutron Star Inspiral

On August 17, 2017 at 12∶41:04 UTC the Advanced LIGO and Advanced Virgo gravitational-wave detectors made their first observation of a binary neutron star inspiral. The signal, GW170817, was detected with a combined signal-to-noise ratio of 32.4 and a false-alarm-rate estimate of less than one per 8.0×10^{4}  years. We infer the component masses of the binary to be between 0.86 and 2.26  M_{⊙}, in agreement with masses of known neutron stars. Restricting the component spins to the range inferred in binary neutron stars, we find the component masses to be in the range 1.17-1.60  M_{⊙}, with the total mass of the system 2.74_{-0.01}^{+0.04}M_{⊙}. The source was localized within a sky region of 28  deg^{2} (90% probability) and had a luminosity distance of 40_{-14}^{+8}  Mpc, the closest and most precisely localized gravitational-wave signal yet. The association with the γ-ray burst GRB 170817A, detected by Fermi-GBM 1.7 s after the coalescence, corroborates the hypothesis of a neutron star merger and provides the first direct evidence of a link between these mergers and short γ-ray bursts. Subsequent identification of transient counterparts across the electromagnetic spectrum in the same location further supports the interpretation of this event as a neutron star merger. This unprecedented joint gravitational and electromagnetic observation provides insight into astrophysics, dense matter, gravitation, and cosmology.

GW170814: A Three-Detector Observation of Gravitational Waves from a Binary Black Hole Coalescence

On August 14, 2017 at 10∶30:43 UTC, the Advanced Virgo detector and the two Advanced LIGO detectors coherently observed a transient gravitational-wave signal produced by the coalescence of two stellar mass black holes, with a false-alarm rate of ≲1 in 27 000 years. The signal was observed with a three-detector network matched-filter signal-to-noise ratio of 18. The inferred masses of the initial black holes are 30.5_{-3.0}^{+5.7}M_{⊙} and 25.3_{-4.2}^{+2.8}M_{⊙} (at the 90% credible level). The luminosity distance of the source is 540_{-210}^{+130}  Mpc, corresponding to a redshift of z=0.11_{-0.04}^{+0.03}. A network of three detectors improves the sky localization of the source, reducing the area of the 90% credible region from 1160   deg^{2} using only the two LIGO detectors to 60  deg^{2} using all three detectors. For the first time, we can test the nature of gravitational-wave polarizations from the antenna response of the LIGO-Virgo network, thus enabling a new class of phenomenological tests of gravity.

GW170104: Observation of a 50-Solar-Mass Binary Black Hole Coalescence at Redshift 0.2

We describe the observation of GW170104, a gravitational-wave signal produced by the coalescence of a pair of stellar-mass black holes. The signal was measured on January 4, 2017 at 10∶11:58.6 UTC by the twin advanced detectors of the Laser Interferometer Gravitational-Wave Observatory during their second observing run, with a network signal-to-noise ratio of 13 and a false alarm rate less than 1 in 70 000 years. The inferred component black hole masses are 31.2_{-6.0}^{+8.4}M_{⊙} and 19.4_{-5.9}^{+5.3}M_{⊙} (at the 90% credible level). The black hole spins are best constrained through measurement of the effective inspiral spin parameter, a mass-weighted combination of the spin components perpendicular to the orbital plane, χ_{eff}=-0.12_{-0.30}^{+0.21}. This result implies that spin configurations with both component spins positively aligned with the orbital angular momentum are disfavored. The source luminosity distance is 880_{-390}^{+450}  Mpc corresponding to a redshift of z=0.18_{-0.07}^{+0.08}. We constrain the magnitude of modifications to the gravitational-wave dispersion relation and perform null tests of general relativity. Assuming that gravitons are dispersed in vacuum like massive particles, we bound the graviton mass to m_{g}≤7.7×10^{-23}  eV/c^{2}. In all cases, we find that GW170104 is consistent with general relativity.

Upper Limits on the Stochastic Gravitational-Wave Background from Advanced LIGO's First Observing Run

A wide variety of astrophysical and cosmological sources are expected to contribute to a stochastic gravitational-wave background. Following the observations of GW150914 and GW151226, the rate and mass of coalescing binary black holes appear to be greater than many previous expectations. As a result, the stochastic background from unresolved compact binary coalescences is expected to be particularly loud. We perform a search for the isotropic stochastic gravitational-wave background using data from Advanced Laser Interferometer Gravitational Wave Observatory's (aLIGO) first observing run. The data display no evidence of a stochastic gravitational-wave signal. We constrain the dimensionless energy density of gravitational waves to be Ω_{0}<1.7×10^{-7} with 95% confidence, assuming a flat energy density spectrum in the most sensitive part of the LIGO band (20-86 Hz). This is a factor of ∼33 times more sensitive than previous measurements. We also constrain arbitrary power-law spectra. Finally, we investigate the implications of this search for the background of binary black holes using an astrophysical model for the background.

Directional Limits on Persistent Gravitational Waves from Advanced LIGO's First Observing Run

We employ gravitational-wave radiometry to map the stochastic gravitational wave background expected from a variety of contributing mechanisms and test the assumption of isotropy using data from the Advanced Laser Interferometer Gravitational Wave Observatory's (aLIGO) first observing run. We also search for persistent gravitational waves from point sources with only minimal assumptions over the 20-1726 Hz frequency band. Finding no evidence of gravitational waves from either point sources or a stochastic background, we set limits at 90% confidence. For broadband point sources, we report upper limits on the gravitational wave energy flux per unit frequency in the range F_{α,Θ}(f)<(0.1-56)×10^{-8}    erg cm^{-2} s^{-1} Hz^{-1}(f/25  Hz)^{α-1} depending on the sky location Θ and the spectral power index α. For extended sources, we report upper limits on the fractional gravitational wave energy density required to close the Universe of Ω(f,Θ)<(0.39-7.6)×10^{-8}  sr^{-1}(f/25  Hz)^{α} depending on Θ and α. Directed searches for narrowband gravitational waves from astrophysically interesting objects (Scorpius X-1, Supernova 1987 A, and the Galactic Center) yield median frequency-dependent limits on strain amplitude of h_{0}<(6.7,5.5,  and  7.0)×10^{-25}, respectively, at the most sensitive detector frequencies between 130-175 Hz. This represents a mean improvement of a factor of 2 across the band compared to previous searches of this kind for these sky locations, considering the different quantities of strain constrained in each case.

Characterization of transient noise in Advanced LIGO relevant to gravitational wave signal GW150914

On September 14, 2015, a gravitational wave signal from a coalescing black hole binary system was observed by the Advanced LIGO detectors. This paper describes the transient noise backgrounds used to determine the significance of the event (designated GW150914) and presents the results of investigations into potential correlated or uncorrelated sources of transient noise in the detectors around the time of the event. The detectors were operating nominally at the time of GW150914. We have ruled out environmental influences and non-Gaussian instrument noise at either LIGO detector as the cause of the observed gravitational wave signal.

GW151226: Observation of Gravitational Waves from a 22-Solar-Mass Binary Black Hole Coalescence

We report the observation of a gravitational-wave signal produced by the coalescence of two stellar-mass black holes. The signal, GW151226, was observed by the twin detectors of the Laser Interferometer Gravitational-Wave Observatory (LIGO) on December 26, 2015 at 03:38:53 UTC. The signal was initially identified within 70 s by an online matched-filter search targeting binary coalescences. Subsequent off-line analyses recovered GW151226 with a network signal-to-noise ratio of 13 and a significance greater than 5σ. The signal persisted in the LIGO frequency band for approximately 1 s, increasing in frequency and amplitude over about 55 cycles from 35 to 450 Hz, and reached a peak gravitational strain of 3.4_{-0.9}^{+0.7}×10^{-22}. The inferred source-frame initial black hole masses are 14.2_{-3.7}^{+8.3}M_{⊙} and 7.5_{-2.3}^{+2.3}M_{⊙}, and the final black hole mass is 20.8_{-1.7}^{+6.1}M_{⊙}. We find that at least one of the component black holes has spin greater than 0.2. This source is located at a luminosity distance of 440_{-190}^{+180}  Mpc corresponding to a redshift of 0.09_{-0.04}^{+0.03}. All uncertainties define a 90% credible interval. This second gravitational-wave observation provides improved constraints on stellar populations and on deviations from general relativity.

Properties of the Binary Black Hole Merger GW150914

On September 14, 2015, the Laser Interferometer Gravitational-Wave Observatory (LIGO) detected a gravitational-wave transient (GW150914); we characterize the properties of the source and its parameters. The data around the time of the event were analyzed coherently across the LIGO network using a suite of accurate waveform models that describe gravitational waves from a compact binary system in general relativity. GW150914 was produced by a nearly equal mass binary black hole of masses 36_{-4}^{+5}M_{⊙} and 29_{-4}^{+4}M_{⊙}; for each parameter we report the median value and the range of the 90% credible interval. The dimensionless spin magnitude of the more massive black hole is bound to be <0.7 (at 90% probability). The luminosity distance to the source is 410_{-180}^{+160}  Mpc, corresponding to a redshift 0.09_{-0.04}^{+0.03} assuming standard cosmology. The source location is constrained to an annulus section of 610  deg^{2}, primarily in the southern hemisphere. The binary merges into a black hole of mass 62_{-4}^{+4}M_{⊙} and spin 0.67_{-0.07}^{+0.05}. This black hole is significantly more massive than any other inferred from electromagnetic observations in the stellar-mass regime.

GW150914: First results from the search for binary black hole coalescence with Advanced LIGO

On September 14, 2015 at 09:50:45 UTC the two detectors of the Laser Interferometer Gravitational-wave Observatory (LIGO) simultaneously observed the binary black hole merger GW150914. We report the results of a matched-filter search using relativistic models of compact-object binaries that recovered GW150914 as the most significant event during the coincident observations between the two LIGO detectors from September 12 to October 20, 2015. GW150914 was observed with a matched filter signal-to-noise ratio of 24 and a false alarm rate estimated to be less than 1 event per 203000 years, equivalent to a significance greater than 5.1 σ.

GW150914: First results from the search for binary black hole coalescence with Advanced LIGO

On September 14, 2015 at 09:50:45 UTC the two detectors of the Laser Interferometer Gravitational-wave Observatory (LIGO) simultaneously observed the binary black hole merger GW150914. We report the results of a matched-filter search using relativistic models of compact-object binaries that recovered GW150914 as the most significant event during the coincident observations between the two LIGO detectors from September 12 to October 20, 2015. GW150914 was observed with a matched filter signal-to-noise ratio of 24 and a false alarm rate estimated to be less than 1 event per 203000 years, equivalent to a significance greater than 5.1 σ.

Tests of General Relativity with GW150914

The LIGO detection of GW150914 provides an unprecedented opportunity to study the two-body motion of a compact-object binary in the large-velocity, highly nonlinear regime, and to witness the final merger of the binary and the excitation of uniquely relativistic modes of the gravitational field. We carry out several investigations to determine whether GW150914 is consistent with a binary black-hole merger in general relativity. We find that the final remnant's mass and spin, as determined from the low-frequency (inspiral) and high-frequency (postinspiral) phases of the signal, are mutually consistent with the binary black-hole solution in general relativity. Furthermore, the data following the peak of GW150914 are consistent with the least-damped quasinormal mode inferred from the mass and spin of the remnant black hole. By using waveform models that allow for parametrized general-relativity violations during the inspiral and merger phases, we perform quantitative tests on the gravitational-wave phase in the dynamical regime and we determine the first empirical bounds on several high-order post-Newtonian coefficients. We constrain the graviton Compton wavelength, assuming that gravitons are dispersed in vacuum in the same way as particles with mass, obtaining a 90%-confidence lower bound of 10^{13}  km. In conclusion, within our statistical uncertainties, we find no evidence for violations of general relativity in the genuinely strong-field regime of gravity.

GW150914: Implications for the Stochastic Gravitational-Wave Background from Binary Black Holes

The LIGO detection of the gravitational wave transient GW150914, from the inspiral and merger of two black holes with masses ≳30M_{⊙}, suggests a population of binary black holes with relatively high mass. This observation implies that the stochastic gravitational-wave background from binary black holes, created from the incoherent superposition of all the merging binaries in the Universe, could be higher than previously expected. Using the properties of GW150914, we estimate the energy density of such a background from binary black holes. In the most sensitive part of the Advanced LIGO and Advanced Virgo band for stochastic backgrounds (near 25 Hz), we predict Ω_{GW}(f=25  Hz)=1.1_{-0.9}^{+2.7}×10^{-9} with 90% confidence. This prediction is robustly demonstrated for a variety of formation scenarios with different parameters. The differences between models are small compared to the statistical uncertainty arising from the currently poorly constrained local coalescence rate. We conclude that this background is potentially measurable by the Advanced LIGO and Advanced Virgo detectors operating at their projected final sensitivity.

GW150914: The Advanced LIGO Detectors in the Era of First Discoveries

Following a major upgrade, the two advanced detectors of the Laser Interferometer Gravitational-wave Observatory (LIGO) held their first observation run between September 2015 and January 2016. With a strain sensitivity of 10^{-23}/sqrt[Hz] at 100 Hz, the product of observable volume and measurement time exceeded that of all previous runs within the first 16 days of coincident observation. On September 14, 2015, the Advanced LIGO detectors observed a transient gravitational-wave signal determined to be the coalescence of two black holes [B. P. Abbott et al., Phys. Rev. Lett. 116, 061102 (2016)], launching the era of gravitational-wave astronomy. The event, GW150914, was observed with a combined signal-to-noise ratio of 24 in coincidence by the two detectors. Here, we present the main features of the detectors that enabled this observation. At full sensitivity, the Advanced LIGO detectors are designed to deliver another factor of 3 improvement in the signal-to-noise ratio for binary black hole systems similar in mass to GW150914.

Observation of Gravitational Waves from a Binary Black Hole Merger

On September 14, 2015 at 09:50:45 UTC the two detectors of the Laser Interferometer Gravitational-Wave Observatory simultaneously observed a transient gravitational-wave signal. The signal sweeps upwards in frequency from 35 to 250 Hz with a peak gravitational-wave strain of 1.0×10(-21). It matches the waveform predicted by general relativity for the inspiral and merger of a pair of black holes and the ringdown of the resulting single black hole. The signal was observed with a matched-filter signal-to-noise ratio of 24 and a false alarm rate estimated to be less than 1 event per 203,000 years, equivalent to a significance greater than 5.1σ. The source lies at a luminosity distance of 410(-180)(+160)  Mpc corresponding to a redshift z=0.09(-0.04)(+0.03). In the source frame, the initial black hole masses are 36(-4)(+5)M⊙ and 29(-4)(+4)M⊙, and the final black hole mass is 62(-4)(+4)M⊙, with 3.0(-0.5)(+0.5)M⊙c(2) radiated in gravitational waves. All uncertainties define 90% credible intervals. These observations demonstrate the existence of binary stellar-mass black hole systems. This is the first direct detection of gravitational waves and the first observation of a binary black hole merger.

Virulence profile and genetic structure of a North Dakota population of Pyrenophora teres f. teres, the causal agent of net form net blotch of barley

A Pyrenophora teres f. teres population in North Dakota was analyzed for virulence variation and genetic diversity using 75 monospore isolates that were collected across a 4-year period (2004 to 2007) from two North Dakota State University agricultural experiment stations at Fargo and Langdon. Pathogenicity tests by inoculation onto 22 barley differential lines at seedling stage revealed 49 pathotypes, indicating a wide range of pathogenic diversity. Two-way analysis of variance of disease ratings revealed a significant difference in the virulence among isolates and in the resistance among barley lines, as well as in the interactions between the two. 'CI5791', 'Algerian', and 'Heartland' were three barley lines showing a high level of seedling resistance to all North Dakota isolates tested; however, many previously reported resistance genes have been overcome. Forty multilocus genotypes were identified from this set of isolates by genotyping at 13 simple-sequence repeat loci. High percentages of clonal cultures were detected in the samplings from 2005 and 2007 in Fargo and 2005 in Langdon. Using a clone-corrected sample set, the mean gene diversity (h) was estimated to be 0.58, approximately the same for both locations. The calculated Wright's F(ST) value is small (0.11) but was significantly >0, indicating a significant differentiation between the Fargo and Langdon populations. In the gametic disequilibrium test, only 3 of 78 possible pairwise comparisons over all isolates showed significant (P < 0.05) nonrandom association, suggesting a random mating mode. Our results suggest that the populations from the two locations are derived from a common source and undergo frequent recombination. This research provides important information for barley breeders regarding development and deployment of cultivars with resistance to net form net blotch in this region.

Maize as a New Host for Oat blue dwarf virus

Oat blue dwarf virus (OBDV) is a marafivirus present throughout the North American Great Plains and is found at low incidence levels in barley, oats, and flax in the Upper Midwest United States. Cropping patterns in this region have changed considerably in recent years, with much greater acreages devoted to maize in areas historically planted to small grains. Considering that OBDV is endemic in small grains in this region and that its aster leafhopper vector (Macrosteles quadrilineatus) is commonly detected in maize (2), we questioned whether maize might be a host for OBDV. Although Westdal (4) reported that maize was not a host for OBDV, it is the primary host for the related Maize rayado fino virus (MRFV) transmitted by Dalbulus maidis. MRFV is the type member of the marafiviruses and ranges from South America to the southern United States. To reevaluate the ability of maize to serve as a host for OBDV, viruliferous aster leafhoppers were allowed to feed on young maize seedlings for a 7-day inoculation access period. Plants were assayed for the presence of OBDV by ELISA 21 days after leafhopper removal. Initially, open-pollinated Sunglow sweet corn was tested in three experiments, with infection rates of 17 to 100%. A test of hybrid Sunglow resulted in 63% infection. These are comparable to transmission levels obtained when oat and barley plants are fed upon by viruliferous leafhoppers. Subsequently, 10 additional varieties of sweet and field corn were tested to determine if they could serve as hosts for OBDV. Sweet corn included Silver Queen, Peaches and Cream, Morning Star, Sugar Dots, Kandy Korn, and Golden Cross Bantam. Field corn included four lines provided by the maize breeding program of M. Carena at North Dakota State University (056640, 056643, 056612, and 056652). At least one plant was infected in all sweet and field corn varieties except 056612. Infected plants were largely asymptomatic, although a very faint stipple-striping was observed on some plants. To determine whether leafhoppers could acquire OBDV from infected maize and transmit the virus to other hosts, healthy leafhoppers were fed upon detached leaves of infected maize for 4 days (approximately 30 days after initial infection) and subsequently transferred three times at weekly intervals to barley and oats. Infection rates of 42 to 55% were observed in target plants, indicating efficient transmission from maize to other cereal hosts. The extent of natural infection of maize by OBDV or economic loss, if any, remains to be determined. This discovery extends the host range of OBDV to include maize and suggests that maize has the potential to serve as a natural reservoir for OBDV. The identification of hosts for known and new marafiviruses, such as those recently detected in citrus (3) and grape (1), will expand our understanding of the ecology and epidemiology of viruses within this group. References: (1) M. Al Rwahnih. Virology 387:395, 2009. (2) J. L. Capinera. Page 320 in: Encyclopedia of Entomology. 2nd ed. Springer Publishing, New York, NY, 2008. (3) W. Maccheroni et al. J. Virol. 79:3028, 2005. (4) P. Westdal. Can. J. Bot. 46:1431, 1968.

WITHDRAWN: Use of Interval Schedules to Examine Motivation and Sustained Attention

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A region of barley chromosome 6H harbors multiple major genes associated with net type net blotch resistance

Net type net blotch (NTNB), caused by Pyrenophora teres f. teres Drechs., is prevalent in barley growing regions worldwide. A population of 118 doubled haploid (DH) lines developed from a cross between barley cultivars 'Rika' and 'Kombar' were used to evaluate resistance to NTNB due to their differential reaction to various isolates of P. teres f. teres. Rika was resistant to P. teres f. teres isolate 15A and susceptible to isolate 6A. Conversely, Kombar was resistant to 6A, but susceptible to 15A. A progeny isolate of a 15A x 6A cross identified as 15A x 6A#4 was virulent on both parental lines. The Rika/Kombar (RK) DH population was evaluated for disease reactions to the three isolates. Isolate 15A induced a resistant:susceptible ratio of 78:40 (R:S) whereas isolate 6A induced a resistant:susceptible ratio of 40:78. All but two lines had opposite disease reactions indicating two major resistance genes linked in repulsion. Progeny isolate 15A x 6A#4 showed a resistant:susceptible ratio of 1:117 with the one resistant line also being the single line that was resistant to both 15A and 6A. An RK F(2) population segregated in a 1:3 (R:S) ratio for both 15A and 6A indicating that resistance is recessive. Molecular markers were used to identify a region on chromosome 6H that harbors the two NTNB resistance genes. This work shows that multiple NTNB resistance genes exist at the locus on chromosome 6H, and the recombinant DH line harboring the resistance alleles from both parents will be useful for the development of NTNB-resistant barley germplasm.

Externalizing symptoms among children of alcoholic parents: Entry points for an antisocial pathway to alcoholism

The authors examined heterogeneity in risk for externalizing symptoms in children of alcoholic parents, as it may inform the search for entry points into an antisocial pathway to alcoholism. That is, they tested whether the number of alcoholic parents in a family, the comorbid subtype of parental alcoholism, and the gender of the child predicted trajectories of externalizing symptoms over the early life course, as assessed in high-risk samples of children of alcoholic parents and matched controls. Through integrative analyses of 2 independent, longitudinal studies, they showed that children with either an antisocial alcoholic parent or 2 alcoholic parents were at greatest risk for externalizing symptoms. Moreover, children with a depressed alcoholic parent did not differ from those with an antisocial alcoholic parent in reported symptoms. These findings were generally consistent across mother, father, and adolescent reports of symptoms; child gender and child age (ages 2 through 17); and the 2 independent studies examined. Multialcoholic and comorbid-alcoholic families may thus convey a genetic susceptibility to dysregulation along with environments that both exacerbate this susceptibility and provide few supports to offset it.

First Report of Beet black scorch virus in the United States

In October of 2005, sugar beet (Beta vulgaris L.) plants exhibiting symptoms of rhizomania caused by Beet necrotic yellow vein virus (BNYVV) (3) were observed in a production field near Greeley, CO. The roots of seven plants exhibiting moderate to severe symptoms characteristic of this disease were tested using double-antibody sandwich enzyme-linked immunosorbent assay with anti-BNYVV antiserum from rabbits. Of these, only two roots exhibiting the mildest symptoms tested positive for BNYVV (all roots tested negative for the presence of the related Beet soilborne mosaic virus (BSBMV). 'Hairy' lateral roots characteristic of the disease were combined from the remaining five roots, ground in phosphate buffer, and the supernatant from the suspension was mechanically applied to leaves of Chenopodium quinoa in an effort to isolate an infectious agent. Five days postinoculation (dpi), yellow lesions with necrotic centers were visible on inoculated leaves, well in advance of those typically observed for BNYVV or BSBMV. Lesions exhibiting a similar rate of development on C. quinoa subsequently were induced from extracts of root vascular tissue prepared from four of seven additional beet roots tested from this location. Transfer of the infection from the C. quinoa lesions to 32 healthy C. quinoa and 10 sugar beet plants (hybrid ACH9369; American Crystal Sugar Co., Moorhead MN) resulted in 100% infection. Inoculated leaves of C. quinoa exhibited a high density of necrotic local lesions within 3 dpi, whereas inoculated leaves of sugar beet exhibited pinpoint, necrotic to diffuse, chlorotic local lesions evident by 5 dpi. Electron microscopic examination of fixed, ultra-thin sections of symptomatic C. quinoa leaf tissue revealed aggregates of virus-like particles of icosahedral symmetry within the cell cytoplasm. Following a virus minipreparation procedure, nucleic acid extracted from the partially purified virus was found to be single-stranded RNA by ribonuclease digestion and alone was infectious when inoculated to C. quinoa leaves. The apparently monopartite RNA genome was 3.5 kb long and a candidate for the single coat protein (CP) had a mass of ˜25 kDa. The sole reference set found in the literature for a virus naturally occurring on sugar beet with similar characteristics was that for Beet black scorch virus (BBSV), a virus recently accepted by the ICTV into the genus Necrovirus within the family Tombusviridae (2). Prior to this communication, BBSV has only been reported in China where it was first documented affecting sugar beet in the late 1980s (1). Using the published sequence of BBSV (Genbank Accession No. AY626780), DNA primers directed to the 3' half of the BBSV genome were used in reverse transcription-polymerase chain reaction to produce an amplicon from the unknown virus. Sequencing the amplicon revealed 88.8% nucleotide sequence identity to the BBSV CP gene and 97% amino acid sequence identity to the predicted CP gene product. Combined, the nucleotide sequence and physical characteristics confirm the presence of BBSV in a U.S. sugarbeet field for the first time. To our knowledge, this is the first report of the occurrence of BBSV outside of China. References: (1) Y. Cao et al. Arch. Virol. 147:2431, 2002. (2) C. M. Fauquet et al. Eighth Report of the International Committee on the Taxonomy of Viruses. Academic Press, New York, 2005. (3) C. M. Rush. Ann. Rev. Phytopathol. 41:567, 2003.

MCM2-7 complexes bind chromatin in a distributed pattern surrounding the origin recognition complex in Xenopus egg extracts

The MCM2-7 complex is believed to function as the eukaryotic replicative DNA helicase. It is recruited to chromatin by the origin recognition complex (ORC), Cdc6, and Cdt1, and it is activated at the G(1)/S transition by Cdc45 and the protein kinases Cdc7 and Cdk2. Paradoxically, the number of chromatin-bound MCM complexes greatly exceeds the number of bound ORC complexes. To understand how the high MCM2-7:ORC ratio comes about, we examined the binding of these proteins to immobilized linear DNA fragments in Xenopus egg extracts. The minimum length of DNA required to recruit ORC and MCM2-7 was approximately 80 bp, and the MCM2-7:ORC ratio on this fragment was approximately 1:1. With longer DNA fragments, the MCM2-7:ORC ratio increased dramatically, indicating that MCM complexes normally become distributed over a large region of DNA surrounding ORC. Only a small subset of the chromatin-bound MCM2-7 complexes recruited Cdc45 at the onset of DNA replication, and unlike Cdc45, MCM2-7 was not limiting for DNA replication. However, all the chromatin-bound MCM complexes may be functional, because they were phosphorylated in a Cdc7-dependent fashion, and because they could be induced to support Cdk2-dependent Cdc45 loading. The data suggest that in Xenopus egg extracts, origins of replication contain multiple, distributed, initiation-competent MCM2-7 complexes.

The family Tymoviridae

The family Tymoviridae comprises the genus Tymovirus, from which it derives its name, the genus Marafivirus and the newly established genus Maculavirus. Members of the family share the following characteristics: (i) non-enveloped isometric particles c. 30 um in diameter, with a rounded contour and prominent surface structures, and clustering of coat protein subunits in pentamers and hexamers; (ii) the presence in preparations of purified virus particles of two centrifugal components, made up of non-infectious protein shells (T) that may contain small amounts of RNA (primarily subgenomic coat protein mRNA) and of infectious nucleoproteins (B), that contain the virus genome; (iii) possession of a positive-sense, single-stranded RNA genome with an unusually high cytidine content (32 to c. 50%), capped at the 5' terminus and containing a very large ORF encodes replication-related proteins analogous to those of other taxa of the "alpha-like" supergroup of ssRNA viruses; (iv) a replication strategy possibly encompassing posttranslational proteolytic cleavage of the polypeptide encoded by ORF1 by a papain-like virus-encoded protease, and coat protein expression via a subgenomic RNA; (v) the presence in infected cells of cytopathic structures, thought to be the sites of RNA replication, originating from severely altered chloroplasts and/or mitochondria, the periphery of which is lined with vesicles produced by the localized invaginations of the bounding membrane. There are 23, 4, and 2 known species in the genera Tymovirus, Marafivirus and Maculavirus, respectively. The genus Marafivirus also contains one tentative species.

Mutations in TGIF cause holoprosencephaly and link NODAL signalling to human neural axis determination

Holoprosencephaly (HPE) is the most common structural defect of the developing forebrain in humans (1 in 250 conceptuses, 1 in 16,000 live-born infants). HPE is aetiologically heterogeneous, with both environmental and genetic causes. So far, three human HPE genes are known: SHH at chromosome region 7q36 (ref. 6); ZIC2 at 13q32 (ref. 7); and SIX3 at 2p21 (ref. 8). In animal models, genes in the Nodal signalling pathway, such as those mutated in the zebrafish mutants cyclops (refs 9,10), squint (ref. 11) and one-eyed pinhead (oep; ref. 12), cause HPE. Mice heterozygous for null alleles of both Nodal and Smad2 have cyclopia. Here we describe the involvement of the TG-interacting factor (TGIF), a homeodomain protein, in human HPE. We mapped TGIF to the HPE minimal critical region in 18p11.3. Heterozygous mutations in individuals with HPE affect the transcriptional repression domain of TGIF, the DNA-binding domain or the domain that interacts with SMAD2. (The latter is an effector in the signalling pathway of the neural axis developmental factor NODAL, a member of the transforming growth factor-beta (TGF-beta) family.) Several of these mutations cause a loss of TGIF function. Thus, TGIF links the NODAL signalling pathway to the bifurcation of the human forebrain and the establishment of ventral midline structures.

Isolated sulfite oxidase deficiency: review of two cases in one family

OBJECTIVE

The authors describe two cases of isolated sulfite oxidase deficiency found in one family. This is a rare autosomal-recessive disorder presenting at birth with seizures, severe neurologic disease, and ectopia lentis. It can be easily missed with metabolic screening; however, the finding of lens subluxation stresses the importance of ophthalmic assessment in making the diagnosis.

DESIGN

Two observational case reports.

INTERVENTION/METHODS

Ophthalmic assessment, biochemical assay for specific urinary and plasma metabolites, magnetic resonance imaging, and gene sequencing were used to make the diagnosis of the disease in the proband. The diagnosis was subsequently recognized in a previously affected sibling after the postmortem neuropathology was reviewed. Mutation analysis was performed on cultured fibroblasts from the proband to identify and categorize the specific mutation responsible for the disease in the family. From this, future prenatal detection of sulfite oxidase deficiency is possible.

MAIN OUTCOME MEASURES

The diagnosis of sulfite oxidase deficiency was established in this family, enabling appropriate genetic counseling and recurrence risk estimation.

RESULTS

Point mutations were found in both alleles of the sulfite oxidase gene in the proband. The first is a 623C-->A mutation, which predicts an A208D substitution, and the second is a 1109C-->A, which predicts an S370Y substitution. Both residues A208D and S370Y are critical for sulfite oxidase activity.

CONCLUSIONS

Isolated sulfite oxidase deficiency is a rare heritable disease for which mutation analysis can allow accurate prenatal screening. It often is difficult to diagnose by clinical presentation alone, but the critical finding of lens subluxation accompanying seizures and diffuse neurologic disease in an infant should alert the physician to the diagnosis.

Human cyclin K, a novel RNA polymerase II-associated cyclin possessing both carboxy-terminal domain kinase and Cdk-activating kinase activity

The gene coding for human cyclin K was isolated as a CPR (cell-cycle progression restoration) gene by virtue of its ability to impart a Far- phenotype to the budding yeast Saccharomyces cerevisiae and to rescue the lethality of a deletion of the G1 cyclin genes CLN1, CLN2, and CLN3. The cyclin K gene encodes a 357-amino-acid protein most closely related to human cyclins C and H, which have been proposed to play a role in regulating basal transcription through their association with and activation of cyclin-dependent kinases (Cdks) that phosphorylate the carboxyl-terminal domain (CTD) of the large subunit of RNA polymerase II (RNAP II). Murine and Drosophila melanogaster homologs of cyclin K have also been identified. Cyclin K mRNA is ubiquitously expressed in adult mouse and human tissues, but is most abundant in the developing germ cells of the adult testis and ovaries. Cyclin K is associated with potent CTD kinase and Cdk kinase (CAK) activity in vitro and coimmunoprecipitates with the large subunit of RNAP II. Thus, cyclin K represents a new member of the "transcription" cyclin family which may play a dual role in regulating Cdk and RNAP II activity.

Human CPR (cell cycle progression restoration) genes impart a Far- phenotype on yeast cells

Regulated cell cycle progression depends on the proper integration of growth control pathways with the basic cell cycle machinery. While many of the central molecules such as cyclins, CDKs, and CKIs are known, and many of the kinases and phosphatases that modify the CDKs have been identified, little is known about the additional layers of regulation that impinge upon these molecules. To identify new regulators of cell proliferation, we have selected for human and yeast cDNAs that when overexpressed were capable of specifically overcoming G1 arrest signals from the cell cycle branch of the mating pheromone pathway, while still maintaining the integrity of the transcriptional induction branch. We have identified 13 human CPR (cell cycle progression restoration) genes and 11 yeast OPY (overproduction-induced pheromone-resistant yeast) genes that specifically block the G1 arrest by mating pheromone. The CPR genes represent a variety of biochemical functions including a new cyclin, a tumor suppressor binding protein, chaperones, transcription factors, translation factors, RNA-binding proteins, as well as novel proteins. Several CPR genes require individual CLNs to promote pheromone resistance and those that require CLN3 increase the basal levels of Cln3 protein. Moreover, several of the yeast OPY genes have overlapping functions with the human CPR genes, indicating a possible conservation of roles.

Oat blue dwarf marafivirus resembles the tymoviruses in sequence, genome organization, and expression strategy

The complete nucleotide sequence and genome organization of oat blue dwarf marafivirus (OBDV) were determined. The 6509 nucleotide RNA genome encodes a putative 227-kDa polyprotein (p227) with sequence motifs similar to the methyltransferase, papain-like protease, helicase, and polymerase motifs present in the nonstructural proteins of other positive strand RNA viruses. The 3' end of the open reading frame (ORF) that encodes p227 (ORF 227) also encodes the two capsid proteins: a 24-kDa capsid protein is presumably cleaved from the p227 polyprotein, whereas the 21-kDa capsid protein appears to be translated from a subgenomic RNA (sgRNA). Encoded amino acid and nucleotide sequence comparisons, as well as the OBDV genome expression strategy, show that OBDV closely resembles the tymoviruses. OBDV differs from the tymoviruses in its general biology, in its lack of a putative movement gene that overlaps the replication-associated genes, and in its fusion of the capsid gene sequences to the major ORF. OBDV also possesses a 3' poly(A) tail, as compared to the tRNA-like structures found in most tymoviral genomes. Due to the strong similarities in genome sequence and expression strategy, OBDV, and presumably the other marafiviruses, should be considered a member of the tymovirus lineage of the alpha-like plant viruses.

Imprinting of the gene encoding a human cyclin-dependent kinase inhibitor, p57KIP2, on chromosome 11p15

Parental origin-specific alterations of chromosome 11p15 in human cancer suggest the involvement of one or more maternally expressed imprinted genes involved in embryonal tumor suppression and the cancer-predisposing Beckwith-Wiedemann syndrome (BWS). The gene encoding cyclin-dependent kinase inhibitor p57KIP2, whose overexpression causes G1 phase arrest, was recently cloned and mapped to this band. We find that the p57KIP2 gene is imprinted, with preferential expression of the maternal allele. However, the imprint is not absolute, as the paternal allele is also expressed at low levels in most tissues, and at levels comparable to the maternal allele in fetal brain and some embryonal tumors. The biochemical function, chromosomal location, and imprinting of the p57KIP2 gene match the properties predicted for a tumor suppressor gene at 11p15.5. However, as the p57KIP2 gene is 500 kb centromeric to the gene encoding insulin-like growth factor 2, it is likely to be part of a large domain containing other imprinted genes. Thus, loss of heterozygosity or loss of imprinting might simultaneously affect several genes at this locus that together contribute to tumor and/or growth- suppressing functions that are disrupted in BWS and embryonal tumors.

A single nucleotide substitution in the alpha a gene confers oat pathogenicity to barley stripe mosaic virus strain ND18

A 236-nucleotide region from the alpha a gene of strain CV42 (pathogenic to oat), when substituted for the homologous region in strain ND18 (nonpathogenic to oat), was shown previously to confer a near wild-type oat pathogenicity to this strain (Weiland and Edwards, 1994, Virology 201: 116-126). The data suggested that six amino acid substitutions in the alpha a gene were responsible for the differences in oat pathogenicity, and that threonine-724, encoded by CV42, might be a critical amino acid in determining pathogenicity of barley stripe mosaic virus (BSMV) to oat. In the present work, codons specifying T-724, I-764, and N-785 (encoded by CV42 RNA alpha) were substituted individually and in combination for those coding for P-724, T-764, and K-785 (encoded by ND18 RNA alpha), respectively, by site-directed mutagenesis. The core K-733, T-734, and K-736 positions (CV42) were substituted for Q-733, S-734, and Q-736 (ND18) as a single block. The results of inoculations with these mutants indicate that the C2261-->A2261 nucleotide substitution (P-724-->T-724) by itself is sufficient to enable strain ND18 to infect oat plants, although poorly. Additional substitution of CV42 codons into ND18 RNA alpha at the remaining five positions altered symptom type, decreased the timing of the appearance of symptoms, and increased the percentage of plants infected per inoculation. Nonetheless, all mutants accumulated to similar levels in inoculated oat protoplasts after a 24-h period. Using a recombinant RNA beta from which beta-glucuronidase could be expressed, results were obtained suggesting that the multiplication of strain ND18 and the nonpathogenic variants generated in the study was restricted in the inoculated leaf. The data indicate a potential pathway by which pathogenicity to oat evolved in BSMV.