Search

Mate guarding is one of the most common tactics in sperm competition. Males are expected to guard their mates when costs of guarding (accrued from physical confrontations with rivals and/or reduced foraging) are low relative to the benefits of ensuring mating opportunities and paternity. We investigated mate guarding in the jumping spider Phidippus clarus, a species where males defend immature subadult females against rival males and attempt to mate with the females soon after they mature. We assessed a possible social cost of mate-guarding behaviour (male intersexual signalling) using laser vibrometry and respirometry. We found that males produced a unique set of signals when guarding subadult females and that these signals were energetically costly (guarding courtship). Mating success did not differ between males that successfully defended a subadult female and males that located an unmated, mature virgin female. This suggests that guarding courtship does not directly influence mate choice and that males may use different tactics depending on female availability to ensure fitness. To explore further the effect of mate guarding and guarding courtship, we experimentally sealed male's copulatory organs (males could guard normally but were unable to transfer sperm) and compared mating rates of sealed versus intact males. We found that guarding behaviour, and not sperm transfer, significantly influenced female remating behaviour. Placed in the context of P.clarus life history, our results highlight the ongoing sexual conflict between males and females and the hidden costs and benefits of mate-guarding behaviour.

Abstract We propose a program at B-factories of inclusive, multi-track displaced vertex searches, which are expected to be low background and give excellent sensitivity to non-minimal hidden sectors. Multi-particle hidden sectors often include long-lived particles (LLPs) which result from approximate symmetries, and we classify the possible decays of GeV-scale LLPs in an effective field theory framework. Considering several LLP production modes, including dark photons and dark Higgs bosons, we study the sensitivity of LLP searches with different number of displaced vertices per event and track requirements per displaced vertex, showing that inclusive searches can have sensitivity to a large range of hidden sector models that are otherwise unconstrained by current or planned searches.

Forty patients were randomly assigned to receive either the individualized learning activity packages or classroom instruction. Effectiveness was evaluated on the basis of fasting plasma glucose, glycosylated hemoglobin, percent of ideal body weight, and knowledge and behavior scores. No significant differences were found between the groups at entry or at the 2-month follow-up. At the 5-month follow-up, the group that received the learning activity packages scored significantly higher on knowledge assessment, significantly increased their behavior score, and decreased their percent of ideal body weight. Patients who received classroom instruction increased their behavior score and exhibited significantly decreased glycosylated hemoglobin levels. Behavior and blood glucose levels were significantly correlated. Although the learning activity packages proved effective in increasing knowledge, no significant improvement was observed in blood glucose levels. [ABSTRACT FROM AUTHOR]

Gle1 regulates gene expression at multiple steps from transcription to mRNA export to translation under stressed and non-stressed conditions. To better understand Gle1 function in stressed human cells, specific antibodies were generated that recognized the phosphorylation of threonine residue 102 (T102) in Gle1. A series of in vitro kinase assays indicated that T102 phosphorylation serves as a priming event for further phosphorylation in Gle1's N-terminal low complexity cluster. Indirect immunofluorescence microscopy with the anti-Gle1-pT102 antibodies revealed that basally phosphorylated Gle1 was pre-dominantly nuclear with punctate distribution; however, under sodium arsenite-induced stress, more cytoplasmic localization was detected. Immunoprecipitation with the anti-Gle1-pT102 antibody resulted in co-isolation of Gle1-pT102 with the DEAD-box protein DDX1 in a phosphatase sensitive manner. This suggested Gle1 phosphorylation might be linked to its role in regulating DDX1 during transcription termination. Notably, whereas the total Gle1-DDX1 association was decreased when Gle1 nucleocytoplasmic shuttling was disrupted, co-isolation of Gle1-pT102 and DDX1 increased under the same conditions. Taken together, these studies demonstrated that Gle1 phosphorylation impacts its cellular distribution and potentially drives nuclear Gle1 functions in transcription termination. We propose a model wherein phosphorylation of Gle1 either reduces its nucleocytoplasmic shuttling capacity or increases its binding affinity with nuclear interaction partners., Competing Interests: Declaration of competing interest None, (Copyright © 2023 Elsevier Ltd. All rights reserved.)

With greater availability of hemp (Cannabis sativa L.) due to recent legislation, hempseed meal (HSM) should be evaluated as a potential feedstuff for livestock. The study objective was to evaluate the palatability of HSM in horses. Trial 1 used a modified 3 × 3 Latin Square design utilizing three geldings and three mares. Feeding periods (6d) consisted of two feedings/d with a washout phase (3d) before each treatment phase (3d). During treatment, horses were offered soybean meal pellets (SBM), rice bran pellets (RBP), or beet pulp pellets (BPP) in one bucket (500 g) and HSM in a second bucket (500 g) each feeding. In Trial 2, six geldings were offered 1 kg of HSM pellets over two 5-minute periods, 1 hour apart each day, with 1kg of Coastal Bermudagrass hay between offerings. Consumption of HSM in Trial 1 was greater than SBM (P = .005) and BPP (P < .001) but not different from RBP (P = .19). Consumption of HSM increased with each subsequent period (P < .001). In Trial 2, intake of HSM on d1, d2, and d3 were less than d6 (P < .05). Hay consumption was greater on d1 and d2 than d6 (P < .01). Hay consumption and HSM intake were not correlated (R 2  = 0.001). These findings indicate that HSM may be similar in palatability to RBP and more palatable than SBM and BPP. Consumption of HSM increases over time, but is not impacted by hay consumption. In equine rations, HSM may serve as an acceptable replacement to more common feedstuffs., Competing Interests: Declaration of Competing Interest The authors declare that they have no conflicts of interest., (Copyright © 2023 Elsevier Inc. All rights reserved.)

Temperature challenges are one of the leading abiotic causes of success or failure of non-native species in a novel environment, and this is particularly true for low temperatures. Establishing and reproducing in a novel thermal environment can alter survival, behavior, and traits related to fitness. It has been proposed that plasticity or adaptation of thermal tolerance may allow an introduced species to thrive, or that successful invaders may be those with a thermal breadth in their native habitat that encompasses their new environment. Here, we tested these hypotheses using native and invasive populations of Australian redback spiders (Latrodectus hasselti). We measured how exposure to temperatures common to invasive and native range habitats (exposure to 15 and 25°C, respectively) affected behavioral and life-history traits and trade-offs that may underlie fitness in an invasive population detected in 1995 in Japan and a native population from Australia. We found that the critical thermal minimum (CTmin) was higher in the invasive population from Japan than in the native population, but critical thermal maximum (CTmax) did not differ between populations. Compared to the invasive population, eggs from the native population had a longer development time and lower hatching success at 15°C. Both populations performed equally well at 25°C, as measured by egg development time and hatching success. Invasive juveniles tested at 15°C were faster to explore a novel environment and bolder compared to those tested at 25°C. In comparison, the native population showed faster average exploration, with no differences in boldness or exploration at the two development or testing temperatures. Overall, L. hasselti from Japan maintained hatching success and development across a wider temperature range than the native population, indicating greater thermal breadth and higher behavioral plasticity. These results support the importance of plasticity in thermal tolerance and behavior for a successful invasion under novel environmental temperatures., (© The Author(s) 2022. Published by Oxford University Press on behalf of the Society for Integrative and Comparative Biology.)

Gle1 is a conserved, essential regulator of DEAD-box RNA helicases, with critical roles defined in mRNA export, translation initiation, translation termination, and stress granule formation. Mechanisms that specify which, where, and when DDXs are targeted by Gle1 are critical to understand. In addition to roles for stress-induced phosphorylation and inositol hexakisphosphate binding in specifying Gle1 function, Gle1 oligomerizes via its N-terminal domain in a phosphorylation-dependent manner. However, a thorough analysis of the role for Gle1 self-association is lacking. Here, we find that Gle1 self-association is driven by two distinct regions: a coiled-coil domain and a novel 10-amino acid aggregation-prone region, both of which are necessary for proper Gle1 oligomerization. By exogenous expression in HeLa cells, we tested the function of a series of mutations that impact the oligomerization domains of the Gle1A and Gle1B isoforms. Gle1 oligomerization is necessary for many, but not all aspects of Gle1A and Gle1B function, and the requirements for each interaction domain differ. Whereas the coiled-coil domain and aggregation-prone region additively contribute to competent mRNA export and stress granule formation, both self-association domains are independently required for regulation of translation under cellular stress. In contrast, Gle1 self-association is dispensable for phosphorylation and nonstressed translation initiation. Collectively, we reveal self-association functions as an additional mode of Gle1 regulation to ensure proper mRNA export and translation. This work also provides further insight into the mechanisms underlying human gle1 disease mutants found in prenatally lethal forms of arthrogryposis., Competing Interests: Conflict of interest—The authors declare that they have no conflicts of interest with the contents of this article., (© 2020 Mason and Wente.)

Background: As the national opioid epidemic escalates, rates of the Hepatitis C (HCV) infection have similarly risen. Surgeons exposed intraoperatively secondary to sharp instrument or needle-sticks are affected both socioeconomically and physically. Current treatment strategies involve antiretroviral agents that have not been universally available. This study evaluates the current risk of surgeon exposure to HCV., Methods: CDC data regarding state-by-state HCV diagnosis reporting were combined with the plastic surgery workforce data from the ASPS. Proxy variables for exposure risk to HCV were generated for each state and compared., Results: West Virginia plastic surgeons were found to have a significantly elevated risk of exposure (60.0 versus 18.7, P < 0.0001). Their exposure risk is a notable outlier compared with the rest of the country (Risk >3 × IQR + 75th percentile). Similarly, states within the Ohio Valley were found to be at increased risk (34.8 versus 16.0, P = 0.05). States most heavily burdened by the opioid crisis were found to be at an increased risk for HCV exposure (40.8 versus 13.6, P = 0.0003)., Conclusions: Plastic surgeons employed in states within the Ohio Valley were found to be at an increased risk of exposure to HCV. Plastic surgeons operating in states severely impacted by the opioid crisis were found to be at an increased risk of exposure. These findings underscore the importance of reducing the risk in the operating room and the need for better data collection to better understand this association and mitigate the risk to the operating surgeon., Competing Interests: Disclosure: The authors have no financial interest to declare in relation to the content of this article. This research was not supported by any form of funding from grants or work for hire., (Copyright © 2020 The Authors. Published by Wolters Kluwer Health, Inc. on behalf of The American Society of Plastic Surgeons.)

Body size is an important trait linking pollinators and plants. Morphological matching between pollinators and plants is thought to reinforce pollinator fidelity, as the correct fit ensures that both parties benefit from the interaction. We investigated the influence of body size in a specialized pollination system (buzz-pollination) where bees vibrate flowers to release pollen concealed within poricidal stamens. Specifically, we explored how body size influences the frequency of buzz-pollination vibrations. Body size is expected to affect frequency as a result of the physical constraints it places on the indirect flight muscles that control the production of floral vibrations. Larger insects beat their wings less rapidly than smaller-bodied insects when flying, but whether similar scaling relationships exist with floral vibrations has not been widely explored. This is important because the amount of pollen ejected is determined by the frequency of the vibration and the displacement of a bee's thorax. We conducted a field study in three ecogeographic regions (alpine, desert, grassland) and recorded flight and floral vibrations from freely foraging bees from 27 species across four families. We found that floral vibration frequencies were significantly higher than flight frequencies, but never exceeded 400 Hz. Also, only flight frequencies were negatively correlated with body size. As a bee's size increased, its buzz ratio (floral frequency/flight frequency) increased such that only the largest bees were capable of generating floral vibration frequencies that exceeded double that of their flight vibrations. These results indicate size affects the capacity of bees to raise floral vibration frequencies substantially above flight frequencies. This may put smaller bees at a competitive disadvantage because even at the maximum floral vibration frequency of 400 Hz, their inability to achieve comparable thoracic displacements as larger bees would result in generating vibrations with lower amplitudes, and thus less total pollen ejected for the same foraging effort., Competing Interests: None declared.

Rapid expression of critical stress response factors is a key survival strategy for diseased or stressed cells. During cell stress, translation is inhibited, and a pre-existing pool of cytoplasmic mRNA-protein complexes reversibly assembles into cytoplasmic stress granules (SGs). Gle1 is a conserved modulator of RNA-dependent DEAD-box proteins required for mRNA export, translation, and stress responses. Proper Gle1 function is critical as reflected by some human diseases such as developmental and neurodegenerative disorders and some cancers linked to gle1 mutations. However, the mechanism by which Gle1 controls SG formation is incompletely understood. Here, we show that human Gle1 is regulated by phosphorylation during heat shock stress. In HeLa cells, stress-induced Gle1 hyperphosphorylation was dynamic, primarily in the cytoplasmic pool, and followed changes in translation factors. MS analysis identified 14 phosphorylation sites in the Gle1A isoform, six of which clustered in an intrinsically disordered, low-complexity N-terminal region flanking the coil-coiled self-association domain. Of note, two mitogen-activated protein kinases (MAPKs), extracellular signal-regulated kinase (ERK) and c-Jun N-terminal kinase (JNK), phosphorylated the Gle1A N-terminal domain, priming it for phosphorylation by glycogen synthase kinase 3 (GSK3). A phosphomimetic gle1A 6D variant (in which six putative Ser/Thr phosphorylation sites were substituted with Asp) perturbed self-association and inhibited DEAD-box helicase 3 (X-linked) (DDX3) ATPase activity. Expression of alanine-substituted, phosphodeficient GFP-gle1A 6A promoted SG assembly, whereas GFP-gle1A 6D enhanced SG disassembly. We propose that MAPKs and GSK3 phosphorylate Gle1A and thereby coordinate SG dynamics by altering DDX3 function., (© 2019 Aditi et al.)

Background: Orofacial clefting (OFC) is the most common developmental craniofacial malformation, and causal etiologies largely remain unknown. The opioid crisis has led to a large proportion of infants recovering from neonatal abstinence syndrome (NAS) due to in-utero narcotics exposure. We sought to characterize the prevalence of OFC in infants with NAS., Methods: This cohort study analyzed live births at our institution from 2013 to 2017 to identify any association between OFC and NAS., Results: Prevalence of OFC was 6.79 and 1.63 (per 1,000 live births) in the NAS and general population, respectively. Odds ratios for NAS patients having developed OFC, isolated cleft palate, isolated cleft lip, and combined cleft lip and palate compared with the general population were found to be 4.18 ( P = 0.001), 5.92 ( P = 0.001), 3.79 ( P = 0.05), and 2.94 ( P = 0.35), respectively. Analyses performed comparing the NAS and general populations to control for potential confounding variables influencing the NAS population yielded no significant differences with exception of in-utero exposure to physician prescribed opioids., Conclusions: Prevalence of OFC in infants with NAS was higher than the general live birth population. Isolated cleft palate and isolated cleft lip, specifically, were significantly more prevalent in NAS patients compared with the general population and were associated with in-utero opioid exposure.

Insects have evolved a diversity of hearing organs specialized to detect sounds critical for survival. We report on a unique structure on butterfly wings that enhances hearing. The Satyrini are a diverse group of butterflies occurring throughout the world. One of their distinguishing features is a conspicuous swelling of their forewing vein, but the functional significance of this structure is unknown. Here, we show that wing vein inflations function in hearing. Using the common wood nymph, Cercyonis pegala , as a model, we show that (i) these butterflies have ears on their forewings that are most sensitive to low frequency sounds (less than 5 kHz); (ii) inflated wing veins are directly connected to the ears; and (iii) when vein inflations are ablated, sensitivity to low frequency sounds is impaired. We propose that inflated veins contribute to low frequency hearing by impedance matching., (© 2018 The Author(s).)

Nocturnal insects have evolved ultrasound-sensitive hearing in response to predation pressures from echolocating insectivorous bats. Flying tympanate moths take various evasive actions when they detect bat cries, including turning away, performing a steering/zigzagging flight and ceasing flight. In general, infrequent ultrasonic pulses with low sound intensities that are emitted by distant bats evoke slight turns, whereas frequent and loud ultrasonic pulses of nearby bats evoke erratic or rapid unpredictable changes in the flight path of a moth. Flight cessation, which is a freezing response that causes the moth to passively dive (drop) to the ground, is considered the ultimate last-ditch evasive behaviour against approaching bats where there is a high predation threat. Here, we found that the crambid moth Nomophila nearctica never performed passive dives in response to frequent and loud ultrasonic pulses of >60 dB sound pressure level (SPL) that simulated the attacking echolocation call sequence of the predominant sympatric insectivorous bat Eptesicus fuscus, but rather turned away or flew erratically, regardless of the temporal structure of the stimulus. Consequently, N. nearctica is likely to survive predation by bats by taking early evasive action even when it detects the echolocation calls of sympatric bats hunting other insects at a distance. Since aerially hawking bats can track and catch erratically flying moths after targeting their prey, this early escape strategy may be common among night-flying tympanate insects., Competing Interests: The authors have declared that no competing interests exist.

The mRNA lifecycle is driven through spatiotemporal changes in the protein composition of mRNA particles (mRNPs) that are triggered by RNA-dependent DEAD-box protein (Dbp) ATPases. As mRNPs exit the nuclear pore complex (NPC) in Saccharomyces cerevisiae, this remodeling occurs through activation of Dbp5 by inositol hexakisphosphate (IP 6 )-bound Gle1. At the NPC, Gle1 also binds Nup42, but Nup42's molecular function is unclear. Here we employ the power of structure-function analysis in S. cerevisiae and human (h) cells, and find that the high-affinity Nup42-Gle1 interaction is integral to Dbp5 (hDDX19B) activation and efficient mRNA export. The Nup42 carboxy-terminal domain (CTD) binds Gle1/hGle1B at an interface distinct from the Gle1-Dbp5/hDDX19B interaction site. A nup42-CTD/gle1-CTD/Dbp5 trimeric complex forms in the presence of IP 6 . Deletion of NUP42 abrogates Gle1-Dbp5 interaction, and disruption of the Nup42 or IP 6 binding interfaces on Gle1/hGle1B leads to defective mRNA export in S. cerevisiae and human cells. In vitro, Nup42-CTD and IP 6 stimulate Gle1/hGle1B activation of Dbp5 and DDX19B recombinant proteins in similar, nonadditive manners, demonstrating complete functional conservation between humans and S. cerevisiae. Together, a highly conserved mechanism governs spatial coordination of mRNP remodeling during export. This has implications for understanding human disease mutations that perturb the Nup42-hGle1B interaction., (© 2017 John Wiley & Sons A/S. Published by John Wiley & Sons Ltd.)

Spatial release from masking (SRM) occurs when spatial separation between a signal and masker decreases masked thresholds. The mechanically-coupled ears of Ormia ochracea are specialized for hyperacute directional hearing, but the possible role of SRM, or whether such specializations exhibit limitations for sound source segregation, is unknown. We recorded phonotaxis to a cricket song masked by band-limited noise. With a masker, response thresholds increased and localization was diverted away from the signal and masker. Increased separation from 6° to 90° did not decrease response thresholds or improve localization accuracy, thus SRM does not operate in this range of spatial separations. Tympanal vibrations and auditory nerve responses reveal that localization errors were consistent with changes in peripheral coding of signal location and flies localized towards the ear with better signal detection. Our results demonstrate that, in a mechanically coupled auditory system, specialization for directional hearing does not contribute to source segregation.

Male grigs, bush crickets and crickets produce mating calls by tegminal stridulation: the scraping together of modified forewings functioning as sound generators. Bush crickets (Tettigoniidae) and crickets (Gryllinae) diverged some 240 million years ago, with each lineage developing unique characteristics in wing morphology and the associated mechanics of stridulation. The grigs (Prophalangopsidae), a relict lineage more closely related to bush crickets than to crickets, are believed to retain plesiomorphic features of wing morphology. The wing cells widely involved in sound production, such as the harp and mirror, are comparatively small, poorly delimited and/or partially filled with cross-veins. Such morphology is similarly observed in the earliest stridulating ensiferans, for which stridulatory mechanics remains poorly understood. The grigs, therefore, are of major importance to investigate the early evolutionary stages of tegminal stridulation, a critical innovation in the evolution of the Orthoptera. The aim of this study is to appreciate the degree of specialization on grig forewings, through identification of sound radiating areas and their properties. For well-grounded comparisons, homologies in wing venation (and associated areas) of grigs and bush crickets are re-evaluated. Then, using direct evidence, this study confirms the mirror cell, in association with two other areas (termed 'neck' and 'pre-mirror'), as the acoustic resonator in the grig Cyphoderris monstrosa Despite the use of largely symmetrical resonators, as found in field crickets, analogous features of stridulatory mechanics are observed between C. monstrosa and bush crickets. Both morphology and function in grigs represents transitional stages between unspecialized forewings and derived conditions observed in modern species., (© 2017. Published by The Company of Biologists Ltd.)

DNA damage and other forms of replication stress can cause replication forks to stall. Replication stress response proteins stabilize and resolve stalled forks by mechanisms that include fork remodeling to facilitate repair or bypass of damaged templates. Several enzymes including SMARCAL1, HLTF, and ZRANB3 catalyze these reactions. SMARCAL1 and HLTF utilize structurally distinct accessory domains attached to an ATPase motor domain to facilitate DNA binding and catalysis of fork remodeling reactions. Here we describe a substrate recognition domain within ZRANB3 that is needed for it to recognize forked DNA structures, hydrolyze ATP, catalyze fork remodeling, and act as a structure-specific endonuclease. Thus, substrate recognition domains are a common feature of fork remodeling, SNF2-family, DNA-dependent ATPases, and our study provides further mechanistic understanding of how these enzymes maintain genome integrity during DNA replication., (© 2016 by The American Society for Biochemistry and Molecular Biology, Inc.)

The acoustic signalling behaviour of many tree cricket species is easily observed and has been well described. Very little is known, however, about the receivers in these communication loops. The exception to this is a single Indian species (Oecanthus henryi) which employs active auditory mechanics to enhance female sensitivity to quiet sounds at male calling frequencies. In most species, male calls have been described, but whether or not sender–receiver matching is present is uncertain. Here we investigate auditory mechanics in females of the North American black-horned tree cricket (Oecanthus nigricornis). The response of the anterior tympanal membrane is nonlinear, exhibiting a lack of tuning at high amplitudes (60 dB and above) but as stimulus amplitude decreases, the membrane becomes tuned to around 4.3 kHz. The tuning of the membrane falls within the frequency range of male calls indicating sender–receiver matching at low amplitudes, which could aid localisation of the highly directional calls of males. The extent of active auditory mechanics in tympanal insects is not yet known, but this paper provides an indication that this may indeed be widespread in at least the Oecanthinae.

Recent studies have suggested that metabolic efficiency may be an important factor in male mating success when females require vigorous and/or prolonged courtship. In capital breeding animals in which a male's resource pool is fixed at adulthood the relationship between energy expenditure and courtship performance may be especially important, as males are expected to utilize their finite resources efficiently when soliciting mates. Males may benefit from being efficient, i.e., achieving a sufficiently high level of courtship signaling at low energetic cost, if it enables them to acquire mates before their limited energy reserves are depleted. We investigated the relationship between metabolic efficiency and courtship vibrational signaling in the Australian redback spider, Latrodectus hasselti, a semelparous capital breeder where males invest heavily in courtship to secure a mating. We assessed metabolic rate in a sample of males and measured two courtship components (duty cycle and amplitude) that reflected the energy content of web-borne vibrations. We then calculated two indices of metabolic efficiency for these courtship properties. There was a quadratic relationship between mass and duty cycle such that the highest duty cycle signals were performed by males having intermediate mass. Furthermore, intermediate-mass males were also the most metabolically efficient. Prolonged courtship is necessary in L. hasselti for successful mating, and the results of this study suggest that intermediate-mass males are superior courters because they utilize their finite resource pool most efficiently to produce high energy vibrational signals., (Copyright © 2014 Elsevier Ltd. All rights reserved.)

SMARCAL1, a DNA remodeling protein fundamental to genome integrity during replication, is the only gene associated with the developmental disorder Schimke immuno-osseous dysplasia (SIOD). SMARCAL1-deficient cells show collapsed replication forks, S-phase cell cycle arrest, increased chromosomal breaks, hypersensitivity to genotoxic agents, and chromosomal instability. The SMARCAL1 catalytic domain (SMARCAL1(CD)) is composed of an SNF2-type double-stranded DNA motor ATPase fused to a HARP domain of unknown function. The mechanisms by which SMARCAL1 and other DNA translocases repair replication forks are poorly understood, in part because of a lack of structural information on the domains outside of the common ATPase motor. In the present work, we determined the crystal structure of the SMARCAL1 HARP domain and examined its conformation and assembly in solution by small angle X-ray scattering. We report that this domain is conserved with the DNA mismatch and damage recognition domains of MutS/MSH and NER helicase XPB, respectively, as well as with the putative DNA specificity motif of the T4 phage fork regression protein UvsW. Loss of UvsW fork regression activity by deletion of this domain was rescued by its replacement with HARP, establishing the importance of this domain in UvsW and demonstrating a functional complementarity between these structurally homologous domains. Mutation of predicted DNA-binding residues in HARP dramatically reduced fork binding and regression activities of SMARCAL1(CD). Thus, this work has uncovered a conserved substrate recognition domain in DNA repair enzymes that couples ATP-hydrolysis to remodeling of a variety of DNA structures, and provides insight into this domain's role in replication fork stability and genome integrity.

SWI/SNF-related, matrix-associated, actin-dependent regulator of chromatin, subfamily A-like1 (SMARCAL1) is a recently identified DNA damage response protein involved in remodeling stalled replication forks. The eukaryotic single-strand DNA binding protein replication protein A (RPA) recruits SMARCAL1 to stalled forks in vivo and facilitates regression of forks containing leading strand gaps. Both activities are mediated by a direct interaction between an RPA binding motif (RBM) at the N-terminus of SMARCAL1 and the C-terminal winged-helix domain of the RPA 32 kDa subunit (RPA32C). Here we report a biophysical and structural characterization of the SMARCAL1-RPA interaction. Isothermal titration calorimetry and circular dichroism spectroscopy revealed that RPA32C binds SMARCAL1-RBM with a Kd of 2.5 μM and induces a disorder-to-helix transition. The crystal structure of RPA32C was refined to 1.4 Å resolution, and the SMARCAL1-RBM binding site was mapped on the structure on the basis of nuclear magnetic resonance chemical shift perturbations. Conservation of the interaction surface to other RBM-containing proteins allowed construction of a model for the RPA32C/SMARCAL1-RBM complex. The implications of our results are discussed with respect to the recruitment of SMARCAL1 and other DNA damage response and repair proteins to stalled replication forks.

Buzz-pollination is a plant strategy that promotes gamete transfer by requiring a pollinator, typically bees (Hymenoptera: Apoidea), to vibrate a flower's anthers in order to extract pollen. Although buzz-pollination is widespread in angiosperms with over 20,000 species using it, little is known about the functional connection between natural variation in buzzing vibrations and the amount of pollen that can be extracted from anthers. We characterized variability in the vibrations produced by Bombus terrestris bumblebees while collecting pollen from Solanum rostratum (Solanaceae), a buzz-pollinated plant. We found substantial variation in several buzzing properties both within and among workers from a single colony. As expected, some of this variation was predicted by the physical attributes of individual bumblebees: heavier workers produced buzzes of greater amplitude. We then constructed artificial "pollination buzzes" that varied in three parameters (peak frequency, peak amplitude, and duration), and stimulated S. rostratum flowers with these synthetic buzzes to quantify the relationship between buzz properties and pollen removal. We found that greater amplitude and longer duration buzzes ejected substantially more pollen, while frequency had no directional effect and only a weak quadratic effect on the amount of pollen removed. These findings suggest that foraging bumblebees may improve pollen collection by increasing the duration or amplitude of their buzzes. Moreover, given that amplitude is positively correlated with mass, preferential foraging by heavier workers is likely to result in the largest pollen yields per bee, and this could have significant consequences for the success of a colony foraging on buzz-pollinated flowers.

Stalled replication forks are sources of genetic instability. Multiple fork-remodeling enzymes are recruited to stalled forks, but how they work to promote fork restart is poorly understood. By combining ensemble biochemical assays and single-molecule studies with magnetic tweezers, we show that SMARCAL1 branch migration and DNA-annealing activities are directed by the single-stranded DNA-binding protein RPA to selectively regress stalled replication forks caused by blockage to the leading-strand polymerase and to restore normal replication forks with a lagging-strand gap. We unveil the molecular mechanisms by which RPA enforces SMARCAL1 substrate preference. E. coli RecG acts similarly to SMARCAL1 in the presence of E. coli SSB, whereas the highly related human protein ZRANB3 has different substrate preferences. Our findings identify the important substrates of SMARCAL1 in fork repair, suggest that RecG and SMARCAL1 are functional orthologs, and provide a comprehensive model of fork repair by these DNA translocases., (Copyright © 2013 The Authors. Published by Elsevier Inc. All rights reserved.)

SMARCAL1 (SWI/SNF-related, matrix-associated, actin-dependent regulator of chromatin, subfamily A-like1) maintains genome integrity during DNA replication. Here we investigated its mechanism of action. We found that SMARCAL1 travels with elongating replication forks, and its absence leads to MUS81-dependent double-strand break formation. Binding to specific nucleic acid substrates activates SMARCAL1 activity in a reaction that requires its HARP2 (Hep-A-related protein 2) domain. Homology modeling indicates that the HARP domain is similar in structure to the DNA-binding domain of the PUR proteins. Limited proteolysis, small-angle X-ray scattering, and functional assays indicate that the core enzymatic unit consists of the HARP2 and ATPase domains that fold into a stable structure. Surprisingly, SMARCAL1 is capable of binding three-way and four-way Holliday junctions and model replication forks that lack a designed ssDNA region. Furthermore, SMARCAL1 remodels these DNA substrates by promoting branch migration and fork regression. SMARCAL1 mutations that cause Schimke immunoosseous dysplasia or that inactivate the HARP2 domain abrogate these activities. These results suggest that SMARCAL1 continuously surveys replication forks for damage. If damage is present, it remodels the fork to promote repair and restart. Failures in the process lead to activation of an alternative repair mechanism that depends on MUS81-catalyzed cleavage of the damaged fork.

Protein glycosylation (e.g., N-linked glycosylation) is known to play an essential role in both cellular functions and secretory pathways; however, our knowledge of in vivo N-glycosylated sites is very limited for the majority of fungal organisms including Aspergillus niger. Herein, we present the first extensive mapping of N-glycosylated sites in A. niger by applying an optimized solid phase glycopeptide enrichment protocol using hydrazide-modified magnetic beads. The enrichment protocol was initially optimized using both mouse blood plasma and A. niger secretome samples, and it was demonstrated that the protein-level enrichment protocol offered superior performance over the peptide-level protocol. The optimized protocol was then applied to profile N-glycosylated sites from both the secretome and whole cell lysates of A. niger. A total of 847 N-glycosylated sites from 330 N-glycoproteins (156 proteins from the secretome and 279 proteins from whole cells) were confidently identified by LC-MS/MS. The identified N-glycoproteins in the whole cell lysate were primarily localized in the plasma membrane, endoplasmic reticulum, Golgi apparatus, lysosome, and storage vacuoles, supporting the important role of N-glycosylation in the secretory pathways. In addition, these glycoproteins are involved in many biological processes including gene regulation, signal transduction, protein folding and assembly, protein modification, and carbohydrate metabolism. The extensive coverage of N-glycosylated sites and the observation of partial glycan occupancy on specific sites in a number of enzymes provide important initial information for functional studies of N-linked glycosylation and their biotechnological applications in A. niger.

Food insecurity is associated with decreased nutrient intake and poor health and possibly low bone mass in children. The purpose of this study was to formally investigate the relationship of diet, bone mass, and food insecurity among children aged 8-19 y (n = 5270). The data used in this cross-sectional study were drawn from children participating in the NHANES 2001-2004. Data were collected from homes and NHANES mobile examination centers across the United States. Food security status was classified using the US Children's Food Security Scale and the US Household Food Security Scale. Dietary measures were quantified by 24-h dietary recall and bone mineral content (BMC) was determined with whole body DXA. Results indicated that males 8-11 y from households with food insecurity among children were 2.5 times [OR = 2.5 (95% CI = 1.1-5.8)] more likely to have fewer than the USDA Food Guide recommended servings of dairy foods, 2.3 times [OR = 2.3 (95% CI = 1.3-4.0)] more likely to have less than the estimated average requirement for calcium intake, and more likely to have a significantly lower estimated total body (P = 0.04), trunk (P = 0.05), lumbar spine (P = 0.02), pelvis (P = 0.05), and left arm (P = 0.05) BMC compared with males 8-11 y old from households with food security among children. Calcium-related dietary factors and BMC did not differ among females by food security status. These results are evidence that health disparities persist among 8- to 11-y-old, food-insecure boys. Successful interventions to improve diet and bone health and reduce food insecurity among children are a continuing need in the United States.

ATR kinase is a critical upstream regulator of the checkpoint response to various forms of DNA damage. Previous studies have shown that ATR is recruited via its binding partner ATR-interacting protein (ATRIP) to replication protein A (RPA)-covered single-stranded DNA (RPA-ssDNA) generated at sites of DNA damage where ATR is then activated by TopBP1 to phosphorylate downstream targets including the Chk1 signal transducing kinase. However, this critical feature of the human ATR-initiated DNA damage checkpoint signaling has not been demonstrated in a defined system. Here we describe an in vitro checkpoint system in which RPA-ssDNA and TopBP1 are essential for phosphorylation of Chk1 by the purified ATR-ATRIP complex. Checkpoint defective RPA mutants fail to activate ATR kinase in this system, supporting the conclusion that this system is a faithful representation of the in vivo reaction. Interestingly, we find that an alternative form of RPA (aRPA), which does not support DNA replication, can substitute for the checkpoint function of RPA in vitro, thus revealing a potential role for aRPA in the activation of ATR kinase. We also find that TopBP1 is recruited to RPA-ssDNA in a manner dependent on ATRIP and that the N terminus of TopBP1 is required for efficient recruitment and activation of ATR kinase.

Replication protein A (RPA) is a single-stranded DNA-binding complex that is essential for DNA replication, repair, and recombination in eukaryotic cells. In addition to this canonical complex, we have recently characterized an alternative replication protein A complex (aRPA) that is unique to primates. aRPA is composed of three subunits: RPA1 and RPA3, also present in canonical RPA, and a primate-specific subunit RPA4, homologous to canonical RPA2. aRPA has biochemical properties similar to those of the canonical RPA complex but does not support DNA replication. We describe studies that aimed to identify what properties of aRPA prevent it from functioning in DNA replication. We show aRPA has weakened interaction with DNA polymerase alpha (pol alpha) and that aRPA is not able to efficiently stimulate DNA synthesis by pol alpha on aRPA-coated DNA. Additionally, we show that aRPA is unable to support de novo priming by pol alpha. Because pol alpha activity is essential for both initiation and Okazaki strand synthesis, we conclude that the inability of aRPA to support pol alpha loading causes aRPA to be defective in DNA replication. We also show that aRPA stimulates synthesis by DNA polymerase alpha in the presence of PCNA and RFC. This indicates that aRPA can support extension of DNA strands by DNA polymerase partial differential. This finding along with the previous observation that aRPA supports early steps of nucleotide excision repair and recombination indicates that aRPA can support DNA repair synthesis that requires polymerase delta, PCNA, and RFC and support a role for aRPA in DNA repair.

In many animal taxa, prior contest experience affects future performance such that winning increases the chances of winning in the future (winner effect) and losing increases the chances of losing in the future (loser effect). It is, however, not clear whether this pattern typically arises from experience effects on actual or perceived fighting ability (or both). In this study, we looked at winner and loser effects in the jumping spider Phidippus clarus. We assigned winning or losing experience to spiders and tested them against opponents of similar fighting ability in subsequent contests at 1-, 2-, 5-, and 24-h intervals. We examined the strength of winner and loser effects, how long effects persist, as well as how experience affected perceived and actual fighting ability. Our results demonstrate that winner and loser effects are of approximately the same magnitude, although loser effects last longer than winner effects. Our results also demonstrate that previous experience alters actual fighting ability because both the assessment and escalation periods were affected by experience. We suggest that the retention time of experience effects depends on expected encounter rates as well as other behavioral and ecological factors. In systems with short breeding seasons and/or rapidly fluctuating populations, context-dependent retention of experience effects may allow males to track their status relative to the fluctuating fighting ability of local competitors without paying the costs necessary to recall or assess individual competitors.

Replication protein A (RPA) is a heterotrimeric protein complex required for a large number of DNA metabolic processes, including DNA replication and repair. An alternative form of RPA (aRPA) has been described in which the RPA2 subunit (the 32-kDa subunit of RPA and product of the RPA2 gene) of canonical RPA is replaced by a homologous subunit, RPA4. The normal function of aRPA is not known; however, previous studies have shown that it does not support DNA replication in vitro or S-phase progression in vivo. In this work, we show that the RPA4 gene is expressed in normal human tissues and that its expression is decreased in cancerous tissues. To determine whether aRPA plays a role in cellular physiology, we investigated its role in DNA repair. aRPA interacted with both Rad52 and Rad51 and stimulated Rad51 strand exchange. We also showed that, by using a reconstituted reaction, aRPA can support the dual incision/excision reaction of nucleotide excision repair. aRPA is less efficient in nucleotide excision repair than canonical RPA, showing reduced interactions with the repair factor XPA and no stimulation of XPF-ERCC1 endonuclease activity. In contrast, aRPA exhibits higher affinity for damaged DNA than canonical RPA, which may explain its ability to substitute for RPA in the excision step of nucleotide excision repair. Our findings provide the first direct evidence for the function of aRPA in human DNA metabolism and support a model for aRPA functioning in chromosome maintenance functions in nonproliferating cells.

Background: Food insecurity, a condition of low or very low food security, is associated with decreased nutrient intake and poor health, which can lead to nutrient deficiency in children, including iron deficiency and iron deficiency anemia., Objective: The purpose of this study was to formally investigate the current relation of iron status and food security status among children aged 3-19 y (n = 11,247)., Design: Participants of the National Health and Nutrition Examination Survey 1999-2004 were classified for food security status by using the US Children's Food Security Scale and the US Household Food Security Scale. Iron deficiency was defined as > or =2 abnormal values for transferrin saturation, serum ferritin, and erythrocyte protoporphyrin, with the addition of abnormal hemoglobin to classify iron deficiency anemia., Results: The odds of iron deficiency anemia among children aged 12-15 y were 2.95 times (95% CI: 1.18, 7.37; P = 0.02) those for children in households with food insecurity among children compared with children in households with food security among children., Conclusions: The results of this study indicate a continuing need for successful interventions to reduce iron deficiency anemia among food-insecure children and to improve food security among children.

FANCJ mutations are genetically linked to the Fanconi anemia complementation group J and predispose individuals to breast cancer. Understanding the role of FANCJ in DNA metabolism and how FANCJ dysfunction leads to tumorigenesis requires mechanistic studies of FANCJ helicase and its protein partners. In this work, we have examined the ability of FANCJ to unwind DNA molecules with specific base damage that can be mutagenic or lethal. FANCJ was inhibited by a single thymine glycol, but not 8-oxoguanine, in either the translocating or nontranslocating strands of the helicase substrate. In contrast, the human RecQ helicases (BLM, RECQ1, and WRN) display strand-specific inhibition of unwinding by the thymine glycol damage, whereas other DNA helicases (DinG, DnaB, and UvrD) are not significantly inhibited by thymine glycol in either strand. In the presence of replication protein A (RPA), but not Escherichia coli single-stranded DNA-binding protein, FANCJ efficiently unwound the DNA substrate harboring the thymine glycol damage in the nontranslocating strand; however, inhibition of FANCJ helicase activity by the translocating strand thymine glycol was not relieved. Strand-specific stimulation of human RECQ1 helicase activity was also observed, and RPA bound with high affinity to single-stranded DNA containing a single thymine glycol. Based on the biochemical studies, we propose a model for the specific functional interaction between RPA and FANCJ on the thymine glycol substrates. These studies are relevant to the roles of RPA, FANCJ, and other DNA helicases in the metabolism of damaged DNA that can interfere with basic cellular processes of DNA metabolism.

In the field, phenotypic determinants of competitive success are not always absolute. For example, contest experience may alter future competitive performance. As future contests are not determined solely on phenotypic attributes, prior experience could also potentially alter phenotype-fitness associations. In this study, we examined the influence of single and multiple experiences on contest outcomes in the jumping spider Phidippus clarus. We also examined whether phenotype-fitness associations altered as individuals gained more experience. Using both size-matched contests and a tournament design, we found that both winning and losing experience affected future contest success; males with prior winning experience were more likely to win subsequent contests. Although experience was a significant determinant of success in future contests, male weight was approximately 1.3 times more important than experience in predicting contest outcomes. Despite the importance of experience in determining contest outcomes, patterns of selection did not change between rounds. Overall, our results show that experience can be an important determinant in contest outcomes, even in short-lived invertebrates, and that experience alone is unlikely to alter phenotype-fitness associations.

Objective: To determine the effect of Food Stamp Nutrition Education (FSNE) in Indiana on participants' food insecurity and food insufficiency., Design: A single-blind randomized design. A randomized experimental group completed 5 FSNE lessons as an intervention between a pre- and posttest, whereas a control group completed a pre- and posttest without FSNE intervention., Setting: Client homes and community locations in 24 Indiana counties., Participants: Female head-of-household participants >or= 18 years old; n = 219., Intervention: FSNE lessons targeting food insecurity and nutrition., Main Outcome Measures: Dependent variables food insecurity and food insufficiency were quantified with the 6-item United States Household Food Security Scale and United States Department of Agriculture Food Insufficiency Question, respectively. The independent variable was the randomly assigned treatment group., Analysis: Participants' characteristics were compared with chi-square analysis. Analyses of covariance models were constructed to find the effect of treatment group on food insecurity and food insufficiency. Significance indicated at P