Temporal Variation in Decisions about Parental Care in Bluegill, Lepomis macrochirus

Parental investment theory states that an individual will trade‐off present and future reproductive potential to maximize lifetime reproductive success. Only when parental care is costly in terms of reduced future reproductive potential should individuals be sensitive to changes in the value of current offspring and adjust their care. Here, we examine temporal variation in parental care decision‐making in bluegill (Lepomis macrochirus), in which care is provided by males called ‘parentals’. Previous research has shown that parentals that nest early in the breeding season are in higher energetic condition than those that nest later, and early nesting males appear not to pay an opportunity cost to their care in terms of reduced future reproductive potential. Early nesting males also may have higher paternity in their broods than later nesting males. To examine the parental care decisions made by early and mid‐season nesting parentals, we experimentally reduced males’ perceived paternity by swapping eggs between nests. We found that experimental males that nested early in the breeding season adjusted their brood defence behaviour similarly to control males, which had sham egg swaps performed. Conversely, experimental males that nested mid‐season significantly decreased their brood defence behaviour after the manipulation as compared with control males. Thus, unlike mid‐season nesting males, early nesting males appear relatively insensitive to changes in brood value (paternity), possibly because early nesting males pay little cost in terms of reduced future reproductive potential to providing full care or because these males have a predisposition to high paternity.     

Effect of the major repeat sequence on mitotic recombination in Candida albicans

The major repeat sequence (MRS) is known to play a role in karyotypic variation in Candida albicans. The MRS affects karyotypic variation by expanding and contracting internal repeats, by altering the frequency of chromosome loss, and by serving as a hotspot for chromosome translocation. We proposed that the effects of the MRS on translocation could be better understood by examination of the effect of the MRS on a similar event, mitotic recombination between two chromosome homologs. We examined the frequency of mitotic recombination across an MRS of average size (approximately 50 kb) as well as the rate of recombination in a 325-kb stretch of DNA adjacent to the MRS. Our results indicate that mitotic recombination frequencies across the MRS were not enhanced compared to the frequencies measured across the 325-kb region adjacent to the MRS. Mitotic recombination events were found to occur throughout the 325-kb region analyzed as well as within the MRS itself. This analysis of mitotic recombination frequencies across a large portion of chromosome 5 is the first large-scale analysis of mitotic recombination done in C. albicans and indicates that mitotic recombination frequencies are similar to the rates found in Saccharomyces cerevisiae.     

Signaling during lens regeneration

The newt is one of the few organisms that is able to undergo lens regeneration as an adult. This review will examine the signaling pathways that are involved in this amazing phenomenon. In addition to outlining the current research involved in elucidating the key signaling molecules in lens regeneration, we will also highlight some of the similarities and differences between lens regeneration and development.     

Nuclear egress of pseudorabies virus capsids is enhanced by a subspecies of the large tegument protein that is lost upon cytoplasmic maturation

Herpesviruses morphogenesis occurs stepwise both temporally and spatially, beginning in the nucleus and concluding with the emergence of an extracellular virion. The mechanisms by which these viruses interact with and penetrate the nuclear envelope and subsequent compartments of the secretory pathway remain poorly defined. In this report, a conserved viral protein (VP1/2; pUL36) that directs cytoplasmic stages of egress is identified to have multiple isoforms. Of these, a novel truncated VP1/2 species translocates to the nucleus and assists the transfer of DNA-containing capsids to the cytoplasm. The capsids are handed off to full-length VP1/2, which replaces the nuclear isoform on the capsids and is required for the final cytoplasmic stages of viral particle maturation. These results document that distinct VP1/2 protein species serve as effectors of nuclear and cytoplasmic egress.     

Single nucleotide polymorphisms in the imprinted bovine insulin-like growth factor 2 receptor gene (IGF2R) are associated with body size traits in Irish Holstein-Friesian cattle

The regulation of the bioavailability of insulin‐like growth factors (IGFs) is critical for normal mammalian growth and development. The imprinted insulin‐like growth factor 2 receptor gene (IGF2R) encodes a transmembrane protein receptor that acts to sequester and degrade excess circulating insulin‐like growth factor 2 (IGF‐II) – a potent foetal mitogen – and is considered an important inhibitor of growth. Consequently, IGF2R may serve as a candidate gene underlying important growth‐ and body‐related quantitative traits in domestic mammalian livestock. In this study, we have quantified genotype–phenotype associations between three previously validated intronic bovine IGF2R single nucleotide polymorphisms (SNPs) (IGF2R:g.64614T>C, IGF2R:g.65037T>C and IGF2R:g.86262C>T) and a range of performance traits in 848 progeny‐tested Irish Holstein‐Friesian artificial insemination sires. Notably, all three polymorphisms analysed were associated (P ≤ 0.05) with at least one of a number of performance traits related to animal body size: angularity, body depth, chest width, rump width, and animal stature. In addition, the C‐to‐T transition at the IGF2R:g.65037T>C polymorphism was positively associated with cow carcass weight and angularity. Correction for multiple testing resulted in the retention of two genotype–phenotype associations (animal stature and rump width). None of the SNPs analysed were associated with any of the milk traits examined. Analysis of pairwise r² measures of linkage disequilibrium between all three assayed SNPs ranged between 0.41 and 0.79, suggesting that some of the observed SNP associations with performance may be independent. To our knowledge, this is one of the first studies demonstrating associations between IGF2R polymorphisms and growth‐ and body‐related traits in cattle. These results also support the increasing body of evidence that imprinted genes harbour polymorphisms that contribute to heritable variation in phenotypic traits in domestic livestock species.     

Effects of red bull energy drink on repeated sprint performance in women athletes

Energy drinks are frequently consumed by athletes prior to competition to improve performance. This study examined the effect of Red Bull™ on repeated sprint performance in women athletes. Fifteen collegiate soccer players participated, with mean age, height, and body mass equal to 19.5 ± 1.1 year, 168.4 ± 5.8 cm, and 63.4 ± 6.1 kg, respectively. After performing a familiarization trial, subjects performed three sets of eight bouts of the modified t test after ingestion of 255 mL of placebo or Red Bull 1 h pre-exercise in a randomized, placebo-controlled crossover design. Throughout testing, sprint time, heart rate (HR), and rating of perceived exertion (RPE) were continuously obtained. Repeated measures analysis of variance was used to examine differences in variables between drink conditions. Across athletes, t test time ranged from 10.4 to 12.7 s. Mean sprint time was similar (p > 0.05) between Red Bull (11.31 ± 0.61 s) and placebo (11.35 ± 0.61 s). HR and RPE increased (p < 0.05) during the bouts, but there was no effect (p > 0.05) of Red Bull on either variable versus placebo. Findings indicate that 255 mL of Red Bull containing 1.3 mg/kg of caffeine and 1 g of taurine does not alter repeated sprint performance, RPE, or HR in women athletes versus placebo. One serving of this energy drink provides no ergogenic benefit for women athletes engaging in sprint-based exercise.     

High density diffusion-free nanowell arrays

Proteomics aspires to elucidate the functions of all proteins. Protein microarrays provide an important step by enabling high-throughput studies of displayed proteins. However, many functional assays of proteins include untethered intermediates or products, which could frustrate the use of planar arrays at very high densities because of diffusion to neighboring features. The nucleic acid programmable protein array (NAPPA) is a robust in situ synthesis method for producing functional proteins just-in-time, which includes steps with diffusible intermediates. We determined that diffusion of expressed proteins led to cross-binding at neighboring spots at very high densities with reduced interspot spacing. To address this limitation, we have developed an innovative platform using photolithographically etched discrete silicon nanowells and used NAPPA as a test case. This arrested protein diffusion and cross-binding. We present confined high density protein expression and display, as well as functional protein-protein interactions, in 8000 nanowell arrays. This is the highest density of individual proteins in nanovessels demonstrated on a single slide. We further present proof of principle results on ultrahigh density protein arrays capable of up to 24000 nanowells on a single slide.     

IgE and mast cells in allergic disease

Immunoglobulin E (IgE) antibodies and mast cells have been so convincingly linked to the pathophysiology of anaphylaxis and other acute allergic reactions that it can be difficult to think of them in other contexts. However, a large body of evidence now suggests that both IgE and mast cells are also key drivers of the long-term pathophysiological changes and tissue remodeling associated with chronic allergic inflammation in asthma and other settings. Such potential roles include IgE-dependent regulation of mast-cell functions, actions of IgE that are largely independent of mast cells and roles of mast cells that do not directly involve IgE. In this review, we discuss findings supporting the conclusion that IgE and mast cells can have both interdependent and independent roles in the complex immune responses that manifest clinically as asthma and other allergic disorders.     

Are parents’ working patterns associated with their child’s sleep? An analysis of dualparent families in Australia

Insufficient sleep in children predicts emotional and behavioral problems, poorer school performance, and health problems. Child sleep durations have declined in recent decades, suggesting a need to identify and understand predictors of short sleep. The present study investigated whether aspects of parental employment (i.e. parental work hours, and non-standard work hours) were associated with sleep in children. Data collected from 2477 children aged 6-7 years as part of the Longitudinal Study of Australian Children were used in this paper. Child sleep duration, bedtimes, and wake times were determined from parent self-report using time-use diaries. Parents completed a survey assessing their work patterns as well as a range of other demographic and social factors. The results indicated that long mother work hours were associated with later bedtimes and increased odds of <9.5 h sleep in children. Long father work hours were associated with earlier waketimes, earlier bedtimes, and reduced odds of long sleep. Non-standard work hours were associated with longer sleep and earlier bedtimes. The present results indicate the need to develop strategies to limit any adverse effects of parental work on child sleep, perhaps by promoting earlier and regular bedtimes. These findings warrant further investigation given the importance of sleep in healthy child development.