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Describes experiments suitable for introducing use of radioisotopes in biology. Includes demonstrations of tracing food chains, uptake of ions by plants, concentration of elements by insects, tracing photosynthetic reactions, activation analysis of copper, and somatic and genetic effects. Uses autoradiographic and counting techniques. (AL)

A 4-year-old boy presented with his mother to genetics in the 1980s, with a family history (FH) of macrocephaly and intellectual disability (ID). He remained undiagnosed until his mother developed multiple cancers and was diagnosed with Cowden syndrome (CS) in 2017, a rare, multisystem cancer predisposition syndrome. CS was then confirmed in multiple family members. Clinical examination revealed potentially novel features; gingival enlargement, dental abnormalities and joint hyperextensibility. These features could contribute to revised PTEN hamartoma tumour syndrome, National Comprehensive Cancer Network, minor diagnostic criteria. The paediatric CS phenotype is still emerging and features expressed in this family during childhood could potentially aid paediatric diagnosis. This case reminds clinicians to seek genetic input for PTEN testing when macrocephaly is identified alongside, a personal or FH of ID, early-onset tumours (especially breast, bowel or thyroid) or multiple tumours. Thus detailed FH is pivotal to earlier CS diagnosis and improved patient outcomes.

Rugby union, alongside other collision and contact sports, faces ever mounting pressure from increased recognition of concussive injuries and the risks they present to athletes, both in the short-term and long-term. Here, the media is a central component of increasing pressure for cultural change. This research analysed data from 524 self-selected survey respondents to examine rugby union fans’ and stakeholders’ perceptions of media portrayal of concussion and how it might influence their own perceptions. We found evidence of a complex and heterogenous relationship between perceptions of masculinity, views and attitudes toward mass media, and degree of involvement in rugby union. Specifically, partisans of the sport generally saw mass media as hostile, with coverage biased against rugby, allowing them to manufacture doubt regarding risk information, as well as maintaining involvement in the sport. We conclude that critical commentaries from the media have the ability to challenge masculinities around concussion. Refereed/Peer-reviewed

Complex I deficiency, the most common respiratory chain defect, is genetically heterogeneous: mutations in 8 nuclear and 7 mitochondrial DNA genes encoding complex I subunits have been described. However, these genes account for disease in only a minority of complex I–deficient patients. We investigated whether there may be an unknown common gene by performing functional complementation analysis of cell lines from 10 unrelated patients. Two of the patients were found to have mitochondrial DNA mutations. The other 8 represented 7 different (nuclear) complementation groups, all but 1 of which showed abnormalities of complex I assembly. It is thus unlikely that any one unknown gene accounts for a large proportion of complex I cases. The 2 patients sharing a nuclear complementation group had a similar abnormal complex I assembly profile and were studied further by homozygosity mapping, chromosome transfers, and microarray expression analysis. NDUFS6, a complex I subunit gene not previously associated with complex I deficiency, was grossly underexpressed in the 2 patient cell lines. Both patients had homozygous mutations in this gene, one causing a splicing abnormality and the other a large deletion. This integrated approach to gene identification offers promise for identifying other unknown causes of respiratory chain disorders.

While cancers evolve during disease progression and in response to therapy, temporal dynamics remain difficult to study in humans due to the lack of consistent barcodes marking individual clones in vivo. We employ mitochondrial single-cell assay for transposase-accessible chromatin with sequencing to profile 163,279 cells from 9 patients with chronic lymphocytic leukemia (CLL) collected across disease course and utilize mitochondrial DNA (mtDNA) mutations as natural genetic markers of cancer clones. We observe stable propagation of mtDNA mutations over years in the absence of strong selective pressure, indicating clonal persistence, but dramatic changes following tight bottlenecks, including disease transformation and relapse posttherapy, paralleled by acquisition of copy-number variants and changes in chromatin accessibility and gene expression. Furthermore, we link CLL subclones to distinct chromatin states, providing insight into nongenetic sources of relapse. mtDNA mutations thus mirror disease history and provide naturally occurring genetic barcodes to enable patient-specific study of cancer subclonal dynamics.Significance:Single-cell multi-omic profiling of CLL reveals the utility of somatic mtDNA mutations as in vivo barcodes, which mark subclones that can evolve over time along with changes in accessible chromatin and gene expression profiles to capture dynamics of disease evolution.See related commentary by Hilton and Scott, p. 2965.This article is highlighted in the In This Issue feature, p. 2945

BACKGROUND Both M and N alleles encode antigens on Glycophorin A (GPA), a red blood cell (RBC) surface sialoglycoprotein. Interaction between RBC GPA and leukocyte surface lectins may downregulate their activation. The current study investigates if RBC autoantibodies against GPA, such as auto-anti-M/N, prime an activated phenotype in peripheral blood leukocytes. METHODS Leukocyte activation was assessed in whole blood from patients with auto-anti-GPA (anti-M/N) and compared to those with allo-anti-M/N and healthy subjects. Control samples from healthy subjects with no antibodies incubated in vitro with either anti-GPA or anti-Rh were analyzed for neutrophil and monocyte surface activation marker expression, reactive oxygen species (ROS) content, and formation of aggregates with RBCs. Samples incubated with an IgG1 isotype antibody served as controls. RESULTS Ex vivo, neutrophil CD66b and monocyte CD63 surface expression was increased in patients with auto-anti-M/N compared to those with allo anti-M/N (p = .1757; p = .0698) and to healthy subjects (p = .0186; p = .013). In vitro, neutrophil CD66b and monocyte CD63 surface expression was increased following incubation with anti-GPA compared to anti-Rh (p = .0003; p = .0328) and isotype control (p = .000; p = .0062). Intracellular ROS content increased in both neutrophils and monocytes incubated with anti-GPA compared to anti-Rh (p = .0012; p = .0693) and isotype control (p = .001; p = .0021). Percentage of neutrophil-RBC aggregates was decreased when incubated with anti-GPA compared to isotype control (p

For capital-breeding insects, all resources available for adult metabolic needs are accumulated during larval feeding. Therefore, body size at adult eclosion represents the total energetic capacity of the individual. For female capital breeders, body size is strongly correlated with lifetime fecundity, while in males, body size, which correlates with fitness, is less understood. In capital-breeding species with wingless, flightless, or dispersal-limited females, flight potential for male Lepidoptera has important implications for mate-finding and may be correlated with body size. At low population densities, failure to mate has been identified as an important Allee effect and can drive the success or failure of invasive species at range edges and in species of conservation concern. Th capital-breeding European subspecies of Lymantria dispar (L.), was introduced to North America in 1869 and now ranges across much of eastern North America. In L. dispar, females are flightless and mate-finding is entirely performed by males. We quantified male L. dispar flight capacity and propensity relative to morphological and physiological characteristics using fixed-arm flight mills. A range of male body sizes was produced by varying the protein content of standard artificial diets while holding other dietary components constant. Wing length, a proxy for body size, relative thorax mass, and forewing aspect were all important predictors of total flight distance and maximum speed. These results have important implications for mate-finding and invasion dynamics in L. dispar and may apply broadly to other capital-breeding insects.

The endosymbiotic bacterium Wolbachia pipientis confers RNA virus refractoriness in Drosophila and Aedes mosquitoes. Questions remain about the Wolbachia-virus restriction phenotype and how extensive this phenomenon may be within other arthropods. Here, we generated two Spodoptera frugiperda cell lines stably transinfected with two strains of Wolbachia, wAlbB and wMelPop-CLA. Despite the high density of Wolbachia in stably infected Sf9 cells, RT-PCR indicated the presence of the negative-sense RNA virus Spodoptera frugiperda rhabdovirus (SfRV) in Wolbachia-infected and uninfected cell lines. No differences in the replication of SfRV between Sf9 and Wolbachia-infected cells was found. RNA-Seq analysis of the parental Sf9 cells supported SfRV's presence in these cells with abundant 20 nt virus-derived small RNAs indicating active replication of SfRV in these cells. Overall, this study supports a growing body of evidence that Wolbachia does not restrict negative-sense RNA viruses and generates an in vitro model to examine Lepidoptera-Wolbachia virus interactions.

Hop powdery mildew, caused by the ascomycete fungus Podosphaera macularis, is a consistent threat to sustainable hop production. The pathogen utilizes two reproductive strategies for overwintering and perennation: (i) asexual vegetative hyphae on dormant buds that emerge the following season as infected shoots; and (ii) sexual ascocarps (chasmothecia), which are discharged during spring rain events. We demonstrate that P. macularis chasmothecia, in the absence of any asexual P. macularis growth forms, are a viable overwintering source capable of causing early season infection two to three orders of magnitude greater than that reported for perennation via asexual growth. Two epidemiological models were defined that describe (i) temperature-driven maturation of P. macularis chasmothecia; and (ii) ascosporic discharge in response to duration of leaf wetness and prevailing temperatures. P. macularis ascospores were confirmed to be infectious at temperatures ranging from 5 to 20°C. The organism’s chasmothecia were also found to adhere tightly to the host tissue on which they formed, suggesting that these structures likely overwinter wherever hop tissue senesces within a hop yard. These observations suggest that existing early season disease management practices are especially crucial to controlling hop powdery mildew in the presence of P. macularis chasmothecia. Furthermore, these insights provide a baseline for the validation of weather-driven models describing maturation and release of P. macularis ascospores, models that can eventually be incorporated into hop disease management programs.

Background The green peach aphid Myzus persicae is a major pest of many crops around the world, causing direct damage and acting as a vector for several viruses. This species has developed resistance to several insecticides, resulting in a greater emphasis on nonchemical methods of control. The aphidophagous ladybird, Harmonia conformis, is one of several species to predate on this pest. H. conformis is native to Australia, but has been exported to New Zealand, the USA and Europe as a biological control agent for horticultural pests and has now become established in several regions. Despite these introductions, the ability of H. conformis to predate on M. persicae has not yet been quantified. To address this knowledge gap, we measured the potential success of this natural enemy and its functional response over a range of temperatures. Results H. conformis displayed a Type II response over all temperatures assessed. The peak temperature for voracity was 32 °C, with a potential maximum daily predation rate of 204 aphids. Consumption of aphids by H. conformis on canola plants within a glasshouse was less than predicted from the laboratory-generated models. However, consumption increased significantly with increasing density of M. persicae. Conclusion H. conformis can contribute markedly to aphid suppression and could be incorporated into integrated pest management systems which rely on natural enemies, particularly during spring when temperatures increase above 25 °C. Furthermore, it would also be an ideal candidate for augmentative releases.

Weather parameters play an important role in the spread of potato late blight of caused by Phytophthora infestans (Mont.) de Bary has historically been serious disease of potatoes through worldwide, including India. Due to spatial variation in prevailing weather conditions, its severity varies from region to region. Disease development process and the weather parameters are well understood and have been utilized for disease developing forecasting models and decision support system. Therefore, an experiment was conducted for two consecutive cropping seasons (2017 & 2018) to develop a forecasting model against late blight of potato using stepwise regression analysis for Northern Himalayas in India. Maximum and minimum temperature, relative humidity, rainfall and wind speed appeared to be most significant factors in the potato late blight disease development. The meteorological conditions conducive for the development of potato late blight disease were characterized. Maximum and minimum temperatures in the range of 15.0 – 28.0°C and 2.0 – 12.0°C were found favorable for potato blight disease. Similarly, relative humidity, rainfall and wind speed in the range of 85 - 95 per cent, 15.5 - 20.75 mm and 1.0 - 5.5 Km h-1, respectively, were conducive for potato late blight disease which are helpful in disease development.

This paper offers a discussion of the rationale for the creation of sports categorization criteria based on sporting genealogy and the gendered body, as proposed by Torres et al. in their article ‘...

Intertrochanteric femur fracture nonunions are a rare complication that can be difficult to treat with limited evidence regarding treatment options. Revision fixation is typically reserved for well-aligned nonunions with sufficient femoral head bone stock. The most common implant used for revision fixation is a sliding hip screw implant. The use of a short cephalomedullary nail (CMN) for revision fixation has not been previously reported. This article presents a technique for reamed short CMN revision fixation of well-aligned nonunions with sufficient bone stock that is a simpler and potentially less morbid treatment option compared to open procedures with fixed-angle devices. For nonunions with poor femoral head bone stock and/or malaligned fractures, a fixed-angle implant, with or without a valgus osteotomy, may be necessary, while arthroplasty is reserved for nonunions with poor proximal femur bone stock that are not amenable to fixed-angle implant fixation.

The flaviviruses (family Flaviviridae) are a group of positive-strand RNA viruses, many of which pose serious risks to human health on a global scale. Here, we calibrate the timeline of flavivirus evolution using flavivirus-derived DNA sequences identified in animal genomes. We demonstrate that the family is at least 100 million years old and show that this timing can be integrated with dates inferred from co-phylogenetic analysis and paleontological records to produce a cohesive overview of flavivirus evolution in which the main subgroups originate early in animal evolution and broadly co-diverge with animal phyla. In addition, we show that the arthropod-borne ‘classical’ flaviviruses first evolved from tick-specific viruses, and only later adapted to become insect-borne. Our findings demonstrate that the biological properties of flaviviruses have been acquired over many millions of years of evolution, implying that broad-scale comparative analysis can reveal fundamental insights into flavivirus biology. We implement a novel approach to computational genomic studies of viruses that can support these efforts by enabling more efficient utilization of evolution-related domain knowledge in virus research. Significance Understanding how pathogenic viruses evolved can provide vital insights into their biology. In this study we use genomic data to show that flaviviruses – a group of viruses that includes important pathogens such as Dengue virus and hepatitis C virus - arose through an extended history of evolutionary interaction with host and vector species. Our findings show that comparative studies can productively utilise genomic data to reveal insights into flavivirus biology, which will help to facilitate the development of more effective antiviral treatments and strategies.

In addition to smoking and UV exposure, lifestyle factors, such as diet, nutrition, and physical activity, have been shown to play a significant role for many cancers. It is estimated that up to 50% of some cancer types are preventable; many through lifestyle and dietary changes with the presence or absence of certain dietary components strongly associated with an increased or decreased risk. Here we summarize the work that has been performed with polyphenols, with a focus on those derived from black raspberries. These have been extensively studied for the prevention and treatment of a variety of conditions and diseases. Here we focus on their use for the prevention or treatment of specific cancer types and the impact they have on biological systems. The aim is to highlight the need to improve our understanding of how the environment impacts upon the normal biological processes that affect health and disease, thereby, enabling us to implement smarter prevention and treatment measures.

Aedes aegypti (Linnaeus) was once highly prevalent across eastern Australia, resulting in epidemics of dengue fever. Drought conditions have led to a rapid rise in semi-permanent, urban water storage containers called rainwater tanks known to be critical larval habitat for the species. The presence of these larval habitats has increased the risk of establishment of highly urbanised, invasive mosquito vectors such as Ae. aegypti. Here we use a spatially explicit network model to examine the role that unsealed rainwater tanks may play in population connectivity of an Ae. aegypti invasion in suburbs of Brisbane, a major Australian city. We characterise movement between rainwater tanks as a diffusion-like process, limited by a maximum distance of movement, average life expectancy, and a probability that Ae. aegypti will cross wide open spaces such as roads. The simulation model was run against a number of scenarios that examined population spread through the rainwater tank network based on non-compliance rates of tanks (unsealed or sealed) and road grids. We show that Ae. aegypti tank infestation and population spread was greatest in areas of high tank density and road lengths were shortest e.g. cul-de-sacs. Rainwater tank non-compliance rates of over 30% show increased connectivity when compared to less than 10%, suggesting rainwater tanks non-compliance should be maintained under this level to minimize the spread of an invading Ae. aegypti population. These results presented as risk maps of Ae. aegypti spread across Brisbane, can assist health and government authorities on where to optimally target rainwater tank surveillance and educational activities. Supplementary Information The online version contains supplementary material available at 10.1007/s10530-021-02619-z.

BackgroundSeveral SARS-CoV-2 vaccines have shown clinical efficacy against Covid-19 infection but there remains uncertainty about the immune responses elicited by different regimens. This is a particularly important question for older people who are at increased clinical risk following infection and in whom immune senescence may limit vaccine responses. The BNT162b2 mRNA and ChAdOx1 adenovirus vaccines were the first two vaccines deployed in the UK programme using an 8–12 week ‘extended interval’.ObjectivesWe undertook analysis of the spike-specific antibody and cellular immune response in 131 participants aged 80+ years after the second dose of ‘extended interval’ dual vaccination with either BNT162b2 mRNA (n = 54) or ChAdOx1 (n = 77) adenovirus vaccine. Blood samples were taken 2–3 weeks after second vaccine and were paired with samples taken at 5-weeks after first vaccine which have been reported previously. Antibody responses were measured using the Elecsys® electrochemiluminescence immunoassay assay and cellular responses were assessed by IFN-γ ELISpot.ResultsAntibody responses against spike protein became detectable in all donors following dual vaccination with either vaccine. 4 donors had evidence of previous natural infection which is known to boost vaccine responses. Within the 53 infection-naïve donors the median antibody titre was 4030 U/ml (IQR 1892–8530) following BNT162b2 dual vaccination and 1405 (IQR 469.5–2543) in the 74 patients after the ChAdOx1 vaccine (p = p = 0.022).ConclusionDual vaccination with BNT162b2 or ChAdOx1 induces strong humoral immunity in older people following an extended interval protocol. Antibody responses are 2.9-times higher following the mRNA regimen whilst cellular responses are 1.4-times higher with the adenovirus-based vaccine. Differential patterns of immunogenicity are therefore elicited from the two vaccine platforms. It will be of interest to assess the relative stability of immune responses after these homologous vaccine regimens in order to assess the potential need for vaccine boosting. Furthermore, these findings indicate that heterologous vaccine platforms may offer the opportunity to further optimize vaccine responses.

The federal Cannabis Act came into force on Oct. 17, 2018, in Canada, making Canada only the second country in the world to legalize the cultivation, acquisition, possession and consumption of cannabis and its by-products. This provided a unique opportunity to evaluate the impact of this legislation on drug-related trauma.We performed a prospective observational study on the use of cannabis and other illicit drugs in the trauma population at a lead Canadian trauma centre in London, Ontario, in the 3 months before (July 1 to Sept. 30, 2018) and 3 months after (Nov. 1, 2018, to Jan. 31, 2019) the legalization of cannabis in Canada. We defined cannabis use as a positive cannabinoid screen result at the time of assessment by the trauma team. We also screened for opioids, amphetamines and cocaine.A total of 210 patients were assessed by our trauma service between July 1 and Sept. 30, 2018, and 141 patients were assessed between Nov. 1, 2018, and Jan. 31, 2019. Motor vehicle collisions were the most common cause of trauma both before (101 [48.1%]) and after (67 [47.5%]) legalization. The mean Injury Severity Score was 17.6 (standard deviation [SD] 13.0) and 19.7 (SD 14.8), respectively. Drug screens were done in 88 patients (41.9%) assessed before legalization and 99 patients (70.2%) assessed after legalization. There was no difference in the rate of positive cannabinoid screen results before and after legalization (22 [25%] v. 22 [22%]). There was a trend toward higher rates of positive cannabinoid screen results (2/10 [20%] v. 5/8 [62%]) and positive toxicology screen results (5/10 [50%] v. 6/8 [75%]) after legalization among patients with penetrating trauma, but our sample was too small to achieve statistical significance.We found no difference in the rates of positive cannabinoid screen results among patients assessed at our trauma centre in the 3 months before and the 3 months after legalization of cannabis; however, there was a trend toward an increase in the rates of positive results of toxicology screens and cannabinoid screens among those with penetrating trauma. These preliminary single-centre data showing no increased rates of cannabis use in patients with trauma after legalization are reassuring.La Loi fédérale sur le cannabis est entrée en vigueur ici le 17 octobre 2018, faisant du Canada le second pays à légaliser la culture, l’acquisition, la possession et la consommation du cannabis et de ses produits dérivés. Cette situation fournit une occasion unique d’évaluer l’impact de cette loi sur les traumatismes liés aux drogues.Nous avons procédé à une étude d’observation prospective sur la consommation du cannabis et d’autres drogues illicites chez une population de victimes de traumatismes dans un grand centre canadien de traumatologie de London, en Ontario, au cours des 3 mois précédant (1er juillet au 30 septembre 2018) et des 3 mois suivant (1er novembre 2018 au 31 janvier 2019) la légalisation du cannabis au Canada. La consommation de cannabis était confirmée par l’obtention de résultats positifs aux tests de dépistage des cannabinoïdes demandés par l’équipe de traumatologie. Nous avons aussi effectué un dépistage des opioïdes, des amphétamines et de la cocaïne.En tout, notre service de traumatologie a vu 210 patients entre le 1er juillet et le 30 septembre 2018, et 141 entre le 1er novembre 2018 et le 31 janvier 2019. Les accidents de la route ont été la plus fréquente cause de traumatisme avant (101 [48,1 %]) et après (67 [47,5 %]) la légalisation. L’indice moyen de gravité des blessures a été de 17,6 (écart-type [É.-T.] 13,0) et 19,7 (É.-T. 14,8), respectivement. Un dépistage de drogues a été effectué chez 88 patients (41,9 %) vus avant la légalisation et chez 99 patients (70,2 %) vus après la légalisation. On n’a observé aucune différence quant aux taux de résultats positifs aux tests de dépistage des cannabinoïdes enregistrés avant et après la légalisation (22 [25 %] c. 22 [22 %]). Les taux de résultats positifs aux tests de dépistage des cannabinoïdes (2/10 [20 %] c. 5/8 [62 %]) et aux tests toxicologiques (5/10 [50 %] c. 6/8 [75 %]) ont eu tendance à être plus élevés après la légalisation chez les patients victimes de traumatismes pénétrants, mais notre échantillon était trop petit pour atteindre une portée statistique.Nous n’avons observé aucune différence quant aux taux de résultats positifs au dépistage des cannabinoïdes au cours des 3 mois précédant et suivant la légalisation du cannabis; par contre, les taux de résultats positifs aux tests de dépistage des drogues et du cannabis ont eu tendance à être plus élevés chez les victimes de traumatismes pénétrants. Ces données préliminaires provenant d’un seul centre qui ne montrent pas d’augmentation des taux de consommation de cannabis chez les polytraumatisés sont rassurantes.

Background: In several countries, extended interval COVID-19 vaccination regimens are now used to accelerate population coverage, but the relative immunogenicity of different vaccines in older people remains uncertain. In this study we aimed to assess the antibody and cellular responses of older people after a single dose of either the BNT162b2 vaccine (tozinameran; Pfizer-BioNTech) or ChAdOx1 nCoV-19 vaccine (Oxford University-AstraZeneca). Methods: Participants aged 80 years or older, who did not live in a residential or care home or require assisted living, and had received a single dose of either the BNT162b2 vaccine or ChAdOx1 nCoV-19 vaccine were eligible to participate. Participants were recruited through local primary care networks in the West Midlands, UK. Blood samples and dried blood spots were taken 5-6 weeks after vaccination to assess adaptive immune responses using Elecsys electrochemiluminescence immunoassay and cellular responses by ELISpot. Primary endpoints were percentage response and quantification of adaptive immunity. Findings: Between Dec 29, 2020, and Feb 28, 2021, 165 participants were recruited and included in the analysis. 76 participants had received BNT162b2 (median age 84 years, IQR 82-89; range 80-98) and 89 had received ChAdOx1 nCoV-19 (median age 84 years, 81-87; 80-99). Antibody responses against the spike protein were detectable in 69 (93%) of 74 BNT162b2 vaccine recipients and 77 (87%) of 89 ChAdOx1 nCoV-19 vaccine recipients. Median antibody titres were of 19·3 U/mL (7·4-79·4) in the BNT162b2 vaccine recipients and 19·6 U/mL (6·1-60·0) in the ChAdOx1 nCoV-19 vaccine recipients (p=0·41). Spike protein-specific T-cell responses were observed in nine (12%) of 73 BNT162b2 vaccine recipients and 27 (31%) of 88 ChAdOx1 nCoV-19 vaccine recipients, and median responses were three-times higher in ChAdOx1 nCoV-19 vaccine recipients (24 spots per 1 × 106 peripheral blood mononuclear cells) than BNT162b2 vaccine recipients (eight spots per 1 × 106 peripheral blood mononuclear cells; p

Dr. Miller Edwin Preston was a surgeon with a deep interest in trauma and orthopaedics who practiced in Denver in the early 1900s. Dr. Preston arrived in Denver shortly after the creation of Denver's first city hospital in 1860. This hospital would later be renamed to Denver General Hospital and then Denver Health Medical Center. It excels for the quality of its emergency medicine residency program, a very high survival rate for severely injured patients and the clinical pathways and algorithms pertinent to the management of haemodynamically unstable pelvic ring injuries among others. Today, Dr. Preston's legacy of excellence in the management of trauma patients is alive and well at Denver Health Medical Center, the city's only level-one safety net hospital and academic affiliate of the University of Colorado Medical School.

BACKGROUND: Primary cytomegalovirus (CMV) infection during pregnancy carries a risk of congenital infection and possible severe sequelae. There is no established intervention for preventing congenital CMV infection. METHODS: In this multicenter, double-blind trial, pregnant women with primary CMV infection diagnosed before 24 weeks’ gestation were randomly assigned to receive a monthly infusion of CMV hyperimmune globulin (at a dose of 100 mg per kilogram of body weight) or matching placebo until delivery. The primary outcome was a composite of congenital CMV infection or fetal or neonatal death if CMV testing of the fetus or neonate was not performed. RESULTS: From 2012 to 2018, a total of 206,082 pregnant women were screened for primary CMV infection before 23 weeks of gestation; of the 712 participants (0.35%) who tested positive, 399 (56%) underwent randomization. The trial was stopped early for futility. Data on the primary outcome were available for 394 participants; a primary outcome event occurred in the fetus or neonate of 46 of 203 women (22.7%) in the group that received hyperimmune globulin and of 37 of 191 women (19.4%) in the placebo group (relative risk, 1.17; 95% confidence interval [CI], 0.80 to 1.72; P = 0.42). Death occurred in 4.9% of fetuses or neonates in the hyperimmune globulin group and in 2.6% in the placebo group (relative risk, 1.88; 95% CI, 0.66 to 5.41), preterm birth occurred in 12.2% and 8.3%, respectively (relative risk, 1.47; 95% CI, 0.81 to 2.67), and birth weight below the 5th percentile occurred in 10.3% and 5.4% (relative risk, 1.92; 95% CI, 0.92 to 3.99). One participant in the hyperimmune globulin group had a severe allergic reaction to the first infusion. Participants who received hyperimmune globulin had a higher incidence of headaches and shaking chills while receiving infusions than participants who received placebo. CONCLUSIONS: Among pregnant women, administration of CMV hyperimmune globulin starting before 24 weeks’ gestation did not result in a lower incidence of a composite of congenital CMV infection or perinatal death than placebo. (Funded by the Eunice Kennedy Shriver National Institute of Child Health and Human Development and the National Center for Advancing Translational Sciences; ClinicalTrials.gov number, NCT01376778.)

ObjectiveA systematic review, meta-analysis and meta-regression were performed on selected studies to investigate the incidence of atrial fibrillation (AF) among athletes compared with non-athlete controls.DesignMeta-analysis with heterogeneity analysis and subsequent meta-regression to model covariates were performed. The mode of exercise (endurance and mixed sports) and age were the a priori determined covariates.Data sourcesPubMed, MEDLINE, Science Direct, SPORTDiscus and the Cochrane library were searched.Eligibility criteriaResearch articles published after 1990 and before 2 December 2020 were included if they reported the number of AF cases in athletes with non-athlete (physically active or inactive) control groups, were case–control or cohort studies and if data allowed calculation of OR.ResultsThe risk of developing AF was significantly higher in athletes than in non-athlete controls (OR: 2.46; 95% CI 1.73 to 3.51; pConclusionAthletes have a significantly greater likelihood of developing AF compared with non-athlete controls, with those participating in mixed sport and younger athletes at the greatest risk. Future studies of AF prevalence in athletes according to specific exercise dose parameters, including training and competition history, may aid further in delineating those at risk.

Mosquito vectors transmit various diseases through blood feeding, required for their egg development. Hence, blood feeding is a major physiological event in their life cycle, during which hundreds of genes are tightly regulated. Blood is a rich source of proteins for mosquitoes, but also contains many other molecules including microRNAs (miRNAs). Here, we found that human blood miRNAs are transported abundantly into the fat body tissue of Aedes aegypti, a key metabolic center in post-blood feeding reproductive events, where they target and regulate mosquito genes. Using an artificial diet spiked with the mimic of an abundant and stable human blood miRNA, hsa-miR-21-5p, and proteomics analysis, we found over 40 proteins showing differential expression in female Ae. aegypti mosquitoes after feeding. Of interest, we found that the miRNA positively regulates the vitellogenin gene, coding for a yolk protein produced in the mosquito fat body and then transported to the ovaries as a protein source for egg production. Inhibition of hsa-miR-21-5p followed by human blood feeding led to a statistically insignificant reduction in progeny production. The results provide another example of the involvement of small regulatory molecules in the interaction of taxonomically vastly different taxa., Perdomo et al. fed mosquitos (Aedes aegypti) a diet spiked with human blood miRNA, hsa-miR-21-5p and used proteomics analysis to show differential protein expression in female Ae. aegypti mosquitoes after feeding. They showed that hsa-miR-21-5p positively regulated vitellogenin, which plays a role in egg production, thus could have effects on Ae. aegypti progeny production.

The physiological demands of pregnancy inevitably result in alterations in both biochemical and hematological parameters as fetal development occurs. The shifts observed in successful pregnancy in bottlenose dolphins Tursiops truncatus to support both fetal physiological needs and maternal basal requirements have been established according to each trimester. Detecting aberrations in blood-based biomarkers could help facilitate diagnosis of gestational abnormalities, improve our understanding of factors influencing reproductive outcomes and aid in prediction of reproductive failure. This study retrospectively analyzed 263 blood samples from 15 bottlenose dolphins in 21 failed pregnancies over 28 yr (1989-2017). Most samples remained within normal pregnancy reference ranges; however, significant shifts were observed between trimesters. Hematological alterations, compared to successful pregnancy reference ranges from previously published data, were consistent across failed pregnancies and included an increased prevalence of elevated 2nd and 3rd trimester neutrophils, elevated 2nd trimester monocytes and decreased 3rd trimester eosinophils. In addition, low hematocrit and low red blood cells were more prevalent in the 2nd trimester. Biochemical shifts included an increased prevalence of elevated creatine phosphokinase in the 3rd trimester outside of the normal reference ranges. Across failed pregnancies, calcium and iron were decreased in the 3rd trimester. Significantly decreased progesterone in the 3rd trimester was a negative prognostic indicator of pregnancy outcome with decreasing 3rd trimester progesterone associated with failed pregnancy. This study demonstrates the use of blood-based biomarkers as possible predictors of pregnancy outcome in bottlenose dolphins.

Mass mortalities in flying-foxes occur in summers that reach extremely hot temperatures. In this study, we examine the spatiotemporal distributions of mortality from pup abandonments and extreme heat events in Australian flying-fox camps during the 2019–20 summer. We recorded data on flying-fox mortality in known affected camps and applied a standard method to estimate the number of deaths. Pup mortalities from abandonments were recorded in 10 camps in New South Wales. A minimum estimate of 2612 flying-foxes died in pup abandonments, the majority of which occurred in one camp in Bomaderry. Die-offs from extreme heat events were recorded in 40 camps associated with eight separate heat events in south-eastern Australia. A minimum estimate of 72 175 flying-foxes died during these heat events, which all occurred within the range of the threatened grey-headed flying-fox (Pteropus poliocephalus). Further, 409 and 2251 live flying-foxes were taken into care from pup abandonments and heat events respectively. The minimum mortality estimated represents the highest recorded mortality of Australian flying-foxes within a single summer. This highlights a need to restore vegetation in flying-fox foraging areas and camps, address anthropogenic climate change and gather more empirical data to inform heat stress interventions to minimise flying-fox mortalities.

Substance use is a recognized risk factor for HIV acquisition, transmission and progression in South Africa. Persons who use drugs (PWUD) and access specialist substance abuse treatment centers (SSATCs) are a potentially critical target group for HIV services because of the severity of their substance use and associated health risks. SSATCs represent an opportunity for integrated programming, particularly HIV testing services (HTS), to reach PWUD who are at an increased risk of or living with HIV. This analysis of national SSATC admission data explores self-reported HIV testing and associated factors to identify coverage gaps and integration opportunities. The South African Community Epidemiology Network on Drug Use (SACENDU) collects routine surveillance data to monitor national treatment admission trends in alcohol and other drug use. SACENDU data from 2012 to 2017 was analyzed using chi-square test of independence and logistic regression to examine associations between HTS, demographic characteristics and substances of use. Of 87,339 treatment admissions, 47.5% (n = 41,481) of patients had not accessed HTS in the prior 12 months. HTS was reported less frequently by patients whose primary substance of use was cannabis or those with polysubstance use (36.9% and 41.1%, respectively). None of the substance use sub-groups reported a testing rate above 70%. Compared to specific reference groups, logistic regression showed those with lower odds of HTS were: 15–19 years (OR = 0.59); had primary-level education (OR = 0.51); were scholars/learners (OR = 0.27); and primarily cannabis users (OR = 0.64). Patients whose primary drug was heroin had higher odds of testing (OR = 2.45) as did those who injected drugs (OR = 2.86). Given the low coverage and decreased odds of self-reported HTS among sub-groups of patients in SSATCs, the integration of HIV services for PWUD should be a priority in South Africa and a focus of the national HIV strategy.

Photosynthetic inefficiencies limit the productivity and sustainability of crop production and the resilience of agriculture to future societal and environmental challenges. Rubisco is a key target for improvement as it plays a central role in carbon fixation during photosynthesis and is remarkably inefficient. Introduction of mutations to the chloroplast-encoded Rubisco large subunit rbcL is of particular interest for improving the catalytic activity and efficiency of the enzyme. However, manipulation of rbcL is hampered by its location in the plastome, with many species recalcitrant to plastome transformation, and by the plastid's efficient repair system, which can prevent effective maintenance of mutations introduced with homologous recombination. Here we present a system where the introduction of a number of silent mutations into rbcL within the model plant Nicotiana tabacum facilitates simplified screening via additional restriction enzyme sites. This system was used to successfully generate a range of transplastomic lines from wild-type N. tabacum with stable point mutations within rbcL in 40% of the transformants, allowing assessment of the effect of these mutations on Rubisco assembly and activity. With further optimization the approach offers a viable way forward for mutagenic testing of Rubisco function in planta within tobacco and modification of rbcL in other crops where chloroplast transformation is feasible. The transformation strategy could also be applied to introduce point mutations in other chloroplast-encoded genes.

Sperm whalesPhyseter macrocephalusand long-finned pilot whalesGlobicephala melasare the most abundant species among the community of deep-diving cetaceans occurring off the west coast of Ireland, northeast Atlantic. To address a knowledge gap on these elusive species in an area subject to increasing levels of anthropogenic noise, fixed bottom-mounted autonomous acoustic recorders were deployed from 2014 to 2016 at 13 locations. Acoustic data were collected over 2410 cumulative days, for a total of 9179 h of recordings, with sperm whale clicks and pilot whale whistles detected on 79 and 53% of the days monitored, respectively. Diel, lunar and seasonal effects on the acoustic occurrence of sperm whales and long-finned pilot whales were investigated for individual recording sites and for each recording year using generalised estimating equations. Large differences in acoustic occurrence across stations for both species highlighted the existence of more critical locations throughout the year, especially to the north of the shelf edge. Temporally, significant modulations were found for both species at all scales investigated, but the lack of consistency across the study area emphasises the need to exercise great caution when inferring general tendencies based on local patterns. The variability of spatio-temporal patterns indicates a flexibility in the distribution of sperm whales and long-finned pilot whales off the west coast of Ireland, highlighting the challenge in establishing management and mitigation measures and stressing the need of long-term, year-round monitoring.

Diabetes mellitus causes a progressive loss of functional efficacy in stem cells, including cardiac progenitor cells (CPCs). The underlying molecular mechanism is still not known. MicroRNAs (miRNAs) are small, non-coding RNA molecules that regulate genes at the post-transcriptional level. We aimed to determine if diabetes mellitus induces dysregulation of miRNAs in CPCs and to test if in vitro therapeutic modulation of miRNAs would improve the functions of diabetic CPCs. CPCs were isolated from a mouse model of type 2 diabetes (db/db), non-diabetic mice and human right atrial appendage heart tissue. Total RNA isolated from mouse CPCs was miRNA profiled using Nanostring analysis. Bioinformatic analysis was employed to predict the functional effects of altered miRNAs. MS analysis was applied to determine the targets, which were confirmed by western blot analysis. Finally, to assess the beneficial effects of therapeutic modulation of miRNAs in vitro and in vivo, prosurvival miR-30c-5p was overexpressed in mouse and human diabetic CPCs, and the functional consequences were determined by measuring the level of apoptotic cell death, cardiac function and mitochondrial membrane potential (MMP). Among 599 miRNAs analysed in mouse CPCs via Nanostring analysis, 16 miRNAs showed significant dysregulation in the diabetic CPCs. Using bioinformatics tools and quantitative real-time PCR (qPCR) validation, four altered miRNAs (miR-30c-5p, miR-329-3p, miR-376c-3p and miR-495-3p) were identified to play an important role in cell proliferation and survival. Diabetes mellitus significantly downregulated miR-30c-5p, while it upregulated miR-329-3p, miR-376c-3p and miR-495-3p. MS analysis revealed proapoptotic voltage-dependent anion-selective channel 1 (VDAC1) as a direct target for miR-30c-5p, and cell cycle regulator, cyclin-dependent protein kinase 6 (CDK6), as the direct target for miR-329-3p, miR-376c-3p and miR-495-3p. Western blot analyses showed a marked increase in VDAC1 expression, while CDK6 expression was downregulated in diabetic CPCs. Finally, in vitro and in vivo overexpression of miR-30c-5p markedly reduced the apoptotic cell death and preserved MMP in diabetic CPCs via inhibition of VDAC1. Our results demonstrate that diabetes mellitus induces a marked dysregulation of miRNAs associated with stem cell survival, proliferation and differentiation, and that therapeutic overexpression of prosurvival miR-30c-5p reduced diabetes-induced cell death and loss of MMP in CPCs via the newly identified target for miR-30c-5p, VDAC1.

Senescence is a state of stable proliferative arrest, generally accompanied by the senescence-associated secretory phenotype, which modulates tissue homeostasis. Enhancer-promoter interactions, facilitated by chromatin loops, play a key role in gene regulation but their relevance in senescence remains elusive. Here, we use Hi-C to show that oncogenic RAS-induced senescence in human diploid fibroblasts is accompanied by extensive enhancer-promoter rewiring, which is closely connected with dynamic cohesin binding to the genome. We find de novo cohesin peaks often at the 3′ end of a subset of active genes. RAS-induced de novo cohesin peaks are transcription-dependent and enriched for senescence-associated genes, exemplified by IL1B, where de novo cohesin binding is involved in new loop formation. Similar IL1B induction with de novo cohesin appearance and new loop formation are observed in terminally differentiated macrophages, but not TNFα-treated cells. These results suggest that RAS-induced senescence represents a cell fate determination-like process characterised by a unique gene expression profile and 3D genome folding signature, mediated in part through cohesin redistribution on chromatin., Senescence is a state of stable proliferative arrest. Here, the authors perform Hi-C analysis on oncogenic RAS-induced senescence in human fibroblasts and characterize the changes in the 3D genome folding associated with the senescence-specific gene expression profile, which are mediated in part through cohesin redistribution on chromatin.

Supplemental Digital Content is available in the text., We examined data from 374 laboratories staining for Ki-67 as part of external quality assessment over 8 runs between 2013 and 2017 (total data sets=2601). One of 5 primary antibodies was used for 94.8% of submissions, with MIB-1 (Agilent Dako) comprising 58.8% of the total. Examining assessment score as a continuous variable showed the 30-9 (Ventana) and K2 (Leica Biosystems) clones were associated with the highest mean scores (17.0; 95% confidence interval, 16.8-17.2 and 16.3; 95% confidence interval, 15.9-16.6, respectively). Stain quality was not significantly different between them. Both were associated with significantly better staining compared with MIB-1 (Agilent Dako), MM1 (Leica Biosystems), and SP6 from various suppliers (P

Insect-specific flaviviruses (ISFs) circulate in nature due to vertical transmission in mosquitoes and do not infect vertebrates. ISFs include two distinct lineages – classical ISFs (cISFs) that evolved independently and dual host associated ISFs (dISFs) that are proposed to diverge from mosquito-borne flaviviruses (MBFs). Compared to pathogenic flaviviruses, ISFs are relatively poorly studied, and their molecular biology remains largely unexplored. In this study we focused on the characterisation of ISF 3’UTRs and their ability to produce subgenomic flaviviral RNAs – noncoding viral RNAs that are known as important determinants of transmission and replication of pathogenetic flaviviruses. We demonstrated that cISFs and dISFs produce sfRNAs by employing a highly conserved mechanism of resistance to degradation by the cellular 5’-3’ exoribonuclease XRN1. We determined the secondary structures of complete 3’UTRs and experimentally identified structured RNA elements that resist degradation by XRN1 (xrRNAs) in divergent representatives of cISF and dISF clades. We discovered a novel class of xrRNAs in dISFs and identified structurally divergent xrRNA in Anopheles-associated cISFs. Phylogenetic analyses based on sequences and secondary structures of xrRNAs and complete 3’UTRs reveal that xrRNAs of cISFs and MBFs/dISFs evolved from a common xrRNA ancestor similar to the xrRNA of Anopheles-associated cISFs. Additionally, we found that duplications of xrRNAs occurred independently in ISF and MBF clades. Using ISF mutants deficient in the production of sfRNAs, we found that individual sfRNAs of ISFs have redundant functions. We conclude that duplicated xrRNAs were selected in the evolution of flaviviruses to ensure that sfRNA is produced if one of the xrRNAs lose XRN1 resistance due to mutations or misfolding.

Funder: Biotechnology and Biological Sciences Research Council; FundRef: http://dx.doi.org/10.13039/501100000268, Funder: Milky Way Research Foundation, Ageing is the gradual decline in organismal fitness that occurs over time leading to tissue dysfunction and disease. At the cellular level, ageing is associated with reduced function, altered gene expression and a perturbed epigenome. Recent work has demonstrated that the epigenome is already rejuvenated by the maturation phase of somatic cell reprogramming, which suggests full reprogramming is not required to reverse ageing of somatic cells. Here we have developed the first "maturation phase transient reprogramming" (MPTR) method, where reprogramming factors are selectively expressed until this rejuvenation point then withdrawn. Applying MPTR to dermal fibroblasts from middle-aged donors, we found that cells temporarily lose and then reacquire their fibroblast identity, possibly as a result of epigenetic memory at enhancers and/or persistent expression of some fibroblast genes. Excitingly, our method substantially rejuvenated multiple cellular attributes including the transcriptome, which was rejuvenated by around 30 years as measured by a novel transcriptome clock. The epigenome was rejuvenated to a similar extent, including H3K9me3 levels and the DNA methylation ageing clock. The magnitude of rejuvenation instigated by MPTR appears substantially greater than that achieved in previous transient reprogramming protocols. In addition, MPTR fibroblasts produced youthful levels of collagen proteins, and showed partial functional rejuvenation of their migration speed. Finally, our work suggests that optimal time windows exist for rejuvenating the transcriptome and the epigenome. Overall, we demonstrate that it is possible to separate rejuvenation from complete pluripotency reprogramming, which should facilitate the discovery of novel anti-ageing genes and therapies.

The multinational Arabidopsis research community is highly collaborative and over the past thirty years these activities have been documented by the Multinational Arabidopsis Steering Committee (MASC). Here, we (a) highlight recent research advances made with the reference plantArabidopsis thaliana; (b) provide summaries from recent reports submitted by MASC subcommittees, projects and resources associated with MASC and from MASC country representatives; and (c) initiate a call for ideas and foci for the "fourth decadal roadmap," which will advise and coordinate the global activities of the Arabidopsis research community., UKRI-BBSRC grant [BB/M004376/1]; HHMI Faculty Scholar Fellowship; Scientific and Technological Research Council of TurkeyTurkiye Bilimsel ve Teknolojik Arastirma Kurumu (TUBITAK) [118Z137], UKRI-BBSRC grant, Grant/Award Number: BB/M004376/1; HHMI Faculty Scholar Fellowship; the Scientific and Technological Research Council of Turkey, Grant/Award Number: 118Z137

Using an experimental approach, we analyzed the self-reported changes in farmers’ attitudes toward the African lion (Panthera leo) and a community-based lion conservation program (i.e., the Long Shields Community Guardians), before and after implementation. This program protects livestock and mitigates lion depredation through non-lethal means, with the aim of promoting human-lion coexistence. Results indicated a significant positive shift in attitudes of lions by farmers in the treatment group. This was also the case for farmers in what was recognized as a second unplanned treatment group, called the intermediate group, who learned about the program through communication within their peer network. This article contributed to the growing literature on conservation evaluation and demonstrates that people’s attitudes are valuable for assessing the impact of conservation programs.

Context African production landscapes are diverse, with multiple cassava cultivars grown in small patches amongst a diversity of other crops. Studies on how diverse smallholder landscapes impact herbivore pest outbreak risk have not been carried out in sub-Saharan Africa. Objectives Bemisia tabaci is a cryptic pest species complex that cause damage to cassava through feeding and vectoring plant-virus diseases and are known to reach very high densities in certain contexts. However, the factors driving this phenomenon are unclear. Methods Bemisia density data in cassava across a large number of sites representing a geographic gradient across Uganda, Tanzania and Malawi were collected. We tested whether in-field or landscape factors associated with land-use patterns underpinned Bemisia density variability and parasitism. Results We found the B. tabaci SSA1 species dominated our study sites, although other species were also common in some cassava fields. Factors associated with the surrounding landscape were unimportant for explaining variability in adult density, but the in-field variables of cassava age and cultivar were very important. The density of nymphs and the parasitism of nymphs was heavily influenced by a diversity of landscape factors surrounding the field, including the size of focal cassava field, and area of cassava in the landscape. However, unlike the trend from many other studies on drivers of natural enemy populations, this pattern was not solely related to the amount of non-crop vegetation, or the diversity of crops grown in the landscape. Conclusions Our findings provide management options to reduce whitefly abundance, including describing the characteristics of landscapes with high parasitism. The choice of cassava cultivar by the farmer is critical to reduce whitefly outbreak risk at the landscape-scale.

Many cancers are termed immunoevasive due to expression of immunomodulatory ligands. Programmed death ligand-1 (PD-L1) and cluster of differentiation 80/86 (CD80/86) interact with their receptors, programmed death receptor-1 (PD-1) and cytotoxic T-lymphocyte antigen-4 (CTLA-4), respectively, on tumor-infiltrating leukocytes eliciting immunosuppression. Immunotherapies aimed at blocking these interactions are revolutionizing cancer treatments, albeit in an inadequately described patient subset. To address the issue of patient stratification for immune checkpoint intervention, we quantitatively imaged PD-1/PD-L1 interactions in tumor samples from patients, employing an assay that readily detects these intercellular protein–protein interactions in the less than or equal to 10 nm range. These analyses across multiple patient cohorts demonstrated the intercancer, interpatient, and intratumoral heterogeneity of interacting immune checkpoints. The PD-1/PD-L1 interaction was not correlated with clinical PD-L1 expression scores in malignant melanoma. Crucially, among anti-PD-1–treated patients with metastatic non–small cell lung cancer, those with lower PD-1/PD-L1 interaction had significantly worsened survival. It is surmised that within tumors selecting for an elevated level of PD-1/PD-L1 interaction, there is a greater dependence on this pathway for immune evasion and hence, they exhibit more impressive patient response to intervention. Significance: Quantitation of immune checkpoint interaction by direct imaging demonstrates that immunotherapy-treated patients with metastatic NSCLC with a low extent of PD-1/PD-L1 interaction show significantly worse outcome.

Accurate assessment of chemotherapy response provides the means to terminate ineffective treatment, trial alternative drug regimens or schedules and reduce dose to minimize toxicity. Here, we have compared circulating tumor DNA (ctDNA) with carcinoembryonic antigen (CEA) for the cycle by cycle assessment of chemotherapy response in 30 patients with metastatic colorectal cancer. CtDNA (quantified using individualized digital droplet PCR (ddPCR) assays) and CEA levels were determined immediately prior to each chemotherapy cycle over time periods ranging from 42–548 days (average of 10 time points/patient). Twenty-nine/thirty (97%) patients had detectable ctDNA compared with 83% whose tumors were CEA-positive (>5 ng/ml) during the monitoring course. Over the course of treatment, 20 disease progression events were detected by computed tomography; ctDNA predicted significantly more of these events than CEA (16 (80%) versus 6 (30%), respectively; P-value = 0.004). When progression was detected by both ctDNA and CEA, the rise in ctDNA occurred significantly earlier than CEA (P-value = 0.046). Partial responses to chemotherapy were also detected more frequently by ctDNA, although this was not significant (P-value = 0.07). In addition, another 28 colorectal cancer patients who underwent potentially curative surgery and showed no evidence of residual disease were monitored with ctDNA for up to 2 years. Clinical relapse was observed in 6/28 (21%) patients. Four out of 6 of these patients showed a significant increase in ctDNA at or prior to relapse. Overall, ctDNA analyses were able to be performed in a clinically relevant timeline and were a more sensitive and responsive measure of tumor burden than CEA.

International audience; Untangling chromatin interactions The plant nucleus contains myriad subdomains that define and are defined by the composition of their chromatin. On a whole nucleus scale, this includes regions of active euchromatin and inactive heterochromatin, although the boundaries between these states are blurred. Different loci constantly enter and exit nuclear structures including the nucleolus and transient regulatory nuclear bodies. Chromatin is defined by its complex combinations of epigenetic modifications and variation in its constituent histone proteins. Here we preview articles that describe many of the mechanisms that regulate this dynamic chromatin.