Resolution doubling in light-sheet microscopy via oblique plane structured illumination.

Structured illumination microscopy (SIM) doubles the spatial resolution of a fluorescence microscope without requiring high laser powers or specialized fluorophores. However, the excitation of out-of-focus fluorescence can accelerate photobleaching and phototoxicity. In contrast, light-sheet fluorescence microscopy (LSFM) largely avoids exciting out-of-focus fluorescence, thereby enabling volumetric imaging with low photobleaching and intrinsic optical sectioning. Combining SIM with LSFM would enable gentle three-dimensional (3D) imaging at doubled resolution. However, multiple orientations of the illumination pattern, which are needed for isotropic resolution doubling in SIM, are challenging to implement in a light-sheet format. Here we show that multidirectional structured illumination can be implemented in oblique plane microscopy, an LSFM technique that uses a single objective for excitation and detection, in a straightforward manner. We demonstrate isotropic lateral resolution below 150 nm, combined with lower phototoxicity compared to traditional SIM systems and volumetric acquisition speed exceeding 1 Hz.

A Burkholderia cenocepacia-like environmental isolate strongly inhibits the plant fungal pathogen Zymoseptoria tritici.

Fungal phytopathogens cause significant reductions in agricultural yields annually, and overusing chemical fungicides for their control leads to environmental pollution and the emergence of resistant pathogens. Exploring natural isolates with strong antagonistic effects against pathogens can improve our understanding of their ecology and develop new treatments for the future. We isolated and characterized a novel bacterial strain associated with the species Burkholderia cenocepacia, termed APO9, which strongly inhibits Zymoseptoria tritici, a commercially important pathogenic fungus causing Septoria tritici blotch in wheat. Additionally, this strain exhibits inhibitory activity against four other phytopathogens. We found that physical contact plays a crucial role for APO9's antagonistic capacity. Genome sequencing of APO9 and biosynthetic gene cluster (BGC) analysis identified nine classes of BGCs and three types of secretion systems (types II, III, and IV), which may be involved in the inhibition of Z. tritici and other pathogens. To identify genes driving APO9's inhibitory activity, we screened a library containing 1,602 transposon mutants and identified five genes whose inactivation reduced inhibition efficiency. One such gene encodes for a diaminopimelate decarboxylase located in a terpenoid biosynthesis gene cluster. Phylogenetic analysis revealed that while some of these genes are also found across the Burkholderia genus, as well as in other Betaproteobacteria, the combination of these genes is unique to the Burkholderia cepacia complex. These findings suggest that the inhibitory capacity of APO9 is complex and not limited to a single mechanism, and may play a role in the interaction between various Burkholderia species and various phytopathogens within diverse plant ecosystems. IMPORTANCE: The detrimental effects of fungal pathogens on crop yields are substantial. The overuse of chemical fungicides contributes not only to environmental pollution but also to the emergence of resistant pathogens. Investigating natural isolates with strong antagonistic effects against pathogens can improve our understanding of their ecology and develop new treatments for the future. We discovered and examined a unique bacterial strain that demonstrates significant inhibitory activity against several phytopathogens. Our research demonstrates that this strain has a wide spectrum of inhibitory actions against plant pathogens, functioning through a complex mechanism. This plays a vital role in the interactions between plant microbiota and phytopathogens.

Mitochondria at the Nanoscale: Physics Meets Biology-What Does It Mean for Medicine?

Mitochondria are commonly perceived as "cellular power plants". Intriguingly, power conversion is not their only function. In the first part of this paper, we review the role of mitochondria in the evolution of eukaryotic organisms and in the regulation of the human body, specifically focusing on cancer and autism in relation to mitochondrial dysfunction. In the second part, we overview our previous works, revealing the physical principles of operation for proton-pumping complexes in the inner mitochondrial membrane. Our proposed simple models reveal the physical mechanisms of energy exchange. They can be further expanded to answer open questions about mitochondrial functions and the medical treatment of diseases associated with mitochondrial disorders.

Ketamine Efficacy for Management of Status Epilepticus: Considerations for Prehospital Clinicians.

Current first-line therapies for seizure management recommend benzodiazepines, which target gamma-aminobutyric acid type A channels to stop the seizure activity. However, seizures may be refractory to traditional first-line therapies, transitioning into status epilepticus and becoming resistant to gamma-aminobutyric acid type A augmenting drugs. Although there are other antiseizure medications available for clinicians to use in the intensive care unit, these options can be less readily available outside of the intensive care unit and entirely absent in the prehospital setting. Instead, patients frequently receive multiple doses of first-line agents with increased risk of hemodynamic or airway collapse. Ketamine is readily available in the prehospital setting and emergency department, has well-established antiseizure effects with a favorable safety profile, and is a drug often used for several other indications. This article aimed to explore the utilization of ketamine for seizure management in the prehospital setting, reviewing seizure pathophysiology, established treatment mechanisms of action and pharmacokinetics, and potential benefits of early ketamine use in status epilepticus.

Imaging of pediatric ovarian tumors: A COG Diagnostic Imaging Committee/SPR Oncology Committee White Paper.

Ovarian tumors in children are uncommon. Like those arising in the adult population, they may be broadly divided into germ cell, sex cord, and surface epithelium subtypes; however, germ cell tumors comprise the majority of lesions in children, whereas tumors of surface epithelial origin predominate in adults. Diagnostic workup, including the use of imaging, requires an approach that often differs from that required in an adult. This paper offers consensus recommendations for imaging of pediatric patients with a known or suspected primary ovarian malignancy at diagnosis and during follow-up.

Imaging of pediatric testicular tumors: A COG Diagnostic Imaging Committee/SPR Oncology Committee White Paper.

Primary intratesticular tumors are uncommon in children, but incidence and risk of malignancy both sharply increase during adolescence. Ultrasound is the mainstay for imaging the primary lesion, and cross-sectional modalities are often required for evaluation of regional or distant disease. However, variations to this approach are dictated by additional clinical and imaging nuances. This paper offers consensus recommendations for imaging of pediatric patients with a known or suspected primary testicular malignancy at diagnosis and during follow-up.

Increased drought severity tracks warming in the United States' largest river basin.

Across the Upper Missouri River Basin, the recent drought of 2000 to 2010, known as the "turn-of-the-century drought," was likely more severe than any in the instrumental record including the Dust Bowl drought. However, until now, adequate proxy records needed to better understand this event with regard to long-term variability have been lacking. Here we examine 1,200 y of streamflow from a network of 17 new tree-ring-based reconstructions for gages across the upper Missouri basin and an independent reconstruction of warm-season regional temperature in order to place the recent drought in a long-term climate context. We find that temperature has increasingly influenced the severity of drought events by decreasing runoff efficiency in the basin since the late 20th century (1980s) onward. The occurrence of extreme heat, higher evapotranspiration, and associated low-flow conditions across the basin has increased substantially over the 20th and 21st centuries, and recent warming aligns with increasing drought severities that rival or exceed any estimated over the last 12 centuries. Future warming is anticipated to cause increasingly severe droughts by enhancing water deficits that could prove challenging for water management.

Local groundwater decline exacerbates response of dryland riparian woodlands to climatic drought.

Dryland riparian woodlands are considered to be locally buffered from droughts by shallow and stable groundwater levels. However, climate change is causing more frequent and severe drought events, accompanied by warmer temperatures, collectively threatening the persistence of these groundwater dependent ecosystems through a combination of increasing evaporative demand and decreasing groundwater supply. We conducted a dendro-isotopic analysis of radial growth and seasonal (semi-annual) carbon isotope discrimination (Δ13 C) to investigate the response of riparian cottonwood stands to the unprecedented California-wide drought from 2012 to 2019, along the largest remaining free-flowing river in Southern California. Our goals were to identify principal drivers and indicators of drought stress for dryland riparian woodlands, determine their thresholds of tolerance to hydroclimatic stressors, and ultimately assess their vulnerability to climate change. Riparian trees were highly responsive to drought conditions along the river, exhibiting suppressed growth and strong stomatal closure (inferred from reduced Δ13 C) during peak drought years. However, patterns of radial growth and Δ13 C were quite variable among sites that differed in climatic conditions and rate of groundwater decline. We show that the rate of groundwater decline, as opposed to climate factors, was the primary driver of site differences in drought stress, and trees showed greater sensitivity to temperature at sites subjected to faster groundwater decline. Across sites, higher correlation between radial growth and Δ13 C for individual trees, and higher inter-correlation of Δ13 C among trees were indicative of greater drought stress. Trees showed a threshold of tolerance to groundwater decline at 0.5 m year-1 beyond which drought stress became increasingly evident and severe. For sites that exceeded this threshold, peak physiological stress occurred when total groundwater recession exceeded ~3 m. These findings indicate that drought-induced groundwater decline associated with more extreme droughts is a primary threat to dryland riparian woodlands and increases their susceptibility to projected warmer temperatures.

Positive interactions within and between populations decrease the likelihood of evolutionary rescue.

Positive interactions, including intraspecies cooperation and interspecies mutualisms, play crucial roles in shaping the structure and function of many ecosystems, ranging from plant communities to the human microbiome. While the evolutionary forces that form and maintain positive interactions have been investigated extensively, the influence of positive interactions on the ability of species to adapt to new environments is still poorly understood. Here, we use numerical simulations and theoretical analyses to study how positive interactions impact the likelihood that populations survive after an environment deteriorates, such that survival in the new environment requires quick adaptation via the rise of new mutants-a scenario known as evolutionary rescue. We find that the probability of evolutionary rescue in populations engaged in positive interactions is reduced significantly. In cooperating populations, this reduction is largely due to the fact that survival may require at least a minimal number of individuals, meaning that adapted mutants must arise and spread before the population declines below this threshold. In mutualistic populations, the rescue probability is decreased further due to two additional effects-the need for both mutualistic partners to adapt to the new environment, and competition between the two species. Finally, we show that the presence of cheaters reduces the likelihood of evolutionary rescue even further, making it extremely unlikely. These results indicate that while positive interactions may be beneficial in stable environments, they can hinder adaptation to changing environments and thereby elevate the risk of population collapse. Furthermore, these results may hint at the selective pressures that drove co-dependent unicellular species to form more adaptable organisms able to differentiate into multiple phenotypes, including multicellular life.

Response of riparian vegetation to short- and long-term hydrologic variation.

Increasing demand for river water now conflicts with an increasing desire to maintain riparian ecosystems. Efficiently managing river flows for riparian vegetation requires an understanding of the time scale of flow effects, but this information is limited by the absence of long-term studies of vegetation change in response to flow variation. To investigate the influence of short- and long-term flow variability and dam operation on riparian vegetation, we determined the occurrence of 107 plant species in 133 permanent plots of known inundating discharge along the Gunnison River in Colorado on five different occasions between 1990 and 2013. Individual species moved up and down the gradient of inundating discharge coincident with increases and decreases in mean annual flow, and the correlations between flow and species occurrence were strongest when flows were weighted by time before vegetation sampling with a median half-life of 1.5 years. Some tall, rhizomatous, perennial species, however, responded to flows on a longer time scale. Logistic regression of species occurrence showed a significant relation with inundation duration for 70 out of 107 species. Plot species richness and total vegetative cover decreased in association with desiccation at low inundation durations and with fluvial disturbance at high inundation durations. Within-plot similarity in species occurrence between years decreased strongly with increasing inundation duration. Moderate inundation durations were dominated by tall, rhizomatous, perennial herbs, including invasive Phalaris arundinacea (reed canary grass). Over the 23-year study period, species richness declined, and the proportion of rhizomatous perennials increased, consistent with the hypothesis that decreases in flow peaks and increases in low flows caused by flow regulation have decreased establishment opportunities for disturbance-dependent species. In summary, annual-scale changes in vegetation were strongly influenced by flow variation, and decadal-scale changes were influenced by decreases in fluvial disturbance from upstream flow regulation beginning decades prior to the onset of this study.

Universality of human microbial dynamics.

Human-associated microbial communities have a crucial role in determining our health and well-being, and this has led to the continuing development of microbiome-based therapies such as faecal microbiota transplantation. These microbial communities are very complex, dynamic and highly personalized ecosystems, exhibiting a high degree of inter-individual variability in both species assemblages and abundance profiles. It is not known whether the underlying ecological dynamics of these communities, which can be parameterized by growth rates, and intra- and inter-species interactions in population dynamics models, are largely host-independent (that is, universal) or host-specific. If the inter-individual variability reflects host-specific dynamics due to differences in host lifestyle, physiology or genetics, then generic microbiome manipulations may have unintended consequences, rendering them ineffective or even detrimental. Alternatively, microbial ecosystems of different subjects may exhibit universal dynamics, with the inter-individual variability mainly originating from differences in the sets of colonizing species. Here we develop a new computational method to characterize human microbial dynamics. By applying this method to cross-sectional data from two large-scale metagenomic studies--the Human Microbiome Project and the Student Microbiome Project--we show that gut and mouth microbiomes display pronounced universal dynamics, whereas communities associated with certain skin sites are probably shaped by differences in the host environment. Notably, the universality of gut microbial dynamics is not observed in subjects with recurrent Clostridium difficile infection but is observed in the same set of subjects after faecal microbiota transplantation. These results fundamentally improve our understanding of the processes that shape human microbial ecosystems, and pave the way to designing general microbiome-based therapies.

Pediatric electronic cigarette or vaping product use-associated lung injury (EVALI): updates in the coronavirus disease 2019 (COVID-19) pandemic era.

Electronic cigarette or vaping product use-associated lung injury (EVALI) is a toxic inhalational injury that surged in late 2019 and early 2020, immediately prior to the coronavirus disease 2019 (COVID-19) pandemic. Although EVALI cases have significantly decreased, they are still encountered, especially among adolescents. While several characteristic imaging findings and patterns of EVALI have been described, some of them can overlap with the imaging features of COVID-19 pneumonia. We provide a comprehensive review of EVALI that includes the latest updates and highlight the important role of radiologists as contributors to the appropriate and timely care of pediatric patients with this diagnosis.

Massively parallel screening of synthetic microbial communities.

Microbial communities have numerous potential applications in biotechnology, agriculture, and medicine. Nevertheless, the limited accuracy with which we can predict interspecies interactions and environmental dependencies hinders efforts to rationally engineer beneficial consortia. Empirical screening is a complementary approach wherein synthetic communities are combinatorially constructed and assayed in high throughput. However, assembling many combinations of microbes is logistically complex and difficult to achieve on a timescale commensurate with microbial growth. Here, we introduce the kChip, a droplets-based platform that performs rapid, massively parallel, bottom-up construction and screening of synthetic microbial communities. We first show that the kChip enables phenotypic characterization of microbes across environmental conditions. Next, in a screen of ∼100,000 multispecies communities comprising up to 19 soil isolates, we identified sets that promote the growth of the model plant symbiont Herbaspirillum frisingense in a manner robust to carbon source variation and the presence of additional species. Broadly, kChip screening can identify multispecies consortia possessing any optically assayable function, including facilitation of biocontrol agents, suppression of pathogens, degradation of recalcitrant substrates, and robustness of these functions to perturbation, with many applications across basic and applied microbial ecology.

A Comparison of Temperature Thresholds to Begin Laboratory Evaluation of Well-Appearing Febrile Infants.

OBJECTIVE: Young infants who develop fever are at an increased risk for serious infection. It is unclear, however, what temperature cutoff would be optimal to begin evaluating these infants because some criteria use different thresholds. We sought to determine the percentage of infants presenting to the Emergency Department (ED) with a temperature less than 38.2°C who develop serious infection compared with those with higher temperatures. METHODS: We used a publicly available dataset from the Pediatric Emergency Care Applied Research Network. Patients were included if they were aged 60 days or younger, had a documented rectal temperature of 38.0°C or higher in the ED or a history of fever within 24 hours before presentation to the ED, and were being evaluated for serious infection. We used the same exclusion criteria as the original Pediatric Emergency Care Applied Research Network study but further excluded those who were ill-appearing (Yale Observation Score > 10). Serious infections included any of the following: urinary tract infection, bacteremia, bacterial or herpes meningitis, bacterial pneumonia, or bacterial enteritis. Data were described using frequencies (percentages) and compared between groups using χ 2 test. RESULTS: Of the 4619 eligible infants, 1311 (28.4%) had a temperature lower than 38.2°C. Infants with temperatures lower than 38.2°C were significantly less likely to have a serious infection compared with those with higher temperatures (97 [7.5%] vs 365 [11.2%], P < 0.001). Of the infants with temperatures lower than 38.2°C who were tested, 67 (5.8%) had a urinary tract infection, 10 (0.8%) had bacteremia, 3 (0.4%) had bacterial meningitis, 3 (2.9%) had herpes meningitis, 17 (4.5%) had bacterial pneumonia, and 2 (4.8%) had bacterial enteritis. CONCLUSIONS: In this study, we found that infants with temperatures lower than 38.2°C were significantly less likely to have a serious infection than those with higher temperatures. Using an evaluation cutoff of 38.2°C, however, would likely miss a clinically important number of well-appearing infants with serious infections.

Identification of U83836E as a γ-glutamylcyclotransferase inhibitor that suppresses MCF7 breast cancer xenograft growth.

γ-Glutamylcyclotransferase (GGCT) is involved in glutathione homeostasis, in which it catalyzes the reaction that generates 5-oxoproline and free amino acids from γ-glutamyl peptides. Increasing evidence shows that GGCT has oncogenic functions and is overexpressed in various cancer tissues, and that inhibition of GGCT activity exerts anticancer effects in vitro and in vivo. Here, we demonstrate that U83836E ((2R)-2-[[4-(2,6-dipyrrolidin-1-ylpyrimidin-4-yl)piperazin-1-yl]methyl]-3,4-dihydro-2,5,7,8,-tetramethyl-2H-1-benzopyran-6-ol, dihydrochloride), a lazaroid that inhibits lipid peroxidation, inhibits GGCT enzymatic activity. U83836E was identified from a high-throughput screen of low molecular weight compounds using a fluorochrome-conjugated GGCT probe. We directly quantified that U83836E specifically inhibited GGCT by measuring the product of a fluorochrome-conjugated GGCT substrate assay, and showed that U83836E inhibited GGCT activity in extracts of NIH3T3 cells overexpressing GGCT. Moreover, U83836E significantly inhibited tumor growth in a xenograft model that used immunodeficient mice orthotopically inoculated with MCF7 human breast cancer cells. These results indicate that U83836E may be a useful GGCT inhibitor for the development of potential cancer therapeutics.

Microbial communities display alternative stable states in a fluctuating environment.

The effect of environmental fluctuations is a major question in ecology. While it is widely accepted that fluctuations and other types of disturbances can increase biodiversity, there are fewer examples of other types of outcomes in a fluctuating environment. Here we explore this question with laboratory microcosms, using cocultures of two bacterial species, P. putida and P. veronii. At low dilution rates we observe competitive exclusion of P. veronii, whereas at high dilution rates we observe competitive exclusion of P. putida. When the dilution rate alternates between high and low, we do not observe coexistence between the species, but rather alternative stable states, in which only one species survives and initial species' fractions determine the identity of the surviving species. The Lotka-Volterra model with a fluctuating mortality rate predicts that this outcome is independent of the timing of the fluctuations, and that the time-averaged mortality would also lead to alternative stable states, a prediction that we confirm experimentally. Other pairs of species can coexist in a fluctuating environment, and again consistent with the model we observe coexistence in the time-averaged dilution rate. We find a similar time-averaging result holds in a three-species community, highlighting that simple linear models can in some cases provide powerful insight into how communities will respond to environmental fluctuations.

Ovarian torsion: can we save the ovary?

OBJECTIVE: The purpose of this study is to evaluate the correlation between visually appearing ovarian necrosis and necrosis in histopathology in patients with ovarian torsion; and to identify predictive factors of ovarian necrosis. METHODS: This is a retrospective study. All women admitted to the hospital with a diagnosis of suspected ovarian torsion from January 2014 to December 2018 were recruited. Forty-two patients with a confirmed diagnosis of ovarian torsion were finally included. Correlation analysis was done between visual judgement of ovarian necrosis and necrosis in histopathology. Chi-square was performed to analyze dependence between time from pain onset to surgery, ovarian size in ultrasound, Doppler flow, and histopathological analysis. RESULTS: Thirty-one ovaries were visually judged as necrotic. Only five of them (16%) had histopathologically confirmed necrosis, 20 (64.5%) had hemorrhage or congestion, and 6 (19%) had normal ovarian tissue, p = 0.349. Development of ovarian necrosis showed to be dependent on time from onset of pain to surgery. All patients with necrotic ovaries in histopathology underwent surgery after 24 h of pain onset, while there was no necrosis in those who had surgery before 24 h. (p = < 0.05). There was no relationship between ovarian size measured by ultrasound and necrosis (p = 0.265), as well as color flow in ultrasound and necrosis (p = 0.388). CONCLUSION: Visual assessment of ovarian necrosis intraoperatively is not a good predictor of real necrosis in histopathology. To preserve the ovary, surgical management should not be delayed.

Telemedicine Medical Screening Evaluation Expedites the Initiation of Emergency Care for Children.

OBJECTIVE: Prior studies show that staffing a physician at triage expedites care in the emergency department. Our objective was to describe the novel application and effect of a telemedicine medical screening evaluation (Tele-MSE) at triage on quality metrics in the pediatric emergency department (PED). METHODS: We conducted a retrospective quasi-experimental pre-post intervention study of patients presenting to an urban PED from December 2017 to November 2019 who received a Tele-MSE at triage. We analyzed 4 diagnostic cohorts: gastroenteritis, psychiatry evaluation, burn injury, and extremity fracture. We matched cases with controls who received standard triage, from December 2015 to November 2017, by age, diagnosis, weekday versus weekend, and season of presentation. Outcome measures included door-to-provider time, time-to-intervention order, and PED length of stay (LOS). RESULTS: We included 557 patients who received Tele-MSE during the study period. Compared with controls, patients who received a Tele-MSE at triage had a shorter median door-to-provider time (median difference [MD], 8.4 minutes; 95% confidence interval [CI], 6.0-11.0), time-to-medication order (MD, 27.3 minutes; 95% CI, 22.9-35.2), time-to-consult order (MD, 10.0 minutes; 95% CI, 5.3-12.7), and PED LOS (MD, 0.4 hours; 95% CI, 0.3-0.6). CONCLUSIONS: A Tele-MSE is an innovative modality to expedite the initiation of emergency care and reduce PED LOS for children. This novel intervention offers potential opportunities to optimize provider and patient satisfaction and safety during the COVID-19 pandemic.

Pediatric Chest Radiographic and CT Findings of Electronic Cigarette or Vaping Product Use-associated Lung Injury (EVALI).

Background Electronic cigarette or vaping product use-associated lung injury (EVALI) is a serious public health concern with substantial morbidity and mortality, particularly in young individuals. Purpose To evaluate chest radiographic and chest CT findings of EVALI in the pediatric population. Materials and Methods This was a retrospective study of children who presented to a tertiary pediatric hospital from December 2018 to December 2019. Patients fulfilled the Centers for Disease Control and Prevention criteria for EVALI and had chest radiographs and CT images available at initial presentation. Two pediatric radiologists independently reviewed imaging for pattern, distribution, and extent of pulmonary abnormalities, as well as for extrapulmonary abnormalities. Clinical information, management, and outcomes were reviewed. Interobserver agreement was measured with Cohen κ coefficient. Results Seven male patients (50%) and seven female patients (50%) (mean age, 16 years; range, 13-18 years) were evaluated. All patients underwent chest radiography and CT within 4 days of presentation (range, 0-4 days). Chest radiographic findings included ground-glass opacity in 14 of 14 (100%) and consolidation in eight of 14 (57%). CT findings included ground-glass opacity in 14 of 14 (100%), consolidation in nine of 14 (64%), and interlobular septal thickening in two of 14 (14%). At CT, subpleural sparing was seen in 11 of 14 (79%) and a reversed halo sign was seen in five of 14 (36%). Chest radiographic and CT abnormalities were predominately bilateral in 14 of 14 (100%) and symmetric in 13 of 14 (93%), with lower lobe predominance in seven of 14 (50%). Extent of abnormality was predominately diffuse at both chest radiography and CT. There was almost perfect interobserver agreement between two reviewers for detecting abnormalities on chest radiographs (κ = 0.99; 95% confidence interval: 0.97, 1.00) and CT (κ = 0.99; 95% confidence interval: 0.98, 1.00). Conclusion In pediatric patients, electronic cigarette or vaping product use-associated lung injury is characterized by bilateral symmetric ground-glass opacities, consolidation, and a lower lobe predominance at CT. © RSNA, 2020.

Mitochondrial form and function.

Mitochondria are one of the major ancient endomembrane systems in eukaryotic cells. Owing to their ability to produce ATP through respiration, they became a driving force in evolution. As an essential step in the process of eukaryotic evolution, the size of the mitochondrial chromosome was drastically reduced, and the behaviour of mitochondria within eukaryotic cells radically changed. Recent advances have revealed how the organelle's behaviour has evolved to allow the accurate transmission of its genome and to become responsive to the needs of the cell and its own dysfunction.