Transcriptional and hormonal profiling uncovers the interactions between plant developmental stages and RNA virus infection.

Arabidopsis thaliana is more susceptible to certain viruses during its later developmental stages. The differential responses and the mechanisms behind this development-dependent susceptibility to infection are still not fully understood. Here we explored the outcome of a viral infection at different host developmental stages by studying the response of A. thaliana to infection with turnip mosaic virus at three developmental stages: juvenile vegetative, bolting, and mature flowering plants. We found that infected plants at later stages downregulate cell wall biosynthetic genes and that this downregulation may be one factor facilitating viral spread and systemic infection. We also found that, despite being more susceptible to infection, infected mature flowering plants were more fertile (i.e. produce more viable seeds) than juvenile vegetative and bolting infected plants; that is, plants infected at the reproductive stage have greater fitness than plants infected at earlier developmental stages. Moreover, treatment of mature plants with salicylic acid increased resistance to infection at the cost of significantly reducing fertility. Together, these observations support a negative trade-off between viral susceptibility and plant fertility. Our findings point towards a development-dependent tolerance to infection.

Kin selection favors religious traditions: ancestor worship as a cultural descendant-leaving strategy.

Recent years have seen renewed interest in the role of religious systems as drivers of the evolution of cooperation in human societies. One suggestion is that a cultural tradition of ancestor worship might have evolved as a "descendant-leaving strategy" of ancestors by encouraging increased altruism particularly between distant kin. Specifically, Coe and others have suggested a mechanism of cultural transmission exploiting social learning biases, whereby ancestors have been able to establish parental manipulation of kin recognition and perceived relatedness as a traditional behavior, leading to increased altruism among co-descendants and thereby maximizing the ancestor's long-term inclusive fitness. Here, we develop a demographically explicit model in order to quantify the resulting increase in altruism and concomitant "ancestor-descendant conflict", and to determine the evolutionary feasibility of religiously motivated cultural norms that promote altruism among co-descendants. Our analysis reveals that such norms could indeed drive an overall increase in altruism with potential for ancestor-descendant conflict, particularly in low-dispersal settings. Moreover, we find that natural selection can favor traditions encouraging increased altruism towards co-descendants under a range of conditions, with the inclusive-fitness costs of enacting an inappropriately high level of altruism being offset by inclusive-fitness benefits derived from the cultural tradition facilitating kin recognition.

Associations Between Fundamental Motor Skill Domains and Physical Fitness Components in 5-11-Year-Old Children.

High competence in fundamental motor skills (FMS) and adequate physical fitness (PF) levels are a solid foundation for acquiring an active and healthy lifestyle during childhood and adolescence. In this cross-sectional study, we aimed to compare gender and age groups and identify correlations between FMS and PF in young elementary school students. We used a structured questionnaire to gather sociodemographic information from parents, and we characterized the children's economic profile with the Brazil Social Economic Status Criterion. We collected FMS data using the Furtado-Gallagher Children Observational Movement Pattern Assessment System (FG-COMPASS), and we used the Brazil Sports Project Battery Test to measure PF levels. Statistical analyses involved descriptive data and inferential tests to determine group differences in FMS and PF levels. Hierarchical regression helped identify the associations between FMS and PF, as controlled by sociodemographic factors. Participants were 720 students (and parents) of both genders (383 girls, 337 boys; M age = 8.8, SD = 1.52 years) from grades 1 to 5 in an elementary school in a municipality in the western region of the Paraná state in Brazil. The results showed significant differences in children's motor skills and PF based on gender and age. The hierarchical regression model showed different combinations of flexibility, abdominal resistance, upper limb strength, agility, speed, and lower limb strength, which explained 33.7% of the variability in the global FMS index, 41% of the variability in manipulative skills, and 12.7% of the variability in locomotor skills. In addition, there was a positive association between FMS and PF related to neuromuscular development for both sexes, regardless of age.

Poor stress resilience in adolescence predicts higher risk of severe COVID-19 and other respiratory infections: A prospective cohort study of 1.4 million Swedish men.

OBJECTIVES: To investigate the associations between stress resilience in late adolescence and later risk of severe COVID-19 and other lower respiratory infections. A secondary aim was to examine potential confounding between low cardiorespiratory fitness (CRF) and stress resilience in relation to respiratory infection. METHODS: We conducted a registry-based cohort study of 1.4 million Swedish men, undergoing military conscription between 1968 and 2005. All were assessed by a psychologist for stress resilience, receiving a score between 1 and 9. The outcomes were hospitalization or death due to COVID-19 from March 2020 to September 2021 and hospitalization due to bacterial or viral pneumonia from conscription until January 2020. A secondary aim was to examine potential confounding between low cardiorespiratory fitness (CRF) and stress resilience in relation to respiratory infection. RESULTS: Poor stress resilience in late adolescence is associated with later risk of severe lower respiratory infections. Using a high resilience score as the reference, the hazard ratio (95 % CI) for death due to COVID-19 for the lowest scores was 1.49 (1.01-2.18) adjusted for CRF and other confounders. The corresponding adjusted hazard ratios for hospitalization due to bacterial pneumonia were 2.28 (2.03-2.57) and for viral pneumonia 1.92 (1.33-2.79). No significant interaction was seen between stress resilience and CRF in the analysis. CONCLUSIONS: Poor stress resilience is a prospective factor for severe COVID-19 as well as for bacterial and viral respiratory pneumonia endpoints, independent of CRF. These findings imply an effect of late adolescent stress resilience on the immune system later in life.

Kin selection as a modulator of human handedness: sex-specific, parental and parent-of-origin effects.

The frequency of left-handedness in humans is ~10% worldwide and slightly higher in males than females. Twin and family studies estimate the heritability of human handedness at around 25%. The low but substantial frequency of left-handedness has been suggested to imply negative frequency-dependent selection, e.g. owing to a 'surprise' advantage of left-handers in combat against opponents more used to fighting right-handers. Because such game-theoretic hypotheses involve social interaction, here we perform an analysis of the evolution of handedness based on kin-selection, which is understood to play a major role in the evolution of social behaviour generally. We show that: (1) relatedness modulates the balance of right-handedness vs. left-handedness, according to whether left-handedness is marginally selfish vs. marginally altruistic; (2) sex differences in relatedness to social partners may drive sex differences in handedness; (3) differential relatedness of parents and offspring may generate parent-offspring conflict and sexual conflict leading to the evolution of maternal and paternal genetic effects in relation to handedness; and (4) differential relatedness of maternal-origin vs. paternal-origin genes may generate intragenomic conflict leading to the evolution of parent-of-origin-specific gene effects - such as 'genomic imprinting' - and associated maladaptation.

Effect of post COVID-19 on body composition, physical fitness, sleep quality and quality of life among young adults: a cross-sectional study of matched pairs.

Background: Coronavirus 2019 (COVID-19) causes lung tissue inflammation, affects mental health, and disturbs sleep and the musculoskeletal system. This study aimed to investigate the effects of COVID-19 on physical function and quality of life by comparing the body composition, physical fitness, sleep quality and quality of life between Thai young adults with and without post COVID-19 infection. Methods: A cross-sectional study was comprised of two matched groups (post COVID-19 group and non COVID-19 group) with 36 participants in each group. Data about body composition, physical fitness, sleep quality and quality of life were collected using the bioelectrical impedance analysis, the 1-min sit-to-stand test, the hand grip strength test, the Pittsburgh sleep quality questionnaire and the EuroQol-5D-5L, respectively. Independent samples T-test, Mann-Whitney U test and Chi-square test were used to compare between the two groups. Results: The changes in oxygen saturation and respiratory rate after the physical fitness test and the sleep quality analysis showed a statistically significant difference between the groups with and without post COVID-19 infection (p = 0.006, p = 0.003 and p = 0.003, respectively). However, quality of life and body composition were not significantly different between groups. Conclusions: COVID-19 influenced the changes in oxygen saturation and respiratory rate after the physical fitness test and the sleep quality analysis in young adults. The results should be utilized to facilitate physical rehabilitation for COVID-19-infected individuals following infection. Those who have not been infected with COVID-19 must be informed of self-protection measures to avoid contracting the virus.

Molecular insights into the evolutionary trajectory of a Klebsiella aerogenes clinical isolate with a complex trade-off between resistance and virulence.

The fitness cost associated with antimicrobial resistance has an important influence on evolutionary dynamics. We compared the genomes of three Klebsiella aerogenes isolates recovered from blood samples or deep abscess cultures from the same patient: the wild-type strain (CT_WT), a piperacillin-tazobactam-resistant strain (CT_PENI), and an extended-spectrum-cephalosporin (ESC)-resistant strain (CT_R). Whole-genome sequencing revealed that CT_PENI had acquired a TEM-1 ß-lactamase with a mutated promoter, accounting for overproduction. CT_PENI then acquired an E240G substitution in the TEM-1 ß-lactamase (resulting in TEM-207) and lost the porin-encoding ompK36 gene to give CT_R. All three strains showed the same virulence in a mouse model of intraperitoneal infection. The results of recombination and transformation assays indicated that when present separately, the TEM-207 overproduction and the ompK36 gene deletion had only small effects on susceptibility to ESCs. However, the combination of the two changes led to a much lower susceptibility to ESCs. Moreover, the levels of fitness in vitro and in vivo in a murine model of gut colonization were significantly lower after TEM-1 ß-lactamase overproduction and lower still after E240G substitution and OmpK36 loss. We hypothesize that the chosen courses of antibiotics led to the stepwise emergence of a clone with resistance to penicillins and ESCs and no loss of virulence. However, acquired resistance may have a fitness cost that limits evolutionary success. Our results might explain why the overproduction of extended-spectrum ß-lactamases (which should confer a high level of piperacillin-tazobactam resistance) is not observed in clinical practice and why TEM-207 has rarely been detected in clinical isolates.

Exploring job satisfaction in fitness franchises: a study from a human talent perspective.

This qualitative study investigates job satisfaction and its impact on the performance of human talent in fitness club franchises in Mexico, based on six semi-structured in-depth interviews conducted in October 2023. The research highlights that internal communication is the primary factor influencing job satisfaction, followed by interpersonal relationships and organisational climate. These findings imply that enhancing internal communication and fostering healthy interpersonal relationships can significantly improve employee well-being and job performance. The study aims to understand job satisfaction from the human talent perspective, focusing on the factors that affect their satisfaction and performance. The insights gained can inform strategies to improve work life quality and industry efficiency in Mexico, serving as a benchmark for future research and a strategic tool for human resource management in similar organisations.

Variation in parental investment preferences for nestlings of the Gray-backed Shrike (Lanius tephronotus) in alpine environments.

In the northeastern edge of the Qinghai-Tibet Plateau, the Gray-backed Shrike, a shrubland bird species of the plateau, confronts harsh living conditions. The impact of such an environment on their reproductive strategies has long intrigued us. This study reveals significant environmental effects on the investment of the Gray-backed Shrike during their nestling-rearing and egg-laying stages. (1) Based on measurements of 215 shrike eggs from 2017 to 2021, we found that under the cold alpine climate, Gray-backed Shrikes opt for a strategy of larger clutches and bigger eggs as average rainfall decreases. Concurrently, parents display a decreasing hatching order strategy, resulting in significant weight differences among newly hatched nestlings. (2) Marginal and core offspring exhibited no significant differences in fledging conditions. Core offspring generally have a slightly larger physique than marginal ones. However, marginal offspring exhibit the highest growth rate, with similar survival rates across different offspring categories. Parental rearing adopts a nest survival strategy. (3) The food provisioning rate by parents correlates strongly with the number of nestlings, the age of the nestling, and the nest's sex ratio. Differences exist between female and male provisioning rates based on begging intensity and average temperature; higher average temperatures lead to more food, with males providing more food. (4) Factors like nest sex ratio, offspring category, nestling age, and nestling sex influence the feeding preferences of parents. When overall nestling ratios skew towards either male or female, parental feeding preferences align with the actual nest sex ratio. Male and female parental feeding preferences differ based on average temperature and nestling sex. Males consistently exhibit a stronger preference for feeding male nestlings, regardless of the nest's sex ratio. In contrast, females don't show a clear preference, leading to differences in survival rates for different nestling sex under male feeding preferences.

Determinants of cerebral blood flow and arterial transit time in healthy older adults.

Cerebral blood flow (CBF) and arterial transit time (ATT), markers of brain vascular health, worsen with age. The primary aim of this cross-sectional study was to identify modifiable determinants of CBF and ATT in healthy older adults (n = 78, aged 60-81 years). Associations between cardiorespiratory fitness and CBF or ATT were of particular interest because the impact of cardiorespiratory fitness is not clear within existing literature. Secondly, this study assessed whether CBF or ATT relate to cognitive function in older adults. Multiple post-labelling delay pseudo-continuous arterial spin labelling estimated resting CBF and ATT in grey matter. Results from multiple linear regressions found higher BMI was associated with lower global CBF (ß = -0.35, P = 0.008) and a longer global ATT (ß = 0.30, P = 0.017), global ATT lengthened with increasing age (ß = 0.43, P = 0.004), and higher cardiorespiratory fitness was associated with longer ATT in parietal (ß = 0.44, P = 0.004) and occipital (ß = 0.45, P = 0.003) regions. Global or regional CBF or ATT were not associated with processing speed, working memory, or attention. In conclusion, preventing excessive weight gain may help attenuate age-related declines in brain vascular health. ATT may be more sensitive to age-related decline than CBF, and therefore useful for early detection and management of cerebrovascular impairment. Finally, cardiorespiratory fitness appears to have little effect on CBF but may induce longer ATT in specific regions.

Feeding behavior, life-history traits, and settling preference of Aulacorthum solani (Hemiptera: Aphididae) on resistant and susceptible soybeans.

Foxglove aphid, Aulacorthum solani Kaltenbach (Hemiptera: Aphididae), is a major pest worldwide. It can infest various crops, including soybean, and reduce yields. The use of insect-resistant cultivars can effectively manage pests. Dowling is a soybean cultivar that can control Aphis glycines through antibiosis and antixenosis. In this study, we investigated the feeding behavior of A. solani using electropenetrography (EPG), and its life-history traits using an age-stage, two-sex life table, and its settling preferences on Dowling (resistant) and Heinong 51 (HN51, susceptible) soybean cultivars. The Dowling cultivar showed strong antibiosis against A. solani. Aphids feeding on Dowling exhibited significantly reduced survival, fecundity, and longevity, and increased nymph duration. Moreover, Dowling had negative impacts on the demographic parameters of the aphids. The number of A. solani individuals was significantly less on Dowling than on HN51, indicating the antixenotic effects of Dowling. As shown using EPG, the mechanical blocking wave (F) of A. solani was significantly longer after feeding on Dowling than after feeding on HN51, indicating that Dowling has a higher mechanical resistance. In conclusion, Dowling exhibited strong resistance to A. solani. These results are beneficial for integrated pest management in soybean fields and breeding programs.

Transfer dynamics of antimicrobial resistance among gram-negative bacteria.

Antimicrobial resistance (AMR) in gram-negative bacteria (GNBs) is a significant global health concern, exacerbated by mobile genetic elements (MGEs). This review examines the transfer of antibiotic resistance genes (ARGs) within and between different species of GNB facilitated by MGEs, focusing on the roles of plasmids and phages. The impact of non-antibiotic chemicals, environmental factors affecting ARG transfer frequency, and underlying molecular mechanisms of bacterial resistance evolution are also discussed. Additionally, the study critically assesses the impact of fitness costs and compensatory evolution driven by MGEs in host organisms, shedding light on the transfer frequency of ARGs and host evolution within ecosystems. Overall, this comprehensive review highlights the factors and mechanisms influencing ARG movement among diverse GNB species and underscores the importance of implementing holistic One-Health strategies to effectively address the escalating public health challenges associated with AMR.

Modification of the Diabetes Prevention Program Lifestyle Intervention in Persons with Spinal Cord Injury: Efficacy for Reducing Major Cardiometabolic Risks, Increased Fitness, and Improved Health-Related Quality of Life.

Individuals with chronic spinal cord injury (SCI) face elevated risks of cardiometabolic diseases, including cardiovascular disease and type 2 diabetes, due to factors like physical inactivity, neurogenic obesity, and disrupted glucose and insulin regulation. We conducted a prospective intervention cohort study involving 20 individuals with SCI (aged 28-60) with neurologic injuries at levels C4-T10 and ASIA scale grades A-D, lasting over a year. Our study assessed the impact of a therapeutic lifestyle intervention (TLI) based on the Diabetes Prevention Program (DPP) and its maintenance phase. The TLI comprised circuit resistance training, a Mediterranean-style calorie-restricted diet, and tailored behavioral support. Key outcomes measured included cardiometabolic risks (plasma analytes and disease biomarkers), anthropometrics (body mass, BMI, tissue composition), global metabolism, fitness (aerobic capacity, peak strength), and health-related quality of life (SF36). Results demonstrated a significant reduction in body mass and BMI by 7.5%, a 7% decrease in total fat mass, and substantial improvements in glucose regulation and insulin sensitivity. Lipid profiles improved, with reduced total cholesterol, triglycerides, and LDL-C, and increased HDL-C. Resting energy expenditure and fat oxidation increased by 27.4% and 58.5%, respectively. Aerobic capacity and dynamic strength also improved significantly. The Physical and Mental Composite Scores of the SF36 improved by 22.8% and 30.5%, respectively. Following the maintenance phase, several positive outcomes persisted, indicating a reduction in risk for cardiovascular disease and comorbid disorders. Our findings support the effectiveness of TLI in reducing cardiometabolic risks, enhancing fitness, and improving health-related quality of life in individuals with chronic SCI. Trial Registration: ClinicalTrials.gov, ID: NCT02853149 Registered August 2, 2016.

Effects of Swimming Exercise on Early Adolescents' Physical Conditioning and Physical Health: A Systematic Review.

BACKGROUND/OBJECTIVES: Swimming is a popular and cost-effective way to prevent sedentary behavior and improve physical conditioning and health during early adolescence. However, information on its impact and benefits on daily life activities is lacking. This systematic review aims to summarize the chronic effects of swimming on physical conditioning and physical health outcomes in early adolescents. METHODS: The PRISMA 2020 guidelines were followed and PubMed, Scopus, Web of Science, and International Symposium of Biomechanics and Medicine in Swimming proceedings databases were searched. Eligibility criteria were defined on the PICOS framework (healthy adolescents in early puberty, swimming programmes or training, passive or active control groups, general effects on physical conditioning or health, longitudinal) and risk of bias was assessed using RoBANS 2. RESULTS: From 2365 records, 20 non-randomized studies met the defined criteria. High heterogeneity in sample size and intervention was observed. While studies related to physical conditioning (n = 5) focused on physiological variables and muscular function, the evidence regarding physical health outcomes (n = 15) explored bone accrual, haemodynamics, body composition, musculoskeletal system, and lung growth. High overall risk of bias (70%) was observed due to strict criteria. CONCLUSIONS: Swimming exercise seems to improve cardiorespiratory fitness, cardiac output, haemodynamics, heart growth, motor performance, and body composition of early adolescents. Despite clear evidence that exists on these chronic effects, research on bone health, postural deficit, motor skills, and sleep quality is still missing.

Physiological Profile Assessment and Self-Measurement of Healthy Students through Remote Protocol during COVID-19 Lockdown.

Background: The COVID-19 pandemic has led to reduced physical activity and increased sedentary behaviors, negatively impacting mental and physical health. Engaging in physical activity at home during quarantine became essential to counteracting these adverse effects. To develop appropriate physical activity programs, assessing individuals' fitness levels and the impact of inactivity is crucial. This study aims to compare motor abilities-including flexibility, balance, reaction time, cardiovascular endurance, and lower and upper limb strength-assessed both in-person and remotely, to determine the accuracy and repeatability of self-administered tests. Methods: A total of 35 young subjects (age 24.2 ± 1.97 years, BMI 22.4 ± 2.61 kg/m2) participated in this study. Each participant underwent a battery of motor ability tests designed to assess various fitness components. The tests were administered twice for each subject: once in a laboratory setting and once remotely at home. The sequence of tests was randomly assigned to ensure unbiased results. Both the in-person and remote assessments were used to evaluate the accuracy and reliability of self-administered tests. Results: The comparison of test results between the laboratory and remote settings revealed percentage differences ranging from 5% to 10%. This variation is considered an acceptable margin of error, suggesting that the tests conducted remotely were relatively accurate when compared to those performed in a controlled laboratory environment. Conclusions: The findings indicate that remote fitness testing is a promising method for evaluating motor abilities. With an acceptable margin of error, remote assessments can be effectively used to personalize training programs based on individuals' physiological characteristics. This approach may be particularly beneficial during times of limited access to fitness facilities, such as during quarantine, or for individuals seeking more flexible fitness evaluation methods.

Grip strength of law enforcement officers and its implications.

Grip strength (GS) plays a vital role for law enforcement officers (LEOs). This study aimed to establish a baseline for LEO GS, compare it with the general population, determine the correlation between LEO GS and body dimensions, and evaluate the implications for occupational performance. A total of 756 male and 218 female LEOs from across the U.S. participated in the study. On average, male LEOs exhibit stronger GS (49.53 kg) than female officers (32.14 kg). Significant differences between LEOs and the general population were observed. GS correlated with hand breadth, hand length, stature, and bideltoid breadth. Approximately 26%-46% of males and 5%-39% of females were identified as being at risk of health, fit, or occupational performance based on their measured GS. Enhancing GS training or avoiding implementing heavy equipment (such as pistols with heavy trigger weight), could improve officer occupational performance, safety, or health.

Inheritance of chlorantraniliprole resistance and fitness costs in a field population of Cnaphalocrocis medinalis (Lepidoptera: Pyralidae) in China.

BACKGROUND: Cnaphalocrocis medinalis is one of the major rice insect pests in Asia. Chlorantraniliprole is one of the most important insecticides for the control of C. medinalis. In this study, a field-resistant population and a susceptible strain of C. medinalis were used to evaluate the inheritance of chlorantraniliprole resistance and fitness costs in the field. RESULTS: The field-resistant population (Cm-RR) showed 128.4-fold resistance to chlorantraniliprole compared with the susceptible strain (Cm-SS). The dose-response of reciprocal cross progeny (F1 and F1') showed no significant difference, which indicated the inheritance of resistance to chlorantraniliprole in C. medinalis was autosomal. The degrees of dominance (D) of resistance for F1 and F1' were -0.19 and -0.05, respectively, indicating that the chlorantraniliprole resistance of C. medinalis was incompletely recessive inheritance. At the same time, significant differences between observed and expected mortalities of self-cross (F2 and F2') and backcross (BC and BC') progenies suggested chlorantraniliprole resistance is controlled by multiple genes. Furthermore, the Cm-RR population had a relative fitness of 0.32 with a substantially decreased pupation rate, emergence rate, fecundity, and substantially increased developmental time of larval and pupa stages. CONCLUSION: Current research showed that the inheritance of chlorantraniliprole resistance to C. medinalis was autosomal, incompletely recessive and multigene. The field-resistant population had a relative fitness of 0.32 when compared with the susceptible strain. This study provided valuable information for facilitating the development of chlorantraniliprole resistance management strategies. © 2024 Society of Chemical Industry.

Association between cardiorespiratory fitness and trend of age-related rise in arterial stiffness in individuals with and without hypertension or diabetes.

BACKGROUND: This study aimed to investigate whether higher cardiorespiratory fitness (CRF) can modify the trend of age-related rise in arterial stiffness in individuals with and without hypertension (HTN) or diabetes. METHODS: The study included 4,935 participants who underwent maximal cardiopulmonary exercise testing with respiratory gas analysis in a health screening program. CRF was directly measured using peak oxygen uptake during the cardiopulmonary exercise test, while arterial stiffness was evaluated using brachial-ankle pulse wave velocity (baPWV). RESULTS: Participants with high CRF levels had significantly lower baPWV compared to those with low CRF levels, regardless of HTN or diabetes status (p<0.05). The trend of baPWV increased with age, but the rate of age-related increase in baPWV was lower in individuals with moderate to high CRF levels compared to those with low CRF levels, regardless of HTN or diabetes status. Joint association analysis indicated that the trend of age-related increase in baPWV was the lowest in fit individuals without HTN or diabetes compared to unfit individuals with HTN or diabetes (p<0.01). However, the trend of age-related increase in baPWV was not attenuated in fit with HTN or diabetes compared to unfit with HTN or diabetes. CONCLUSIONS: These findings suggest that higher CRF levels may mitigate the trend of age-related rise in arterial stiffness in individuals with and without HTN or diabetes. However, this attenuating trend appears more pronounced in individuals without HTN or diabetes.

The energy metabolism of Cupriavidus necator in different trophic conditions.

The "knallgas" bacterium Cupriavidus necator is attracting interest due to its extremely versatile metabolism. C. necator can use hydrogen or formic acid as an energy source, fixes CO2 via the Calvin-Benson-Bassham (CBB) cycle, and grows on organic acids and sugars. Its tripartite genome is notable for its size and duplications of key genes (CBB cycle, hydrogenases, and nitrate reductases). Little is known about which of these isoenzymes and their cofactors are actually utilized for growth on different substrates. Here, we investigated the energy metabolism of C. necator H16 by growing a barcoded transposon knockout library on succinate, fructose, hydrogen (H2/CO2), and formic acid. The fitness contribution of each gene was determined from enrichment or depletion of the corresponding mutants. Fitness analysis revealed that (i) some, but not all, molybdenum cofactor biosynthesis genes were essential for growth on formate and nitrate respiration. (ii) Soluble formate dehydrogenase (FDH) was the dominant enzyme for formate oxidation, not membrane-bound FDH. (iii) For hydrogenases, both soluble and membrane-bound enzymes were utilized for lithoautotrophic growth. (iv) Of the six terminal respiratory complexes in C. necator H16, only some are utilized, and utilization depends on the energy source. (v) Deletion of hydrogenase-related genes boosted heterotrophic growth, and we show that the relief from associated protein cost is responsible for this phenomenon. This study evaluates the contribution of each of C. necator's genes to fitness in biotechnologically relevant growth regimes. Our results illustrate the genomic redundancy of this generalist bacterium and inspire future engineering strategies.IMPORTANCEThe soil bacterium Cupriavidus necator can grow on gas mixtures of CO2, H2, and O2. It also consumes formic acid as carbon and energy source and various other substrates. This metabolic flexibility comes at a price, for example, a comparatively large genome (6.6 Mb) and a significant background expression of lowly utilized genes. In this study, we mutated every non-essential gene in C. necator using barcoded transposons in order to determine their effect on fitness. We grew the mutant library in various trophic conditions including hydrogen and formate as the sole energy source. Fitness analysis revealed which of the various energy-generating iso-enzymes are actually utilized in which condition. For example, only a few of the six terminal respiratory complexes are used, and utilization depends on the substrate. We also show that the protein cost for the various lowly utilized enzymes represents a significant growth disadvantage in specific conditions, offering a route to rational engineering of the genome. All fitness data are available in an interactive app at https://m-jahn.shinyapps.io/ShinyLib/.