Nutritional Environment Research Articles

12246 The Stage-Dependent Transcriptome And Methylome Reveal Significance Of The Neonatal Period In Postnatal Metabolic Maturation Of The Mouse Liver

Abstract Disclosure: S. Yano: None. N. Sato: None. H. Araki: None. F. Miura: None. T. Ito: None. Y. Ogawa: None. The mammalian liver serves as an extramedullary hematopoietic organ during the fetus and matures into a metabolic organ after birth, adapting to changes in the nutritional environment. DNA demethylation upregulates fatty acid β-oxidation (FAO) genes in the postnatal mouse liver to produce energy from breast milk lipids. However, the detailed interactions between DNA methylation (DNAme) and gene expression through the perinatal stages remain poorly understood. Here, we perform an integrative analysis of the transcriptome and methylome of the mouse liver at the fetal, neonatal, and postweaning stages. We found a drastic loss of DNAme at the neonatal stage in specific regions associated with metabolic pathways such as FAO and gluconeogenesis in concordance with the activation of metabolic processes. Moreover, in silico analysis predicted transcription factors including HNF4α, PPARα, and NR1H2 as key epigenetic regulators within the neonatal period. We also observed an inactivation of erythrocyte development with a concordant gain of DNAme. This analysis extends the epigenetic landscape of postnatal hepatic maturation, suggesting the importance of the nutritional environment during the neonatal period for epigenetic regulation. Presentation: 6/3/2024

Predicting frailty domain impairments and mortality with the Hospital Frailty Risk Score among older adults with cancer: the ELCAPA-EDS cohort study.

Automated frailty screening tools like the Hospital Frailty Risk Score (HFRS) are primarily validated for care consumption outcomes. We assessed the predictive ability of the HFRS regarding care consumption outcomes, frailty domain impairments and mortality among older adults with cancer, using the Geriatric 8 (G8) screening tool as a clinical benchmark. This retrospective, linkage-based study included patients aged ≥70years with solid tumor, enrolled in the Elderly Cancer Patients (ELCAPA) multicentre cohort study (2016-2020) and hospitalized in acute care within the Greater Paris University Hospitals. HFRS scores, which encompass hospital-acquired problems and frailty-related syndromes, were calculated using data from the index admission and the preceding 6months. A multidomain geriatric assessment (GA), including cognition, nutrition, mood, functional status, mobility, comorbidities, polypharmacy, incontinence, and social environment, was conducted at ELCAPA inclusion, with computation of the G8 score. Logistic and Cox regressions measured associations between the G8, HFRS, altered GA domains, length of stay exceeding 10days, 30-day readmission, and mortality. Among 587 patients included (median age 82years, metastatic cancer 47.0%), 237 (40.4%) were at increased frailty risk by the HFRS (HFRS>5) and 261 (47.5%) by the G8 (G8≤10). Both HFRS and G8 were significantly associated with cognitive and functional impairments, incontinence, comorbidities, prolonged length of stay, and 30-day mortality. The G8 was associated with polypharmacy, nutritional and mood impairment. Although showing significant associations with short-term care consumption, the HFRS could not identify polypharmacy, nutritional, mood and social environment impairments and showed low discriminatory ability across all GA domains.

A two-front nutrient supply environment fuels small intestinal physiology through differential regulation of nutrient absorption and host defense

The small intestine contains a two-front nutrient supply environment created by luminal dietary and microbial metabolites (enteral side) and systemic metabolites from the host (serosal side). Yet, it is unknown how each side contributes differentially to the small intestinal physiology. Here, we generated a comprehensive, high-resolution map of the small intestinal two-front nutrient supply environment. Using invivo tracing of macronutrients and spatial metabolomics, we visualized the spatiotemporal dynamics and cell-type tropism in nutrient absorption and the region-specific metabolic heterogeneity within the villi. Specifically, glutamine from the enteral side fuels goblet cells to support mucus production, and the serosal side loosens the epithelial barrier by calibrating fungal metabolites. Disorganized feeding patterns, akin to the human lifestyle of skipping breakfast, increase the risk of metabolic diseases by inducing epithelial memory of lipid absorption. This study improves our understanding of how the small intestine is spatiotemporally regulated by its unique nutritional environment.

A mixed-method evaluation of the New York State Healthy Pantry Initiative: application of the SNAP-Ed evaluation framework

ABSTRACT Food pantry nutrition environments are important settings for improving access to healthful foods among food-insecure populations. The Healthy Pantry Initiative (HPI) used policy, systems, and environmental (PSE) changes to improve the food pantry nutrition environment from October 2018 through September 2019. Program implementers assessed the need for PSE changes, developed action plans, and collected baseline, implementation, and follow-up data. Guided by the SNAP-Ed Evaluation framework, the collected data were used to capture information about HPI need, planning, adoption, implementation, and reach, from the perspective of frontline nutrition educators.

Rethinking the Social Determination of Food in Chile Through Practices and Interactions of Actors in Food Environments: Nonexperimental, Cross-Sectional Study.

Food environments are crucial for promoting healthy and sustainable eating and preventing obesity. However, existing food environment frameworks assume an already installed causality and do not explain how associations in food environments are established or articulated, especially from an integrative and transdisciplinary approach. This research attempts to bridge these gaps through the use of Actor-Network Theory, which traces the relationship network between human (and nonhuman) actors in order to describe how these interact and what agencies (direct or remote) are involved. This study aims to explain the practices and interactions of actors in food environments in order to approach the problem of unhealthy eating with a transdisciplinary approach. This is a nonexperimental, cross-sectional study. Due to the complexity of the study phenomena, a mixed methods approach with 4 consecutive phases will be developed in Chile. Phase 1 involves a systematic literature review of food environment evidence since 2015, following the PRISMA (Preferred Reporting Items for Systematic Reviews and Meta-Analyses) protocol; phase 2 involves the application of a shortened version of the Nutrition Environment Measure Scale-Perceptions adapted to Chile (NEMS-P-Ch) in 2 neighborhoods with different socioeconomic levels; in phase 3, six focus groups in each neighborhood will be conducted to address social determinants such as gender, employment status, and migration; and in phase 4, participant observation and in-depth interviews will be used to analyze the direct and empirical exploration of the actors in their daily interaction with food environments. The triangulation and complementarity of the data will allow us to create a practical model about the practices and interactions of actors in their food environments, which reflects the complexity and transdisciplinary nature of the study. We have advanced in phases 1-3 of the study. In phase 1, a total of 109 manuscripts are being revised for data extraction. In phase 2, we applied the NEMS-P-Ch to 785 people, 49.4% (388/785) of whom belong to a low socioeconomic neighborhood. Participants from phase 2 are being contacted to participate in the focus groups (phase 3). By the end of July, we have conducted 6 focus groups with 5-11 participants. This study will provide a comprehensive understanding of how individuals interact with their food environments, offering deep insights into the factors influencing their food-related decisions. In addition, the study aims to develop a model that more accurately reflects reality by examining not only the food environments themselves but also the interactions among various stakeholders within these environments and their daily practices. The findings of this study will offer evidence-based insights to inform public policies tailored to the specific territories and communities under investigation or those with similar characteristics. DERR1-10.2196/62765.

Healthy eating in globalized food environments: market access and consumer behavior in the Galápagos Islands of Ecuador

Abstract Food environments are the interface between food systems and consumers. Although market access contributes to diet intake, consumer behavior determines food acquisition practices yet is often neglected in food environment research. Implementing sustainable food system transformations in climate-vulnerable, trade-dependent settings requires effective integration of both geographic and experienced-based measures of access. This study in the Galápagos Islands (i) develops measures for geographic and experience-based food environments (EFEs) and (ii) links diet outcomes to these food environment measures independently and when interacted. Cross-sectional household data including diet recalls come from 388 participants in the Healthy Family Study from San Cristóbal Island, Galápagos in 2018. Geocoded market inventory and price data were obtained in 2018 using the Nutritional Environment Measurement Survey for Stores (n = 60). Geographic food environments were created from market scores and distribution. EFEs were based on factor analyzed consumer behavior strategies. Diet quality was defined using the global dietary recommendations score. Adjusted linear regressions tested the relationships between diet and food environment measures and included sociodemographic covariates. Interactions between geographic and EFEs were tested. This study showed that higher prioritization of convenience when food shopping was associated with lower healthy food intake. However, the relationship between food environment measures and diet is strongly modified by consumer behavior. For convenience-prioritizing households, the nearest market proved most associated with healthy diet outcomes. For households with a food-driven purchasing strategy, the preferred market was most associated with healthy diet outcomes. These findings show that market inventory can be healthful or deleterious to diets, depending on how individuals navigate their food environments. Empirical measures of food access that neglect to consider consumer behavior may fail to capture realistic representations of food environment and diet relationships. These findings underscore the importance of tailoring food system changes to incorporate context-specific consumer behavior.

Exploring the Cross-Sectional Relationship Between Implementation Supports for Adopting Nutrition Standards and the Nutritional Quality of School Lunches Served

BackgroundThe evidence-based nutrition standards of the Healthy, Hunger-Free Kids Act of 2010 significantly improved school meal nutrition, yet little is known about how school food authorities (SFAs) were supported to translate the standards into practice in schools. ObjectiveThis study tested whether or not 2 implementation supports, SFA receipt of training/technical assistance (TA) and purchase of new equipment, for implementing the nutrition standards were associated with the nutritional quality of school lunches. DesignThis study used a cross-sectional design. Participants/settingThe study sample included 365 SFAs derived from the US Department of Agriculture’s School Nutrition and Meal Cost Study (2014 to 2015 school year), the only national data of school nutrition environments since the Healthy, Hunger-Free Kids Act of 2010. Main outcome measuresImplementation supports included reported participation in training/TA and the purchase of new equipment between the 2012 to 2013 (year of policy adoption) and 2014 to 2015 school years. The primary outcome, nutritional quality of school lunches served, was defined as low/high Healthy Eating Index 2010 scores during the 2014 to 2015 school year. Secondary implementation supports included the number of areas covered by training/TA, the adequacy of training/TA, and the degree of implementation challenges. Statistical analysesMultivariable-adjusted logistic regression models assessed if receipt of implementation supports was associated with lunch Healthy Eating Index 2010 scores. ResultsThe median lunch Healthy Eating Index 2010 score was 81.7 (95% CI 80.4 to 82.9). Most SFAs (78.4%, 95% CI 72.0% to 85.0%) reported having participated in training/TA and one-third (33.8%, 95% CI 24.4% to 43.2%) reported having purchased new equipment—neither were associated with the odds of having higher Healthy Eating Index 2010 scores for lunches served at the time of data collection. ConclusionsMany SFAs accessed implementation supports to adopt the nutrition standards. Information on dose, quality, and nutrition-related impact of implementation supports using measures of change are needed to determine how best to support SFAs with implementation of new nutrition standards.

Transmission Channel of Agriculture Food Import Tariff to Stunting Prevalence

Increases in food prices affect poverty in a way that poor consumer is harmed due to the high proportion of their budget they spent on food. Stunting prevalence might be instigated by several factors such as access to food and nutrition intake, genetic and environment. This research aims to analyse the effect of food import tariffs towards the stunting prevalence of children aged under 5 (five) across districts in Indonesia, and we explore the indirect relationship between stunting prevalence and trade policy. This research uses quantitative descriptive research methods, utilizing both primary and secondary data. Primary data were obtained through the distribution of questionnaires, followed by Focus Group. Secondary data were obtained from relevant institutions such as the Central Statistics Agency, research journals, and related books. The method of data analysis in the study uses quantitative analysis with a mathematical model. The results showed that tariffs can reduce the consumption of foods that serve in the intake of dietary nutrients such as calories, protein and fat. As a result, food intake affects the prevalence of stunting. Trade liberalisation can have a beneficial impact on child health. The effects of trade liberalisation on stunting through the food channel include: a) trade has a significant effect on calorie, protein, and fat intake, b) intake of these nutrients has a significant effect on child stunting.

Nutritional Epigenomics: Bioactive Dietary Compounds in the Epigenetic Regulation of Osteoarthritis.

Nutritional epigenomics is exceptionally important because it describes the complex interactions among food compounds and epigenome modifications. Phytonutrients or bioactive compounds, which are secondary metabolites of plants, can protect against osteoarthritis by suppressing the expression of inflammatory and catabolic mediators, modulating epigenetic changes in DNA methylation, and the histone or chromatin remodelling of key inflammatory genes and noncoding RNAs. The combination of natural epigenetic modulators is crucial because of their additive and synergistic effects, safety and therapeutic efficacy, and lower adverse effects than conventional pharmacology in the treatment of osteoarthritis. In this review, we have summarized the chondroprotective properties of bioactive compounds used for the management, treatment, or prevention of osteoarthritis in both human and animal studies. However, further research is needed into bioactive compounds used as epigenetic modulators in osteoarthritis, in order to determine their potential value for future clinical applications in osteoarthritic patients as well as their relation with the genomic and nutritional environment, in order to personalize food and nutrition together with disease prevention.

Skin derived branched‐chain fatty acids in fetal horse gut

AbstractBranched‐chain fatty acids (BCFAs) are mostly saturated fatty acids with a methyl branch at the penultimate or antepenultimate position to the CH3 end. Very‐long‐chain BCFAs (C ≥ 20) are uniquely found in surface lipids. Human and California sea lion (Zalophus californianus) are the only two species that possess vernix at birth, and vernix particles carry loads of BCFA to the gut, potentially influencing the establishment of the first microbiota. Horse (Equus caballus) contains high levels of BCFA in its surface lipids, and the current study aims to investigate if BCFA are components of a neonatal foal's gut. Electron ionization tandem mass spectrometry was used to distinguish iso‐ and anteiso‐form of BCFA from straight‐chain fatty acids. Abundant very‐long‐chain iso‐BCFA, mainly even‐numbered iso‐20:0, iso‐22:0, iso‐24:0, and iso‐26:0 were found in horse meconium but not in their manure collected a few months later. There are little differences in BCFA types and concentrations between foal manure and adult manure. Moderate to high levels of very‐long‐chain anteiso‐BCFA were also found. Comparisons of horse meconium BCFA to horse skin cholesterol ester BCFA content and to meconium from human and sea lion suggest its skin derived origin. The study expands our knowledge on the gut nutritional environment of a newborn horse, and further study is needed to establish the relationship between gut BCFA and microbiota composition in the first few hours of life.Practical Applications: Branched‐chain fatty acids (BCFA) are bioactive compounds found in vernix caseosa, the lipid‐laden material covering the surface of a newborn baby. BCFA also reaches high concentrations from the third trimester of gestation until birth. However, the exact functionality and mechanisms of BCFA in the surface and gut of a fetus remain unclear. The current study aims to clarify the lipid conditions in the gut of newborn foals and to identify the associations between BCFA in the gut and on the skin at a critical point when the horse's microbiota establishes itself. The findings of the current study lay a path for studying the physiological functions of BCFA in horse models, potentially accelerating research related to BCFA.

Nutritional Benefits of Millets in Early Childhood: A Review

This study investigates the nutritional benefits of including millets in children’s meals. Millets, a class of small-seeded grains, has drawn interest due to their abundant nutrient content, rich in essential vitamins, minerals and dietary fibers. The major types of millets are, finger millet, pearl millet, Foxtail millet, Porso or white millet. They have become nutritional powerhouses due to their high quantities of phytochemicals and micronutrients which strengthens the body’s immune system. Millets provide high energy and nourishment required in the early stages of child development over other cereals. The major concern of low bioavailability of minerals like iron, calcium and zinc in common cereal-based foods such as rice and wheat, can be fulfilled by millets. The body of research summarizes on how eating millet affects young children’s growth, cognitive development and general health. Through a systematic examination of studies undertaken in varied settings, this review elaborates the contribution of millets in treating nutritional inadequacies and supporting optimal well-being in this vital stage of early childhood. The review aims to provide practical insights for mothers and caregivers, to enhance the nutritional quality of diets for children. The results highlight millet’s potential as a beneficial dietary element and information for improvising young children’s nutritional environment.

Effects of early age of menarche on the health of Indian middle-aged women: A survey study

The age of menarche, which is a sign that a female has reached reproductive maturity, has a significant impact on the health of women. Numerous components, including nutritional status, socioeconomic status, diet, environment, sibling relationship, hereditary and genetic factors, religious group, ethnicity, psychological stress, migration, and chronic illness, have been postulated to influence the age of menarche. Opinions on these theories have varied, both for and against the theory. In a survey it was reported that women complaints joint pains /stiff shoulder and LBA. Risk of musculoskeletal problems and the perception of pain could increase with obesity.To find the prevalence of physiological and psychological health problems in middle-aged females due to early menarche.Women matching the study criteria and willing to participate in the survey were approached and informed consent was taken. An interview was conducted on either a physical or virtual mode by a trained therapist as per the check list designed for this study.The content of the checklist was validated with the help of experts in this study domain and subjected to statistical tests which yielded a Cronbach’s score of 0.967. The participants response on this checklist was analyzed and a strong association of physical and psychological health issue was documented particularly among working women, multiparous women, and with type of delivery women had undergone during 1 pregnancy.The present study documented significant findings with the early age of menarche and its association with physical and psychological health of the women.

Nutrition environments in early childhood education: do they align with best practice? - ERRATUM.

Nutrition environments in early childhood education: do they align with best practice? - ERRATUM.

FGF21 mediating the Sex-dependent Response to Dietary Macronutrients.

Sex is key variable influencing body composition and substrate utilization. At rest, females maintain greater adiposity than males and resist the mobilization of fat. Males maintain greater lean muscle mass and mobilize fat readily. Determining the mechanisms that direct these sex-dependent effects is important for both reproductive and metabolic health. Here, we highlight the fundamental importance of sex in shaping metabolic physiology and assess growing evidence that the hepatokine fibroblast growth factor-21 (FGF21) plays a mechanistic role to facilitate sex-dependent responses to a changing nutritional environment. First, we examine the importance of sex in modulating body composition and substrate utilization. We summarize new data that point toward sex-biased effects of pharmacologic FGF21 administration on these endpoints. When energy is not limited, metabolic responses to FGF21 mirror broader sex differences; FGF21-treated males conserve lean mass at the expense of increased lipid catabolism, whereas FGF21-treated females conserve fat mass at the expense of reduced lean mass. Next, we examine the importance of sex in modulating the endogenous secretion of FGF21 in response to changing macronutrient and energy availability. During the resting state when energy is not limited, macronutrient imbalance increases the secretion of FGF21 more so in males than females. When energy is limited, the effect of sex on both the secretion of FGF21 and its metabolic actions may be reversed. Altogether, we argue that a growing literature supports FGF21 as a plausible mechanism contributing to the sex-dependent mobilization vs preservation of lipid storage and highlight the need for further research.

School health and nutrition environments: A multicountry survey in five countries of sub-Saharan Africa region-Burkina Faso, Ethiopia, South Africa, Sudan, and Tanzania.

Schools are increasingly regarded as a key setting for promoting the health, well-being, and development of children and adolescents. In this multicountry cross-sectional survey, we describe the health, nutrition, and food environments of public primary schools in five urban settings in Africa region: Ouagadougou, Burkina Faso; Addis Ababa, Ethiopia; Durban; South Africa, Khartoum, Sudan; and, Dar es Salaam, Tanzania. We evaluated the school health and nutrition (SHN) environments in three main areas: (1) the availability of health-related policies, guidelines, and school curricula, (2) the provision of health, nutrition, and water, sanitation, and hygiene (WASH)services in schools, and (3) the school food environments and eating habits of adolescents. We used stratified random sampling to recruit 79 schools from five countries. Trained fieldworkers collected standardized questionnaire data from 79 school administrators, 765 food vendors, and 4999 in-school adolescents aged 10-15 years. In our study, 24 out of 79 school administrators were aware of their school's health-related policies and guidelines while 30 schools had a specific SHN curriculum. In general, health, nutrition, and WASH services were inadequate. Possibly due to a lack of school kitchens, 14.4% of students bought snacks and unhealthy foods from food vendors. Our study indicates that schools' food and nutrition environments are insufficient to improve adolescent health and nutrition in the African region, including limited coverage of SHN policies, suboptimal facilities and nutrition services, and unregulated food environments. Schools in sub-Saharan Africa need to improve their health and nutrition environments.

Diverse and multifunctional roles for perlecan (HSPG2) in repair of the intervertebral disc.

Perlecan is a widely distributed, modular, and multifunctional heparan sulfate proteoglycan, which facilitates cellular communication with the extracellular environment to promote tissue development, tissue homeostasis, and optimization of biomechanical tissue functions. Perlecan-mediated osmotic mechanotransduction serves to regulate the metabolic activity of cells in tissues subjected to tension, compression, or shear. Perlecan interacts with a vast array of extracellular matrix (ECM) proteins through which it stabilizes tissues and regulates the proliferation or differentiation of resident cell populations. Here we examine the roles of the HS-proteoglycan perlecan in the normal and destabilized intervertebral disc. The intervertebral disc cell has evolved to survive in a hostile weight bearing, acidic, low oxygen tension, and low nutrition environment, and perlecan provides cytoprotection, shields disc cells from excessive compressive forces, and sequesters a range of growth factors in the disc cell environment where they aid in cellular survival, proliferation, and differentiation. The cells in mechanically destabilized connective tissues attempt to re-establish optimal tissue composition and tissue functional properties by changing the properties of their ECM, in the process of chondroid metaplasia. We explore the possibility that perlecan assists in these cell-mediated tissue remodeling responses by regulating disc cell anabolism. Perlecan's mechano-osmotic transductive property may be of potential therapeutic application.

Impact of Nutrient Enrichment on Community Structure and Co-Occurrence Networks of Coral Symbiotic Microbiota in Duncanopsammia peltata: Zooxanthellae, Bacteria, and Archaea.

Symbiotic microorganisms in reef-building corals, including algae, bacteria, archaea, fungi, and viruses, play critical roles in the adaptation of coral hosts to adverse environmental conditions. However, their adaptation and functional relationships in nutrient-rich environments have yet to be fully explored. This study investigated Duncanopsammia peltata and the surrounding seawater and sediments from protected and non-protected areas in the summer and winter in Dongshan Bay. High-throughput sequencing was used to characterize community changes, co-occurrence patterns, and factors influencing symbiotic coral microorganisms (zooxanthellae, bacteria, and archaea) in different environments. The results showed that nutrient enrichment in the protected and non-protected areas was the greatest in December, followed by the non-protected area in August. In contrast, the August protected area had the lowest nutrient enrichment. Significant differences were found in the composition of the bacterial and archaeal communities in seawater and sediments from different regions. Among the coral symbiotic microorganisms, the main dominant species of zooxanthellae is the C1 subspecies (42.22-56.35%). The dominant phyla of bacteria were Proteobacteria, Cyanobacteria, Firmicutes, and Bacteroidota. Only in the August protected area did a large number (41.98%) of SAR324_cladeMarine_group_B exist. The August protected and non-protected areas and December protected and non-protected areas contained beneficial bacteria as biomarkers. They were Nisaea, Spiroplasma, Endozoicomonas, and Bacillus. No pathogenic bacteria appeared in the protected area in August. The dominant phylum in Archaea was Crenarchaeota. These symbiotic coral microorganisms' relative abundances and compositions vary with environmental changes. The enrichment of dissolved inorganic nitrogen in environmental media is a key factor affecting the composition of coral microbial communities. Co-occurrence analysis showed that nutrient enrichment under anthropogenic disturbances enhanced the interactions between coral symbiotic microorganisms. These findings improve our understanding of the adaptations of coral holobionts to various nutritional environments.

Energetic demands regulate sleep-wake rhythm circuit development

Sleep and feeding patterns lack strong daily rhythms during early life. As diurnal animals mature, feeding is consolidated to the day and sleep to the night. In Drosophila, circadian sleep patterns are initiated with formation of a circuit connecting the central clock to arousal output neurons; emergence of circadian sleep also enables long-term memory (LTM). However, the cues that trigger the development of this clock-arousal circuit are unknown. Here, we identify a role for nutritional status in driving sleep-wake rhythm development in Drosophila larvae. We find that in the 2nd instar larval period (L2), sleep and feeding are spread across the day; these behaviors become organized into daily patterns by the 3rd instar larval stage (L3). Forcing mature (L3) animals to adopt immature (L2) feeding strategies disrupts sleep-wake rhythms and the ability to exhibit LTM. In addition, the development of the clock (DN1a)-arousal (Dh44) circuit itself is influenced by the larval nutritional environment. Finally, we demonstrate that larval arousal Dh44 neurons act through glucose metabolic genes to drive onset of daily sleep-wake rhythms. Together, our data suggest that changes to energetic demands in developing organisms trigger the formation of sleep-circadian circuits and behaviors.

Energetic demands regulate sleep-wake rhythm circuit development.

Sleep and feeding patterns lack strong daily rhythms during early life. As diurnal animals mature, feeding is consolidated to the day and sleep to the night. In Drosophila, circadian sleep patterns are initiated with formation of a circuit connecting the central clock to arousal output neurons; emergence of circadian sleep also enables long-term memory (LTM). However, the cues that trigger the development of this clock-arousal circuit are unknown. Here, we identify a role for nutritional status in driving sleep-wake rhythm development in Drosophila larvae. We find that in the 2nd instar larval period (L2), sleep and feeding are spread across the day; these behaviors become organized into daily patterns by the 3rd instar larval stage (L3). Forcing mature (L3) animals to adopt immature (L2) feeding strategies disrupts sleep-wake rhythms and the ability to exhibit LTM. In addition, the development of the clock (DN1a)-arousal (Dh44) circuit itself is influenced by the larval nutritional environment. Finally, we demonstrate that larval arousal Dh44 neurons act through glucose metabolic genes to drive onset of daily sleep-wake rhythms. Together, our data suggest that changes to energetic demands in developing organisms trigger the formation of sleep-circadian circuits and behaviors.

Thermal plasticity in protective wing pigmentation is modulated by genotype and food availability in an insect model of seasonal polyphenism

Abstract Phenotypic variation in natural populations results from complex interactions between organisms and their changing environments. The environment shapes both phenotypic frequencies (during adaptation) and organismal phenotypes (through phenotypic plasticity). Developmental plasticity, in particular, refers to the phenomenon whereby an organism's phenotype depends on the environmental conditions during development. It can match phenotype to ecological conditions and help organisms to cope with environmental heterogeneity, including differences between alternating seasons. Experimental studies of developmental plasticity often focus on the impact of individual environmental cues and do not take explicit account of genetic variation. In contrast, natural environments are complex, comprising multiple variables with combined effects that are poorly understood and may vary among genotypes. We investigated the effects of multifactorial environments on the development of the seasonally plastic eyespots of Bicyclus anynana butterflies. Eyespot size depends on developmental temperature and is involved in alternative seasonal strategies for predator avoidance. In nature, both temperature and food availability undergo seasonal fluctuations. However, our understanding of how thermal plasticity in eyespot size varies in response to food availability and across genotypes remains limited. To address this, we investigated the combined effects of temperature (T; two levels: 20°C and 27°C) and food availability (N; two levels: control and limited) during development. We examined their impact on wing and eyespot size in adult males and females from multiple genotypes (G; 28 families). We found evidence of thermal and nutritional plasticity and temperature‐by‐nutrition interactions (significant T × N) on the size of eyespots in both sexes. Food limitation resulted in relatively smaller eyespots and tempered the effects of temperature. Additionally, we found differences among families for thermal plasticity (significant G × T effects), but not for nutritional plasticity (non‐significant G × N effects) nor for the combined effects of temperature and food limitation (non‐significant G × T × N effects). Our results reveal the context dependence of thermal plasticity, with the slope of thermal reaction norms varying across genotypes and across nutritional environments. We discuss these results in the light of the ecological significance of pigmentation and the value of considering thermal plasticity in studies of the biological impact of climate change. Read the free Plain Language Summary for this article on the Journal blog.