Development Of Life Stages Research Articles

Why Is It Too Cold? Towards a Mechanistic Understanding of Cold-Water Pollution Effects on Recruitment of an Imperiled Warmwater Fish.

Environmental temperature shapes the ontogeny of ectotherms by influencing rates of growth and development which can be key determinants of survival. Whereas the escalating impacts of water management on freshwater ecosystems is well documented, the effects of cold-water releases from dams-which can alter downstream temperatures-remains relatively underexplored but may present novel challenges to endemic ectotherms. Specifically, little is known about how thermal depressions reshape phenotypic and genetic patterns during larval metamorphosis for fishes that evolved in warmwater systems. We assessed the effects of thermal shifts on larval ontogeny of the endangered razorback sucker (Xyrauchen texanus), which evolved in the warm waters of the Colorado River Basin, USA. We hypothesised that development is more sensitive to cold-water influences than growth and that temperature would influence patterns in gene expression related to development. Our results supported these hypotheses and showed that both wild and laboratory-reared larvae in slightly cooler temperatures exhibited delayed development, but similar growth compared to larvae reared in warmer conditions. These findings suggest growth and development in early ectotherm life stages can be decoupled, which follows patterns more like the temperature-size rule than allometric scaling of development by size. We also observed transcriptional differences related to genes associated with stress responses and development in our laboratory-reared fish; here, gene expression of fish from the coldest conditions at the end of the experiment was more similar to fish reared in warmer temperatures at the midpoint. Our findings suggest that modest temperature reductions can delay ontogeny and alter the transcriptional landscape while not necessarily limiting growth. This finding highlights the need for conservation practitioners to consider cascading impacts that even small temperature reductions can cause in riverine ecosystems.

Predictive Utility of the Multi-Process Action Control Framework for Self-Reported and Device-Measured Physical Activity Behavior of Adolescents.

Understanding the correlates of physical activity behavior is imperative for informing the development of interventions to address the low rates of physical activity guideline adherence among adolescents living in the United States. This cross-sectional study examined the predictive utility of the Multi-Process Action Control (M-PAC) framework for explaining self-reported and device-measured physical activity behavior among a Hispanic-majority sample of adolescents. A total of 1849 high school students (mean age = 16.0 ± 1.22 SD years; 52.3% women; 87.8% Hispanic) enrolled in one school district in south-central Texas completed a survey including instruments to assess M-PAC framework constructs (instrumental and affective attitudes, perceived capability and opportunity, behavioral regulation, habit, identity) and moderate-to-vigorous physical activity (MVPA) behavior. A subsample (n = 435) wore accelerometers for seven days. The results from robust linear regression models revealed role identity and habit were significant predictors of self-reported MVPA. Role identity was a significant predictor of accelerometer-derived daily MVPA and raw acceleration in the most active hour but not daily raw acceleration. The findings indicated reflexive processes are robust predictors of adolescent physical activity and should be the focus of interventions designed to promote adoption and maintenance of physical activity during this developmental life stage.

CC-Connect: Identifying solutions to elevating the cancer experience for adolescents and young adults (AYA) with cancer.

Adolescents and young adults with cancer (AYAs, aged 15 to 39 years) experience unique challenges due to their developmental life stage, and many have limited access to support and resources. CC-Connect, the patient assistance component of the White House Cancer Moonshot CC-DIRECT initiative that aims to help childhood cancer families find the best care for their child, undertook a multipronged effort to identify key strategies for addressing the unique needs of AYAs with cancer. This paper describes the four strategies that emerged to form a comprehensive framework for addressing the unmet needs of AYAs with cancer, which can improve outcomes and enhance the cancer care experience for this vulnerable population.

Financial Distress in Testicular Cancer Survivors and Its Impact on Cancer Survivors’ Quality of Life in the German Healthcare System

Introduction: Testicular cancer accounts for the largest proportion of solid tumors in young adult men. With an average age of onset under 40 years and a relative 5-year survival of 97%, it is one of the prognostically favorable tumors. Little is known about the relationship between the financial burden and physical and emotional health of testicular cancer survivors. We examined the association between financial problems caused by cancer and the self-reported quality of life in a cohort-based sample of testicular cancer patients. Methods: A cross-sectional analysis of testicular cancer patients (n = 87, average age 39 years) was performed. Self-reported data were collected on demographics, income, wealth, cost-coping strategies, out-of-pocket costs, supportive medication compliance, quality of life, and perceived social isolation. A multivariable regression model was used to examine the relationship between the degree to which cancer caused financial burdens and the patientsʼ reported quality of life. Results: The survey showed that, in addition to illness-related additional expenses, a disease-related loss of income can lead to severe financial disadvantages and impair quality of life. The study data show that concerns about the economic situation can increase the burden on patients which already results from cancer diagnosis and therapy. In this patient cohort, 32% reported financial stress. Conclusion: Financial distress affects testicular cancer survivors in unique ways. To provide support, health professionals should consider survivorsʼ developmental life stage to understand their financial stress, and ultimately, to improve quality of life.

Investigating the lipid profile of Anopheles stephensi mosquitoes across developmental life stages

Holometabolous insects undergo a distinct transition in their development, tightly correlated with shifting feeding patterns from larval stages and some adult phases to non-feeding phases as pupae and during other adult phases. Furthermore, the intricate life cycle of mosquitoes involves a sequence of developmental stages influenced by aquatic and terrestrial factors, demanding precise energy resource orchestration. Lipids serve multifaceted roles, encompassing energy storage, membrane structure, and participation in signal transduction and molecular recognition processes. A significant gap in the current research landscape is the need for a comprehensive study exploring the lipid repertoire throughout the developmental stages of Anopheles stephensi mosquitoes. We undertook an analysis of the An. stephensi metabolome across all life stages. We hypothesized that An. stephensi mosquitoes will have unique lipid metabolite markers for each life stage. A specific extraction and LC-MS based lipidomic approach was used to test this hypothesis. Our findings demonstrated that our methods were successful, with lipids comprising 62.15 % of the analyzed metabolome. Additionally, phospholipids (PL), lysophospholipids (LPL), sphingomyelin (SM), and triglycerides (TG) were abundant and dynamic across all life stages. Interestingly, comparison between the L1 and L2 lipidome revealed a dominant pattern of specific TGs in decreased abundance between these two life stages. Lastly, 20-hydroxyecdysone (20E), was found to be present in similar abundance across all 4 larval stages. These data indicate that there may be lipid metabolome pathways serving unique roles during mosquito development that may be used to explore laboratory management of colonies, parasite resistance, and environmental adaptation.

The effects of exposure to and timing of a choline-deficient diet during pregnancy and early postnatal life on the skeletal muscle transcriptome of the offspring

Nonalcoholic fatty liver disease (NAFLD) is related to muscle loss, but the precise mechanism underlying this association remains unclear. The aim of the present study was thus to determine the influence of maternal fatty liver and dietary choline deficiency during pregnancy and/or lactation periods on the skeletal muscle gene expression profile among 24-day-old male rat offspring. Histological examination of skeletal muscle tissue specimens obtained from offspring of dams suffering from fatty liver, provided with proper choline intake during pregnancy and lactation (NN), fed a choline-deficient diet during both periods (DD), deprived of choline only during pregnancy (DN), or only during lactation (ND), was performed. The global transcriptome pattern was assessed using a microarray approach (Affymetrix® Rat Gene 2.1 ST Array Strip). The relative expression of selected genes was validated by real-time PCR (qPCR). Morphological differences in fat accumulation in skeletal muscle related to choline supply were observed. The global gene expression profile was consistent with abnormal morphological changes. Mettl21c gene was overexpressed in all choline-deficient groups compared to the NN group, while two genes, Cdkn1a and S100a4, were downregulated. Processes of protein biosynthesis were upregulated, and processes related to cell proliferation and lipid metabolism were inhibited in DD, DN, and ND groups compared to the NN group. Prenatal and early postnatal exposure to fatty liver and dietary choline deficiency leads to changes in the transcriptome profile in skeletal muscle of 24-day old male rat offspring and is associated with muscle damage, but the mechanism of it seems to be different at different developmental stages of life. Adequate choline intake during pregnancy and lactation can prevent severe muscle disturbance in the progeny of females suffering from fatty liver.

Human Milk Oligosaccharides: Potential Upshot on Health at Early Life Stage Development

In the crucial early months of life, an infant's health, growth, and safeguarding are paramount. Breastfeeding stands out as the optimal and natural means of nourishment, offering profound benefits for their development and overall wellness. Within breast milk, a rich array of bioactive components, including hormones, oligosaccharides, and immunoglobulins, provide neonates with an ideal nutritional balance. Among these, Human Milk Oligosaccharides (HMOs) rank prominently, serving both as prebiotics and shields against various neonatal ailments. Particularly, compounds like 2′-Fucosyllactose (2′-FL) and Lacto-N-Neotetraose (LNnT) have been deemed safe for integration into infant formulas, amplifying their benefits. Extensive research underscores the manifold advantages of HMOs, from modulating gut microbiota to bolstering immune function and thwarting pathogenic invaders. HMOs also exhibit a nuanced interplay with maternal genetics, influencing their quantity and diversity. Infants nursed by secretor mothers tend to enjoy enhanced HMO benefits compared to non-secretor counterparts. Incorporating HMOs like Lacto-N-Neotetraose and 2′-Fucosyllactose into infant formulas represents a pivotal stride in optimizing child nutrition. This review offers a thorough exploration of recent research on HMOs, delving into their varied types, concentrations, and compositions, while emphasizing their profound impact on infant health and safety. By consolidating current research findings and recent progress, this study seeks to clarify the diverse effects of HMOs on different facets of human physiology, immune system maturation, modulation of gut microbiota, neurological functioning, and lifelong health implications. Emphasizing the pivotal role of HMOs in influencing human well-being from infancy to maturity, this review emphasize the necessity for continued research and potential utilization in clinical settings and nutritional science.

Bone-nerve crosstalk: a new state for neuralizing bone tissue engineering-A mini review.

Neuro bone tissue engineering is a multidisciplinary field that combines both principles of neurobiology and bone tissue engineering to develop innovative strategies for repairing and regenerating injured bone tissues. Despite the fact that regeneration and development are considered two distinct biological processes, yet regeneration can be considered the reactivation of development in later life stages to restore missing tissues. It is noteworthy that the regeneration capabilities are distinct and vary from one organism to another (teleost fishes, hydra, humans), or even in the same organism can vary dependent on the injured tissue itself (Human central nervous system vs. peripheral nervous system). The skeletal tissue is highly innervated, peripheral nervous system plays a role in conveying the signals and connecting the central nervous system with the peripheral organs, moreover it has been shown that they play an important role in tissue regeneration. Their regeneration role is conveyed by the different cells' resident in it and in its endoneurium (fibroblasts, microphages, vasculature associated cells, and Schwann cells) these cells secrete various growth factors (NGF, BDNF, GDNF, NT-3, and bFGF) that contribute to the regenerative phenotype. The peripheral nervous system and central nervous system synchronize together in regulating bone homeostasis and regeneration through neurogenic factors and neural circuits. Receptors of important central nervous system peptides such as Serotonin, Leptin, Semaphorins, and BDNF are expressed in bone tissue playing a role in bone homeostasis, metabolism and regeneration. This review will highlight the crosstalk between peripheral nerves and bone in the developmental stages as well as in regeneration and different neuro-bone tissue engineering strategies for repairing severe bone injuries.

Redesign of a Life Cycle Figure Improves Student Conceptions of Ecology and Evolution

Life cycle diagrams communicate the developmental life stages of an organism. Design choices may inadvertently communicate additional information about survivorship rates, genetic variation, and microevolutionary change. In this controlled experiment, we randomly assigned one of three life cycle diagrams to 684 college students. Each figure included identical life stages of a fictitious organism’s development but differed in (1) the number of offspring (single or multiple) and (2) layout (cyclical or linear). Each participant could reference the figure when answering questions about organism survival, variation among offspring, and variation between generations. Students scored 28–30% higher on questions about survivorship when the available diagram included multiple offspring. Students scored 19–30% higher on questions about microevolution when the diagram layout was linear. Overall, students who received the figure with a linear layout and multiple offspring earned the highest average score (54.5%, or 3.3 of six questions) on the assessment, while students with the traditional figure (cyclical layout with single offspring) scored the lowest average (26.1%, or 1.6 of six questions). These results suggest that figure design affects student interpretations and may assist student learning about ecology and evolution concepts and common misconceptions.

Childcare centre soil microbiomes are influenced by substrate type and surrounding vegetation condition

Urban development has profoundly reduced human exposure to biodiverse environments, which is linked to a rise in human disease. The ‘biodiversity hypothesis’ proposes that contact with diverse microbial communities (microbiota) benefits human health, as exposure to microbial diversity promotes immune training and regulates immune function. Soils and sandpits in urban childcare centres may provide exposure to diverse microbiota that support immunoregulation at a critical developmental stage in a child's life. However, the influence of outdoor substrate (i.e., sand vs. soil) and surrounding vegetation on these environmental microbiota in urban childcare centres remains poorly understood. Here, we used 16S rRNA amplicon sequencing to examine the variation in bacterial communities in sandpits and soils across 22 childcare centres in Adelaide, Australia, plus the impact of plant species richness and habitat condition on these bacterial communities. We show that sandpits had distinct bacterial communities and lower alpha diversity than soils. In addition, we found that plant species richness in the centres' yards and habitat condition surrounding the centres influenced the bacterial communities in soils but not sandpits. These results demonstrate that the diversity and composition of childcare centre sandpit and soil bacterial communities are shaped by substrate type, and that the soils are also shaped by the vegetation within and surrounding the centres. Accordingly, there is potential to modulate the exposure of children to health-associated bacterial communities by managing substrates and vegetation in and around childcare centres.

Salivary Calprotectin Levels and Bone Mineral Density in Post-Menopausal Women With and Without Chronic Periodontitis - An Evaluative Study.

Menopause is a normal developmental stage in a woman's life marking the permanent cessation of menstruation. Periodontitis and osteoporosis are noteworthy health concerns in post-menopausal women. Calprotectin is an inflammatory biomarker for precise diagnosis of periodontal disease. This study was performed to evaluate the variations in salivary calprotectin levels and bone mineral density in post-menopausal women with and without chronic periodontitis. The study included 24 post-menopausal women aged 45-57 years and was divided into group 1 (12 post-menopausal women without chronic periodontitis) and group 2 (12 post-menopausal women with chronic periodontitis). Unstimulated salivary samples, panoramic radiographs and clinical examination were performed. The collected samples were combined with CALPRO antibody with horseradish peroxide (HRP) that results in the formation of antigen-antibody complex. Tetramethylbenzidine (TMB) solution was added that turned blue. Colour change was measured at 450nm. A human ELISA kit was used. Data collected were sent for statistical analysis. There was a statistically significant difference in salivary calprotectin levels between groups 1 and 2 ( P = 0.016) and no statistical difference in mean bone mineral density levels between the two groups ( P = 0.235). A positive correlation was seen between salivary calprotectin levels and bone mineral density in group 2 ( P = 0.013).

Developmental Shifts in the Microbiome of a Cosmopolitan Pest: Unraveling the Role of Wolbachia and Dominant Bacteria.

Wolbachia bacteria (phylum Proteobacteria) are ubiquitous intracellular parasites of diverse invertebrates. In insects, coevolution has forged mutualistic associations with Wolbachia species, influencing reproduction, immunity, development, pathogen resistance, and overall fitness. However, the impact of Wolbachia on other microbial associates within the insect microbiome, which are crucial for host fitness, remains less explored. The diamondback moth (Plutella xylostella), a major pest of cruciferous vegetables worldwide, harbors the dominant Wolbachia strain plutWB1, known to distort its sex ratio. This study investigated the bacterial community diversity and dynamics across different developmental life stages and Wolbachia infection states in P. xylostella using high-throughput 16S rDNA amplicon sequencing. Proteobacteria and Firmicutes dominated the P. xylostella microbiome regardless of life stage or Wolbachia infection. However, the relative abundance of dominant genera, including an unclassified genus of Enterobacteriaceae, Wolbachia, Carnobacterium, and Delftia tsuruhatensis, displayed significant stage-specific variations. While significant differences in bacterial diversity and composition were observed across life stages, Wolbachia infection had no substantial impact on overall diversity. Nonetheless, relative abundances of specific genera differed between infection states. Notably, Wolbachia exhibited a stable, high relative abundance across all stages and negatively correlated with an unclassified genus of Enterobacteriaceae, Delftia tsuruhatensis, and Carnobacterium. Our findings provide a foundational understanding of the complex interplay between the host, Wolbachia, and the associated microbiome in P. xylostella, paving the way for a deeper understanding of their complex interactions and potential implications for pest control strategies.

Effects of water temperature changes on the early life stages (egg and larvae) of walleye Pollock (Gadus chalcogrammus) – Laboratory experiments and field applications

The eastern coast of Korea (ECK) is the southern limit of walleye pollock (pollock) distribution in the North Pacific. Since the climate regime shift in the 1980s, pollock catch has decreased sharply, with <1 ton recorded annually since the 2000s. Pollock, a semi-demersal cold-water species, is greatly affected by sea surface temperature changes during its early life stages. This study analyzed the effect of different water temperatures (3.6, 5.1, 7.1, 10.0, 13.3, and 15.1 °C) on the survival and growth of fertilized pollock eggs and larvae to investigate whether the ECK is still suitable for the early life stages development of pollock. The hatching rate of eggs was 82%, 57%, and 4%, and the hatching period was 20.7, 11.6, and 5.6 d at 3.6, 10.0, and 15.1 °C, respectively. The larval size-at-hatch was the highest at 3.6 °C (5.14 mm) and lowest at 15.1 °C (4.24 mm). Above 10.0 °C, the hatching rate decreased rapidly, and the abnormality rate increased. Since the 1980s, the 10 °C isotherm in the ECK has been moving northward in winter, which is the pollock spawning season. Continuous warming of the ECK has thus been unfavorable for the early life stages of pollock. Overall, this study improves our understanding of changes in pollock abundance due to climate change.

Barriers Perceived by Pre-Engineering Students at FSc. Level and its Impact on Academic Satisfaction

Adolescence is the most crucial developmental and emotional stage of life where educational decision-making takes center stage. This challenge is especially difficult for the students of pre-engineering. The highest attrition rate is prevalent in STEM due to a lack of interest and academic dissatisfaction among students which is in part due to a number of barriers perceived by them. Therefore, the major objectives for this research were to identify those perceived barriers, develop an indigenous valid and reliable measure for identifying perceived barriers in pursuing pre-engineering, quantify the most encountered barrier, and establish the impact of perceived barriers on academic satisfaction. The present research was accomplished in two phases. In Phase I, a 27-item Perceived Barriers in Pursuing Pre-Engineering Scale was developed by utilizing an empirical approach. Through principle component analysis of exploratory factor analysis (N = 324), 4 factors emerged, and another iteration gave 3 factors. However, a unidimensional scale was finalized following the consensus of Subject Matter Experts to maintain the theoretical integrity. In Phase II (N = 923), adequate psychometric properties of the measure were established. The most commonly reported barrier turned out to be pressure from the family on subject selection. A significantly negative relationship was found between perceived barriers and academic satisfaction. Male students reported higher scores on barriers and academic satisfaction than female students. This research has important implications for stakeholders seeking to rectify low enrollment rates in engineering.

Exploring Maternal and Child Health Among Tribal Communities in India: A Life Course Perspective.

India experiences high rates of maternal and infant mortality and morbidity, with tribal communities disproportionately affected. Tribal populations frequently live in unfavorable socio-economic conditions and deficient social health indicators, culminating in adverse health consequences. Using a life course perspective, this qualitative study explored risks over the life course that contribute to maternal and child health problems among tribal populations in India. Additionally, the study examined barriers to utilization of healthcare services during the pregnancy and postpartum periods. Data collection occurred between 2017 and 2019 through participant observation, key informant interviews (n = 7) and in-depth interviews (n = 68) and a focus group (n = 7) with tribal women from the Madia-Gond tribe in the Indian state of Maharashtra. Additionally, verbal autopsies were conducted with relatives of three deceased women and five infants from the tribe. Multiple risk factors operating at different socio-ecological levels and developmental stages of life were associated with maternal and child health problems among the tribe. These included adherence to traditional harmful practices, limited access to nutritional diet, women's health neglected due to the double burden of domestic and professional labor, and a lack of accessible and well-equipped medical facilities. Inaccesibility stemmed from factors including extreme poverty, geographical isolation, and suboptimal healthcare infrastructure. There is need for provisions to promote access to care and to promote education and awareness centered on evidence-supported healthcare, particularly targeted towards expectant mothers. The implementation of nutritional support programs may help mitigate high maternal and child mortality and morbidity rates prevalent among tribal populations.

Trends of risk factors associated with childhood stunting and anaemia in Ghana: evidence from the Demographic Health Survey and Multiple Indicator Cluster Survey (2003-2017).

This study investigated the trend of effect estimates of the key risk factors of childhood stunting and anaemia between 2003 and 2017. A secondary analysis of the Demographic Health Survey (DHS) and Multiple Indicator Cluster Survey (MICS) data for the Ghanaian population between 2003 and 2017. Associations of selected socio-demographic (child age and gender; maternal age and education), economic (household wealth), environmental, dietary (minimum dietary diversity and iodine use) and health system (place of delivery and vaccination) factors were explored using the Poisson regression model. Trend analysis was explored using a fitted linear regression line on a time series plot. Ghana. Children under 5 years. The results showed a reduction in the prevalence of stunting and anaemia over the 15-year duration. These health outcomes were found to be negatively associated with a wide array of socio-demographic (child age and gender, maternal age and education, residency), economic (household wealth), dietary (iodised salt use) and health service (place of delivery and vaccination) factors; however, the most consistent statistically significant association was observed between child's age and belonging to the poor wealth quintile. In order to prevent these indicators of child malnutrition, key consideration must be given to the early developmental stages of life. Child health policies must focus on addressing the key contextual factors of child malnutrition.

Neurodevelopment effects of early life bisphenol-A exposure on visual memory: Insights into recovery dynamics

Bisphenol A (BPA), a ubiquitous endocrine disruptor, is implicated in the cognitive deficits observed in both children and animals. Especially, BPA-induced spatial memory deterioration during the whole development phase of rodents has been well delineated. However, whether BPA exposure on the different development phases exerts similar effects on the prefrontal cortex (PFC) dependent visual memory is still elusive. Here, we chose two exposure windows, the whole gestation and lactation phases (E0∼P21) and the whole juvenile and adolescent phases (P22∼P60), for exposing rats to BPA. The visual memory of those rats was accessed by object recognition testing in the open field after BPA exposure and a constant recovery interval. The results revealed a substantial decline of visual memory under both exposure conditions, accompanied by an increase in anxiety-like behavior in BPA-exposed rats. Notably, after a 20-day recovery period, those behavioral changes induced by BPA exposure during P22∼60, not E0∼P21, were reversed compared to the control rats. According to morphological analysis of those rats after recovery, we found that the spine density of pyramidal neurons in the PFC were significant decreased in rats with BPA exposure during E0∼P21 and there was no difference between rats with or without BPA exposure during P22∼P60. Additionally, a similar change trend in excitatory receptors expression was observed under both exposure conditions. After an additional 20 days of recovery, the behavioral changes in rats with perinatal BPA exposure reverted to the normal status. Our present findings illuminate the dynamic effects of BPA on PFC-dependent functions across two crucial early developmental stages of life.

Testing biological actions of medicinal plants from northern Vietnam on zebrafish embryos and larvae: Developmental, behavioral, and putative therapeutical effects.

Evaluating the risks and benefits of using traditional medicinal plants is of utmost importance for a huge fraction of the human population, in particular in Northern Vietnam. Zebrafish are increasingly used as a simple vertebrate model for testing toxic and physiological effects of compounds, especially on development. Here, we tested 12 ethanolic extracts from popular medicinal plants collected in northern Vietnam for their effects on zebrafish survival and development during the first 4 days after fertilization. We characterized more in detail their effects on epiboly, hatching, growth, necrosis, body curvature, angiogenesis, skeletal development and mostly increased movement behavior. Finally, we confirm the effect on epiboly caused by the Mahonia bealei extract by staining the actin filaments and performing whole genome gene expression analysis. Further, we show that this extract also inhibits cell migration of mouse embryo fibroblasts. Finally, we analyzed the chemical composition of the Mahonia bealei extract and test the effects of its major components. In conclusion, we show that traditional medicinal plant extracts are able to affect zebrafish early life stage development to various degrees. In addition, we show that an extract causing delay in epiboly also inhibits mammalian cell migration, suggesting that this effect may serve as a preliminary test for identifying extracts that inhibit cancer metastasis.

Effects of mine tailing exposure on the development of early life stages of the marine copepod Calanus finmarchicus

ABSTRACT The demand for mineral resources is increasing mining activities worldwide. In Norway, marine tailing disposal (MTD) is practiced, introducing mineral particles into fjord ecosystems. We investigated the effects of two concentrations (high and low) of fine tailings from a CaCO3 processing plant on early life stages of the marine copepod Calanus finmarchicus. Results show that the exposure did not significantly impact hatching success or development in non- and early feeding life stages. However, feeding stage nauplii ingested tailings, which caused a significantly slower development in later nauplii stages in high exposure groups, with most individuals being two stages behind the control group. Further, high mortality occurred in late nauplii and early copepodite stages in low exposure groups, which could be caused by insufficient energy accumulation and depleted energy reserves during development. Individuals exposed to high exposure concentrations seemed to survive by arresting development and potentially by reduced activity, thereby conserving energy reserves. In nature, slower development could affect lipid storage buildup and reproduction.

Unveiling the early life core microbiome of the sea cucumber Apostichopus japonicus and the unexpected abundance of the growth-promoting Sulfitobacter

BackgroundMicrobiome in early life has long-term effects on the host’s immunological and physiological development and its disturbance is known to trigger various diseases in host Deuterostome animals. The sea cucumber Apostichopus japonicus is one of the most valuable marine Deuterostome invertebrates in Asia and a model animal in regeneration studies. To understand factors that impact on host development and holobiont maintenance, host-microbiome association has been actively studied in the last decade. However, we currently lack knowledge of early life core microbiome during its ontogenesis and how it benefits the host’s growth.ResultsWe analyzed the microbial community in 28 sea cucumber samples from a laboratory breeding system, designed to replicate aquaculture environments, across six developmental stages (fertilized eggs to the juvenile stage) over a three years-period to examine the microbiomes’ dynamics and stability. Microbiome shifts occurred during sea cucumber larval ontogenesis in every case. Application of the most sophisticated core microbiome extraction methodology, a hybrid approach with abundance-occupancy core microbiome analyses (top 75% of total reads and > 70% occupation) and core index calculation, first revealed early life core microbiome consisted of Alteromonadaceae and Rhodobacteraceae, as well as a stage core microbiome consisting of pioneer core microbe Pseudoalteromonadaceae in A. japonicus, suggesting a stepwise establishment of microbiome related to ontogenesis and feeding behavior in A. japonicus. More interestingly, four ASVs affiliated to Alteromonadaceae and Rhodobacteraceae were extracted as early life core microbiome. One of the ASV (ASV0007) was affiliated to the Sulfitobactor strain BL28 (Rhodobacteraceae), isolated from blastula larvae in the 2019 raring batch. Unexpectedly, a bioassay revealed the BL28 strain retains a host growth-promoting ability. Further meta-pangenomics approach revealed the BL28 genome reads were abundant in the metagenomic sequence pool, in particular, in that of post-gut development in early life stages of A. japonicus.ConclusionRepeated rearing efforts of A. japonicus using laboratory aquaculture replicating aquaculture environments and hybrid core microbiome extraction approach first revealed particular ASVs affiliated to Alteromonadaceae and Rhodobacteraceae as the A. japonicus early life core microbiome. Further bioassay revealed the growth promoting ability to the host sea cucumber in one of the core microbes, the Sulfitobactor strain BL28 identified as ASV0007. Genome reads of the BL28 were abundant in post-gut development of A. japonicus, which makes us consider effective probiotic uses of those core microbiome for sea cucumber resource production and conservation. The study also emphasizes the importance of the core microbiome in influencing early life stages in marine invertebrates. Understanding these dynamics could offer pathways to improve growth, immunity, and disease resistance in marine invertebrates.