SEARCH · Search PubMed

Results for “Infant Development”

Search indexed PubMed citations on genomics, clinical trials, systematic reviews and public health. Explore titles, authors and supplied subject terms, then open the PubMed record.

SourceResearch connectionFrom yearThrough year

Quote a phrase for an exact phrase match. Source license links do not imply unrestricted reuse.

622 records · Page 11Linked to original sources

PubMed2026

Investing in Canada's nursing workforce: a comprehensive review to inform policy innovations and directions.

BACKGROUND: Health systems worldwide face persistent health workers challenges including nursing shortages, workforce strain, and inequities. In Canada, these challenges have prompted renewed national and provincial reforms to strengthen recruitment, retention, leadership, and sustainability. This paper compares nursing workforce policy directions across Canada, and international jurisdictions to inform policy and planning. METHODS: A cross-country comparative analysis of policies building on a comprehensive national funded review that included an umbrella review of 69 systematic reviews, a comparative policy review of nursing workforce strategies in five jurisdictions, and validation through national horizon-scanning and policy dialogues (n >100). Evidence was analyzed across system, organizational, and individual levels. RESULTS: At the system level, international jurisdictions demonstrate comprehensive, legislated approaches integrating data, governance, and multi-year funding have advanced key nursing strategies. In Canada, the advances show the importance of strategies to have national and provincial/territorial alignment emphasizing leadership, flexibility, and inclusion as key levers. Organizational and individual-level reforms such as mentorship, leadership development, and wellness initiatives are expanding but remain variably evaluated. Experts identified national workforce data strategies and policy integration with embedded evaluation as key enablers to inform scalability and sustainability of implemented strategies. CONCLUSIONS: Canada's nursing workforce reforms are advancing toward coordinated, equity-driven, and evidence-informed strategies. Continued investment in evaluation, leadership, and national integrated data systems along with integrating nursing workforce planning within broader intersectoral planning will consolidate these gains and position Canada as an international leader in sustainable nursing workforce policy.

Canada↗

PubMed2026

Epigenetic drift and LINE-1 activation in aging brain: Implications for neurodegenerative disease.

Brain aging and age-associated neurological diseases, such as Alzheimer's Disease (AD), Parkinson's Disease (PD), and Amyotrophic Lateral Sclerosis (ALS), are largely attributed to epigenetic drift which is characterized by the gradual accumulation of alterations in neural cell methylation patterns over time. These methylation changes are particularly evident in transposable element (TE)-derived sequences such as Long interspersed element-1 (LINE-1) which comprises approximately 17% of the human genome. During aging, LINE-1 elements gradually lose their methylation, as well as the regulatory safeguard mechanisms that usually keep them inactive. This repression loss can lead to LINE-1 reactivation, contributing to harmful effects including genomic instability, neuroinflammation, and more. Together these findings indicate that impaired epigenetic maintenance, especially in repetitive genome regions, plays a key role in biological aging of neurons and glial cells. In this narrative review, we discuss the methylation dynamics and regulatory mechanisms of LINE-1 retrotransposons, their activation processes during aging, and contribution to age-associated neurological diseases. We also highlight the potential of targeting LINE-1 methylation to restore methylation homeostasis, epigenetic stability and delay brain aging.

Humans↗

PubMed2026

Six weeks of isometric resistance training led to evidence of corticospinal but not reticulospinal adaptation in previously untrained adult males.

The latest hypothesis regarding the source of enhanced neural activation from resistance training is the reticulospinal rather than the corticospinal tract, based on invasive animal and emerging human data. The present study employed a six-week isometric resistance training intervention in a randomized controlled design to address this knowledge gap. Thirty-nine healthy, untrained males (age ~23 y, sustained contraction group n = 13, explosive contraction group n = 9, control group n = 17) underwent neuromuscular and electrophysiological testing and completed all study requirements. Maximal isometric torque (MVC) and rate of torque development (RTD) were measured during a familiarization session as well as before and after the six-week period. Transcranial magnetic stimulation was used to assess motor-evoked potential (MEP) area and silent period duration while subjects contracted to 10% of MVC. Loud sound (120 dB) was used to modulate MEP area and reaction time to visual stimuli during the StartReact test. Only the intervention groups demonstrated significant improvements in MVC (27%) and RTD (60%) (both P < 0.01), along with reduced MEP area (- 21%) and silent period duration (- 23%) (both P < 0.01). The sustained contraction group showed reduced modulation of reaction time and increased MEP suppression due to loud sound. Short-term resistance training seemed to reduce cortical inhibition and corticospinal excitability in both training groups. The study showed conflicting changes in measures purported to evaluate reticulospinal functioning. It is recommended to examine different forms of resistance training and longer training exposure in future.

Humans↗

PubMed2026

To longevity and beyond: A systems view of aging and stress resilience.

Aging is a dynamic and time-dependent process characterized by progressive functional decline across biological systems. Key hallmarks, including genomic instability, telomere attrition, loss of proteostasis, mitochondrial dysfunction, and immunosenescence, have been widely described, each reflecting distinct yet interconnected mechanistic frameworks. Rather than acting in isolation, these processes arise from complex interactions among cellular stressors, impaired repair mechanisms, and the cumulative burden of maladaptive responses. This system-level perspective explains the inter-individual variability in aging trajectories. Centenarians represent an extreme and informative model of successful aging, in which the balance between damage accumulation and repair is shifted toward the maintenance of physiological function. Their exceptional longevity is supported by coordinated genetic, epigenetic, metabolic, and immunological adaptations that enhance resilience to age-related stressors. Here, we summarize the biological drivers and theoretical frameworks of aging within an integrative context, focusing on mechanisms associated with extended healthspan in centenarians. We also examine the contribution of major animal models, highlighting their complementary roles in elucidating conserved and species-specific aging pathways. Overall, aging outcomes reflect a dynamic equilibrium between damage and repair processes. Understanding how this balance is modulated in long-lived individuals may inform strategies to promote healthy aging and delay the onset of age-related diseases.

Humans↗

PubMed2026

Studies on functional differentiation of xpr1a and xpr1b genes in zebrafish.

Xenotropic and polytropic retrovirus receptor 1 (XPR1) is known to be involved in various biological processes, including phosphate homeostasis, cellular signaling, brain and vascular mineralization, whereas its specific contribution to bone development remains incompletely characterized. Due to genome duplication in teleosts, zebrafish Danio rerio possess two paralogous genes of XPR1 namely xpr1a and xpr1b, whose functional divergence remains unclear. The amino acid sequence similarity between zebrafish xpr1a and xpr1b was 83.26%. In situ hybridization demonstrated overlapping localization in the head and spinal cord at 24-48 hpf, while diverged by 72 hpf, with xpr1a becoming restricted to the head while xpr1b persisted in both regions. CRISPR/Cas9 was used to generate xpr1a and xpr1b mutants. The xpr1a mutants are comparatively healthy, viable but with mild growth reduction, whereas the xpr1b mutants display high mortality, reduced body length and severe vertebral deformities. Interestingly, all the double mutants died at the embryonic stage. Moreover, to further investigate the molecular and regulatory mechanisms, we conducted comparative transcriptome analysis on bone and brain tissues from xpr1b+/+ and xpr1b-/- zebrafish. In bone tissue, 6749 DEGs were identified, comprising 3846 upregulated and 2903 downregulated genes. These DEGs were mainly enriched in the MAPK signaling pathway, Wnt signaling pathway, cysteine and methionine metabolism, and ECM-receptor interaction. RT-qPCR validated results showed that seven osteogenesis-related genes (col1a1a, sp7, runx2b, col1a2, col1a1b, alp1 and entpd5), and two phosphate homeostasis related genes (slc20a2 and pdgfba), which are essential for skeletal mineralization and phosphate homeostasis, exhibited significantly downregulated expression in bone tissue of xpr1b mutant zebrafish. These results highlight the pivotal role of xpr1b in regulating skeletal mineralization and phosphate metabolism, thereby elucidating the functional specialization of XPR1 paralogs while providing a theoretical basis for understanding bone developmental mechanism in teleost vertebrates.

Animals↗

PubMed2026

Ensemble DNA methylation clock demonstrates Immune-metabolic aging signatures associated with mortality.

Aging is a multifactorial process that is best described in terms of the progressive acquisition of multiple layers of phenotypic changes, such as epigenetic modifications, inflammation, and metabolic dysregulation. DNA methylation clocks have been extensively used to construct epigenetic clocks based on the DNAm profiles that can be used to estimate biological age and predict age-associated outcomes. Nevertheless, the vast majority of clocks constructed so far have been based on linear models, which are unlikely to fully account for the heterogeneity and non-linearity of survival-related DNAm signatures. In this work, we constructed a heterogeneous stacked ensemble survival model based on DNAm data obtained from the Framingham Heart Study. We first identified 190 CpG loci using elastic net Cox regression and subsequently constructed a survival prediction model based on the fusion of five complementary survival models by means of a neural network meta-learner. The prediction power of the survival model was evaluated in an external validation cohort, where we observed strong performance for predicting all-cause mortality that significantly exceeded PhenoAge and was statistically comparable to GrimAge. These performance estimates were derived in cohorts of European ancestry and externally validated in postmenopausal women aged 50-79 years, and should therefore be interpreted as applicable only to demographically similar populations.

Humans↗

PubMed2026

A First-in-Japanese Phase 1, Double-Blind, Placebo-Controlled, Parallel-Cohort Study of Sefaxersen, an Antisense Oligonucleotide Targeting Complement Factor B, in Healthy Participants.

Increased activity in the complement alternative pathway (AP) plays a key role in diseases such as IgA nephropathy (IgAN). This first-in-Japanese double-blind Phase 1 study investigated the pharmacokinetics (PK), pharmacodynamics (PD), safety, and tolerability of sefaxersen (RO7434656), an antisense oligonucleotide targeting complement factor B messenger RNA. Healthy participants were randomized equally into four cohorts: placebo or sefaxersen 20, 40, or 70 mg. The PK, PD, and safety endpoints were monitored throughout the study and during the 90-day follow-up period. All 24 participants completed the study, with no new safety signals or clinically meaningful changes in blood chemistry, electrocardiogram, or vital signs observed. Plasma sefaxersen concentration demonstrated a biphasic PK profile, characterized by an initial rapid decline followed by a slow elimination. Sefaxersen decreased PD markers related to the complement AP selectively, without affecting the classical pathway, in a dose-dependent manner, and the PD effects persisted over 2 to 3 months. Sefaxersen was well tolerated by healthy Japanese participants, with a manageable safety profile. These findings support the inclusion of Japanese patients with IgAN in the global Phase 3 study (IMAGINATION, NCT05797610).

Humans↗

PubMed2026

Differential contributions of mt-Tr and Cs variants to developmental cochlear defects and mitochondrial dysfunction in A/J mice.

A/J mice exhibit early-onset hearing loss linked to Cdh23, mitochondrial tRNA-Arg (mt-Tr), and citrate synthase (Cs) variants. Although developmental cochlear defects have been identified in juvenile A/J mice, the hierarchical contributions of mt-Tr versus Cs remain unclear. Using reciprocal intercross-derived strains to decouple mitochondrial haplotypes from nuclear factors, we demonstrate that the mitochondrial background is the primary determinant of auditory dysfunction. Mice with A/J mtDNA (AXB strains) displayed significantly higher ABR thresholds, accelerated hair cell attrition, and severe stereocilia dysmorphology compared to those with B6 mtDNA (BXA strains), occurring largely independently of the Cs genotype. While the Cs mutation exacerbated hearing loss, its impact was secondary to that of the dominant mitochondrial background. Systemic behavioral assessments and mitochondrial assays confirmed that A/J mitochondria exert a more profound metabolic impact than the Cs mutation. Our findings establish that the mitochondrial genomic background, with the mt-Tr locus as a prominent candidate variant, serves as the principal driver of developmental cochlear defects and early-onset hearing loss in A/J mice, while the nuclear Cs mutation acts as a synergistic modifier. This study underscores the critical role of mitonuclear crosstalk in inner ear maturation and provides new insights into the etiology of hereditary hearing loss.

Animals↗

PubMed2026

Self-reported physical activity in a randomized study from Norwegian Healthy Life Centres.

AIM: This study examines firstly if participation in a three-month intervention at Norwegian Healthy Life Centres (HLCs) improved self-reported physical activity (SR-PA), and secondly to what extent physical activity (PA) status at six months and changes from baseline were associated with demographic and motivational predictors. BACKGROUND: Regular PA is promoted as a central component of public health initiatives aimed at preventing noncommunicable diseases. METHODS: This randomized controlled trial included 118 participants (57 in the intervention group) recruited from HLCs in South-western Norway. The intervention effect was assessed by comparing the intervention group with the waiting-list control group after six months. We examined sociodemographic and motivational predictors of change combining both groups into a single cohort. This trial was registered at ClinicalTrials.gov (ID: NCT02247219). FINDINGS: At six-month follow-up, participants in the intervention group reported higher levels of SR-PA compared with the control group. The estimated effect was modest (B = 0.26, 95% CI -0.01 to 0.53), equivalent to ≈0.37 SD. Although the confidence interval included zero, the estimate remained compatible with a modest positive effect. Autonomous motivation and social support were positively associated with SR-PA after 6 months, while psychological defiance showed a negative association. Autonomous motivation and psychological defiance impacted PA change during the 6-month period in opposite directions.

Humans↗

PubMed2026

A systematic literature review of cultural concepts taught by pharmacist preceptors during pharmacy student experiential placements.

BACKGROUND: Cultural concepts such as cultural intelligence, awareness, competency and safety are essential in guiding culturally responsive care in health professional practice. Pharmacist preceptors play a pivotal role in sharing both clinical and cultural safe practice with pharmacy students. Culturally responsive care can contribute to achieving health equity, which is especially important for Indigenous communities. AIM: To review literature on cultural concepts in pharmacist preceptorship practices, and how these concepts are taught and communicated to pharmacy students during experiential learning. METHOD: The systematic review followed the PRISMA 2020 guideline. Scopus, PubMed, and Google Scholar were used to identify articles specific to pharmacist preceptors and pharmacy students published between 2015 and 2025, and available in English. RESULTS: Three full-text articles met the inclusion criteria. Major themes and subthemes were identified; pharmacist preceptors lacked preparedness to teach cultural concepts, resulting in variability in preceptors' understanding of cultural concepts and confidence in fulfilling preceptor responsibilities, underutilised structured frameworks to guide students' learning, challenges with preceptorship due to limited resources and support, and the influence of preceptorship on student learning, which impacted students' learning and competency. CONCLUSION: Pharmacy students had minimal exposure to culturally informed pharmacist preceptorship. It is likely that pharmacist preceptors require country-specific educational resources to support culturally safe preceptorship. Future research is required to substantiate these findings, and to guide culturally responsive practice and promote equitable health outcomes in diverse populations.

Humans↗

PubMed2026

Genome-wide characterization of the TGF-β superfamily identifies bmp15, gdf9, and gsdf as sex-biased candidate regulators of gonadal differentiation in the synchronous hermaphrodite Plectropomus leopardus.

The transforming growth factor-β (TGF-β) superfamily plays conserved roles in vertebrate reproduction and gonadal sex differentiation. However, its genomic repertoire and sex-biased expression patterns remain unclear in the leopard coral grouper (Plectropomus leopardus), a species with synchronous hermaphroditism. Here, we performed a genome-wide identification of the TGF-β superfamily, identifying 42 genes from the chromosome-level genome. Phylogenetic and synteny analyses indicated that segmental duplication under purifying selection contributed to family expansion. Expression profiling across multiple tissues and four gonadal developmental stages (undifferentiated, 120 dph; early differentiated, 15 months; mature testis, 3 years; mature ovary, 3 years) identified eight gonad-enriched genes, among which bmp15 and gdf9 exhibited pronounced female-biased expression, with transcripts localized exclusively to the oocyte cytoplasm, particularly in stage II-III oocytes. In contrast, gsdf showed male-biased expression and was localized in spermatogenic cells of the testis. These reciprocal expression patterns indicate that bmp15/gdf9 and gsdf are candidate factors associated with gonadal sex differentiation. Our study provides the first comprehensive characterization of the TGF-β superfamily in P. leopardus and highlights bmp15, gdf9, and gsdf as candidate sex-differentiation factors in this hermaphroditic species.

Animals↗

PubMed2026

Chronic postsurgical pain: risk assessment and mitigation.

PURPOSE OF THE REVIEW: Chronic postsurgical pain (CPSP) and persistent postoperative opioid use (PPOU) are two of the most common complications of a number of surgical interventions, which can cause significant personal and economic negative consequences. This review outlines known and potential risk factors for CPSP and PPOU and approaches to reduce these risk factors. RECENT FINDINGS: Modifiable risk factors for developing CPSP include psychological distress, preoperative pain intensity, and perioperative opioid exposure. Although less studied, psychological comorbidities are also risk factors for PPOU. Evidence-based mitigation strategies include psychological interventions and perioperative opioid sparing. SUMMARY: A number of perioperative risk factors for developing CPSP and PPOU have been identified, and anesthesiologists should be cognizant of these risk factors and potential risk mitigation strategies. Additional prospective studies are needed to further develop easily adoptable, evidence-based interventions to reduce the incidence of CPSP and PPOU.

Humans↗

PubMed2026

A systematic review of qualitative research on HIV and food insecurity in high-income countries.

OBJECTIVES: Food insecurity leads to adverse health outcomes in people living with HIV, including obesity, poor mental health and viral non-suppression. Qualitative studies in low- and middle-income countries have described the impact of food insecurity on medication adherence. However, limited qualitative research exists on the lived experiences of food insecurity among people living with HIV in high-income countries (HICs). We aimed to synthesize qualitative literature on food insecurity among people living with HIV in HICs. DESIGN: Systematic review and textual narrative synthesis. METHODS: We searched MEDLINE, CINAHL, Scopus, Embase, and PsycINFO, extracting data from included articles on a standardized form in Covidence. We synthesized literature using a textual narrative approach. We conducted quality appraisal (Critical Appraisal Skills Programme Qualitative Studies Checklist) and graded certainty of findings (GRADE-CERQual). RESULTS: We reviewed 2772 articles, reduced to 940 after deduplication, with 12 articles included after full text screening. Included articles reported on studies conducted in the United States ( n  = 7), and Canada ( n  = 5). We identified three key themes, each with their own sub-themes: the role of structural inequalities in shaping and navigating food insecurity; the impacts of food insecurity on health and wellbeing; and the labour of acquiring of food. CONCLUSIONS: Our review highlights the syndemic nature of food insecurity and HIV; intersecting experiences of multiple structural hardships constellate and interact synergistically to amplify poor health outcomes. Interventions should address the multiple and reinforcing social and structural conditions that shape food insecurity among people living with HIV.

Humans↗

PubMed2026

Integration of ear and hearing care services in low- and middle-income health systems: a systematic review and qualitative synthesis.

Hearing loss is a global public health burden and mostly affects those living in low- and middle-income countries (LMICs). One approach to address ongoing challenges is the World Health Organization's recommendation for the integration of ear and hearing care (EHC) services into healthcare packages. However, little is known about EHC integration approaches, particularly in LMICs additionally, these approaches have not been investigated through a health systems lens. This qualitative review aimed to describe the various approaches to the EHC service integration in LMICs and to identify enabling and constraining factors. We reviewed 17 studies, with a focus on LMICs, using adaptations of the Valentijn integration and World Health Organization EHC frameworks, following the PRISMA guidelines. Our investigation showed that most integration approaches were at micro or individual level. Enabling factors for integration of EHC services were training, mentorship, collaboration, technology, inclusion of EHC in healthcare packages and investment in EHC services. Barriers were challenges with training, facilities and equipment, policy implementation and resourcing of EHC services. We further described factors influencing healthcare seeking behaviour and the use of integrated EHC services, such as access and ability to pay, referral systems and communication and awareness. This study describes the complex nature of EHC integration and ways to support integration. Key considerations are the level of integration, training to address workforce issues and factors influencing service utilisation as we work towards health system strengthening.

Humans↗

PubMed2026

Robotic Needle Insertion for CT-guided Percutaneous Biopsy of Thoracoabdominal Lesions: A Prospective Multicenter Randomized Trial.

Purpose To compare safety and feasibility between a novel CT-guided robotic system and the conventional freehand technique for puncture biopsy of thoracoabdominal lesions. Materials and Methods In this prospective multicenter randomized trial, individuals with suspected lesions were enrolled between July 2023 and April 2024 across three university teaching hospitals and randomized to the robot-assisted group (n = 82) or the freehand group (n = 83). Procedure outcomes included the technical success rate, targeting error, number of CT scans and needle adjustments, puncture time, and complications. Descriptive and inferential statistics were calculated. Results A total of 165 participants (mean age, 60 years ± 10 [SD]; 83 male) were included. Compared with the freehand group, the robot-assisted group demonstrated a higher technical success rate (97.56% [80 of 82] vs 62.65% [52 of 83], P < .001), lower targeting error (mean Euclidean deviation: 1.7 mm ± 1.1 vs 4.5 mm ± 3.9, P < .001), and fewer CT scans (mean, 4.3 ± 1.9 vs 5.2 ± 2.3; P = .002) and needle adjustments (mean, 0.7 ± 0.7 vs 1.6 ± 1.6; P = .003). Despite differences in geometric precision, both groups achieved 100% (82 of 82 and 83 of 83) diagnostic yield. The median puncture time was comparable between groups (5.5 minutes ± 4.3 vs 4.8 minutes ± 7.0, P = .50). During lung biopsies, the robot-assisted approach yielded fewer complications compared with the freehand approach (4.88% [four of 82] vs 16.87% [14 of 83], P = .014). Conclusion Compared with the freehand approach, robot-assisted biopsy yielded greater precision and reduced adjustments and complications while demonstrating noninferior diagnostic efficacy and comparable duration. Keywords: Robotic Needle Insertion, Biopsy, Thoracoabdominal Lesions, Robot-assisted Biopsy, CT-guided Intervention, Percutaneous Needle Biopsy, Randomized Controlled Trial, Algorithm Development, CT, Clinical Testing, Interventional-Body, Biopsy/Needle Aspiration, Percutaneous, Thorax, Abdomen/GI, Liver, Lung, Kidney ©RSNA, 2026.

Humans↗

PubMed2026

Xerophthalmia and ocular manifestations of vitamin A deficiency in children in high-income countries: A systematic review.

Xerophthalmia is a vision-threatening eye condition caused by vitamin A deficiency (VAD). Cases of xerophthalmia in high-income countries (HICs) are vulnerable to misdiagnosis, causing delays in treatment and adverse visual outcomes. We define the features, causes and complications of VAD and xerophthalmia in children of HICs. Our study followed the Preferred Reporting Items for Systematic Reviews and Meta-analyses guidelines (CRD42024492023). We performed a search for eligible articles on Scopus, Web of Science, Cochrane, PubMed and Medline. Cases reporting on children under 18 years of age residing in HICs with ocular features of VAD were eligible for inclusion. The search yielded 2474 results; 43 case reports and case series met the inclusion criteria consisting of a total of 61 cases (mean age 9.9 ± 4.2 years, range 3-17 years). Xerophthalmia was graded according to the most advanced finding for each case: 21.3% had night blindness only; 29.5% had conjunctival xerosis or Bitot spots; 29.5% had corneal xerosis, ulceration or scarring; 1.6% had xerophthalmia fundus only; and 18.0% had ocular manifestations associated with VAD that are not encompassed under the WHO classification. These features included swollen optic discs, optic neuropathy, or ocular dryness. Restrictive dietary practises were the most common mechanism of deficiency (75%), and autism was the most common underlying condition (49%). This shows that VAD remains a cause of severe visual impairment in HICs, especially when associated with delays in diagnosis and treatment. Further research is required to establish the prevalence of xerophthalmia in HICs.

Humans↗

PubMed2026

The return of measles: a dangerous comeback.

PURPOSE OF REVIEW: Measles has reemerged as a significant global public health threat, with increasing morbidity and mortality associated with declining vaccination rates. This review summarizes current global outbreaks, history of measles, vaccination and elimination status, vaccine hesitancy, and outbreak response and lessons learned highlighting different novel digital epidemiological tools. RECENT FINDINGS: Measles continues to surge worldwide with an estimated 11 million infections in 2024, which is more than prepandemic levels. Developing and developed countries are both facing measles outbreaks, with the United States at risk of losing measles elimination status. Recent studies have showed that worldwide percentages of two-dose measles vaccination were lower than 95% that is required to interrupt measles transmission in all WHO regions. Novel epidemiological tools such as interactive simulators, real-time use of dynamic models, serosurveillance, and others are transforming measles outbreak response and enable earlier outbreak detection, tracking, and targeted public health interventions. SUMMARY: Vaccine hesitancy is one of the top global health threats and developing a tailored evidence-based approach is necessary to establish and maintain measles elimination.

Humans↗

PubMed2026

Transcriptomic changes in the gut mucosa of fasting northern elephant seal pups reveal immune modulation during early microbiome establishment.

Fasting is an integral component of the life-history of many species. Following abrupt weaning, northern elephant seal pups (Mirounga angustirostris) undergo an extended post-weaning fast of approximately 60 days. During this period, enteric bacterial diversity increases, suggesting that host immune regulation may facilitate the establishment of microbial communities. However, the molecular processes occurring within the intestinal mucosa during this transition remain poorly understood. To investigate these mechanisms, we characterized transcriptional changes in the enteric mucosa of male and female northern elephant seal pups sampled at weaning and after one month of fasting. Total RNA isolated from rectal swabs was sequenced and aligned to the Mirounga angustirostris reference genome. Differential gene expression and gene set enrichment analyses were used to identify genes and pathways associated with fasting and sex-specific responses. Fasting was accompanied primarily by transcriptional downregulation, including genes involved in antimicrobial defense, inflammation, protein turnover, and epithelial remodeling. In contrast, several genes associated with B-cell activity and immune recognition were upregulated. Gene Set Enrichment Analysis revealed coordinated activation of immune-regulatory pathways indicating dynamic modulation of intestinal immunity rather than generalized immune suppression. Pronounced sex-specific differences were also observed. Male pups exhibited transcriptional patterns consistent with enhanced immune tolerance, whereas females showed broader immune-pathway activation, including enrichment of pro-inflammatory and stress-response pathways. Several non-coding RNAs also displayed sex-specific changes in expression. Together, these findings suggest that fasting induces transcriptional remodeling of the gut and may contribute to immune regulation during a critical period of microbiome establishment in northern elephant seal pups.

Animals↗