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Unacknowledged Burdens and Clinical Assets of BIPOC Genetic Counseling Students: Qualitative Evidence to Inform Supervision.

As the genetic counseling profession works to diversify its predominantly white workforce, understanding the experiences of Black, Indigenous, and People of Color (BIPOC) students is central to equity efforts. While BIPOC students bring invaluable cultural and linguistic diversity that improves patient care, they often navigate clinical training environments that lack diversity and psychological safety. This article draws on data from a longitudinal constructivist qualitative study to examine how racial and ethnic concordance (or lack thereof) with patients and clinical supervisors influenced the clinical training, professional development, and well-being of BIPOC genetic counseling students. Semi-structured interviews were conducted with 25 BIPOC genetic counseling students in the United States and Canada. Interviews were recorded using Zoom.us, transcribed using Rev.com, and analyzed in NVivo using reflexive thematic analysis. The analysis led to the construction of three themes: (1)Shared identity with patients is a clinical advantage: Participants leveraged their cultural and linguistic intuition to establish trust and rapport with patients; (2) Identity navigation involves cognitive and emotional labor: Participants shouldered an unacknowledged burden in managing stereotype threat, overcoming feelings of exclusion, and educating supervisors; and (3) Racial/ethnic identity shapes supervisory dynamics: Participants described BIPOC supervisors as providing identity-affirming support, while some white supervisors avoided discussions about identity or committed microaggressions. These results suggest that BIPOC genetic counseling students have clinical assets rooted in biculturalism, yet carry a burden that often goes unacknowledged of managing power imbalances and pressure to assimilate in predominantly white clinical supervision spaces. To promote equitable training, programs should implement supervisor training on culturally responsive identity broaching, establish independent, transparent mechanisms for students to report biases they encounter in clinic, and expand mentorship networks to provide additional support.

Humans

In vivo genome-wide CRISPR screens identify FOXR1 as a suppressor of CD8+ T cell antitumor immunity.

T cell dysfunction critically limits the efficacy of T cell-based immunotherapies in solid tumors, yet the intrinsic regulators of T cell dysfunction remain incompletely understood. Through an in vivo genome-wide CRISPR screen in tumor-infiltrating CD8+ T cells, we identified Forkhead Box R1 (FOXR1) as a potent transcriptional suppressor of CD8+ T cell effector functions. Genetic ablation of FOXR1 significantly enhanced cytokine production and cytotoxic capacity in both murine and human CD8+ T cells, whereas its overexpression impaired T cell activation and effector molecule expression. Mechanistically, multiomics integration of RNA-seq, CUT&Tag-seq, and ATAC-seq revealed that FOXR1 binds directly to promoter regions of key effector genes, including IL2, GZMB, and PRF1, and represses their expression. Importantly, FOXR1 deletion in human anti-CD19 CAR T cells improved their efficacy against solid tumors, demonstrating that FOXR1 is a checkpoint of T cell effector function and targeting FOXR1 is a promising strategy to enhance CAR T cell efficacy against solid tumors.

Animals

Associations Between Routine Vaccinations and the Risk of New-Onset Idiopathic Uveitis.

OBJECTIVE: To evaluate the association between vaccination and the risk of new-onset idiopathic uveitis (NIU). DESIGN: Retrospective cohort study of aggregated electronic health records from multiple health systems across the United States. SUBJECTS: Subjects who received the coronavirus disease 2019 (COVID-19), human papillomavirus (HPV), varicella, recombinant herpes zoster, or live herpes zoster vaccinations from 2006 to 2025 and propensity-score matched controls. INTERVENTION: Vaccines against COVID-19, HPV, varicella, recombinant herpes zoster, or live herpes zoster. MAIN OUTCOMES AND MEASURES: The main outcome was the incidence of NIU at 3, 6, and 12 months following vaccination. Vaccinated patients were compared with matched controls who did not receive the respective vaccines. Analyses were repeated, excluding patients with previous diagnosis of the respective viral infection. Risk ratios (RR) with 95% confidence intervals (CIs) were calculated for overall NIU and constituent subtypes (anterior, intermediate, posterior, and panuveitis). RESULTS: All tested vaccinations were associated with reduced risk of NIU through 12 months compared with matched controls. Relative risk reductions were 65% for COVID-19 (RR, 0.35; CI, 0.33-0.37), 56% for HPV (RR, 0.44; CI, 0.35-0.54), 71% for varicella (RR, 0.29; CI, 0.25-0.33), 68% for live zoster (RR, 0.32; CI, 0.23-0.43), and 69% for recombinant zoster vaccination (RR, 0.31; CI, 0.26-0.37). Similar reductions were observed after excluding patients with prior diagnoses of the respective viral infections. CONCLUSIONS: Vaccination was associated with a lower risk of idiopathic uveitis, representing the complex interplay between immune modulation and the development of NIU.

Humans

A hybrid effectiveness-implementation trial to integrate precision skin cancer risk feedback in federally qualified health centers.

BACKGROUND: Skin cancers are the most common type of cancer in the United States, occur in all segments of the population, and are preventable. Our previous research with primary care patients' demonstrated interest in and efficacy of a precision prevention intervention providing feedback on MC1R risk level (higher versus average) in combination with prevention education materials relative to a standard educational intervention. Our current study is a hybrid type 1 effectiveness-implementation trial deployed at six federally-qualified health centers. This paper presents the study protocol. METHODS: A community advisory panel will guide development of study materials and measures. Staff training at each clinic will be completed in-person. Patients will be approached and screened in-person. Those completing genetic testing and the baseline survey will be randomized to the precision versus standard intervention for each risk level with a target sample size of 286 for each combination. Primary outcomes of effectiveness, assessed at 6 and 12 months, include a tanning score (5 items assessing intentional and unintentional tanning), number of sunburns, conduct of a skin self-examination, and electronic health record documentation of clinician-patient communication about skin cancer prevention. Effectiveness comparisons will focus on the precision relative to the standard intervention among higher risk participants. Implementation data will be collected to identify barriers and facilitators. RESULTS: Effectiveness and implementation outcomes will be evaluated following study completion. CONCLUSIONS: Results will guide subsequent scale-up of the precision intervention, including modifications of the intervention as well as methods for implementation. CLINICAL TRIALS IDENTIFIER: NCT07222995.

Humans

Influencer-driven lifestyle and wellness framing of intoxicating hemp products may normalize youth cannabis use.

Hemp-derived intoxicating cannabis products (DICPs) have rapidly expanded across the U.S. marketplace and are increasingly promoted on social media platforms popular among youth. This commentary highlights emerging concerns about influencer-driven DICP promotion on Instagram, where intoxicating hemp and cannabis products are embedded within lifestyle, wellness, fitness, sobriety, harm-reduction, and entertainment narratives. In ongoing monitoring of Instagram posts from leading DICP brands, we observed influencer posts that featured young-looking creators, aspirational wellness imagery, humor, slang, fast-cut editing, mocktail-making scenes, and claims positioning DICPs as "hangover-free," safer, or substitutes for alcohol or other drug use. Such content may reduce perceived risk, increase product appeal, and normalize cannabis use, particularly when promotional posts resemble organic (non-promotional) peer-culture content rather than advertising. Existing platform guidelines and regulatory approaches may inadequately address this form of influencer marketing. Enforcement is more actionable when sponsorship is clearly disclosed; however, influencers often omit brand sponsorship disclosures entirely or use vague disclosures. The absence of a disclosure does not necessarily mean that a post is non-promotional. Platforms should develop policies and algorithm-assisted surveillance approaches that identify DICP influencer content using youth-oriented cues, lifestyle and wellness framing, brand tags or links, and unverified reduced-risk or therapeutic claims.

Humans

Functional neuroimaging subtypes of obsessive-compulsive disorder: A systematic review and meta-analysis.

Obsessive-compulsive disorder (OCD) exhibits substantial clinical heterogeneity that may reflect underlying neurobiological diversity. Neuroimaging-based subtyping may advance precision psychiatry by identifying biologically distinct subgroups with differential treatment responses. This study systematically synthesized evidence from functional neuroimaging subtyping studies in OCD to identify reproducible neurobiological subtypes, characterize their clinical profiles, and establish a consensus-based classification framework. We reviewed 40 original studies employing machine learning, clustering, normative modeling, or classification approaches, encompassing approximately 8,150 patients. Consensus clustering identified three reproducible neurobiological subtypes. The Limbic-Hyperactive subtype, comprising approximately 40% of patients, exhibited amygdala and insula hyperconnectivity, elevated anxiety levels, predominant contamination and washing symptoms, and favorable response to cognitive-behavioral therapy. The Fronto-Striatal-Hypoconnected subtype, comprising approximately 35% of patients, demonstrated reduced orbitofrontal-striatal connectivity, cognitive inflexibility, predominant checking and ordering symptoms, and a favorable response to selective serotonin reuptake inhibitors. The Global-Disrupted subtype, comprising approximately 25% of patients, exhibited widespread connectivity disruption, greater symptom severity, and poor treatment response. Support vector machine classification achieved 81.5% accuracy for subtype assignment, though classification of OCD versus healthy controls showed limited generalizability in multisite settings (AUC 0.567-0.673). These findings support a neuroimaging-based framework for personalized treatment selection but require prospective validation.

Humans

Driving Under the Influence of Cannabis Among U.S. Young Adults Who Use Cannabis: Evidence From the 2021-2024 National Survey on Drug Use and Health.

PURPOSE: To estimate the prevalence of driving under the influence of cannabis (DUIC) and identify associated factors among U.S. young adult drivers reporting past-year cannabis use. METHODS: This cross-sectional study analyzed pooled 2021-2024 National Survey on Drug Use and Health. The analytic data were restricted to drivers aged 18-25 years who reported past-year cannabis use (N = unweighted 17,141; weighted N = 10,814,381). The outcome was self-reported past-year DUIC. Independent variables included demographics, substance use, mental health, cannabis-related perceptions, and driving behaviors. These relationships were assessed by modified Poisson regression. RESULTS: The weighted prevalence of DUIC was 28.0%, representing approximately over three million young adults. DUIC prevalence increased with cannabis use frequency, from 2.51 times higher among those using cannabis 12-49 days (adjusted prevalence ratio [APR]: 2.51; 95% confidence interval [CI]: 2.29-2.75) to 3.63 times higher among those reporting use on 300-365 days (APR: 3.63; 95% CI: 3.60-3.76), compared with those using cannabis 1-11 days. Cannabis use disorder (APR: 2.34; 95% CI: 2.06-2.65), simultaneous alcohol and cannabis use (APR: 1.29; 95% CI: 1.28-1.30), and perceived easy cannabis availability (APR: 2.36; 95% CI: 2.33-2.39) were also associated with higher prevalence of DUIC. Nonenrollment in school and living in a state with a medical cannabis law were associated with lower DUIC prevalence. DISCUSSION: DUIC is highly prevalent among U.S. young adults who use cannabis, with a clear graded association across categories of cannabis use frequency. Public health interventions should address frequent use, cannabis use disorder, alcohol-cannabis co-use, and perceived cannabis availability.

Humans

Cryo-EM structure of TGFBIp fibrils driven by a corneal dystrophy-linked mutation enables design of peptide inhibitors of aggregation.

Corneal dystrophy is a heterogeneous group of diseases which manifests clinically by progressive corneal opacity and diminishing visual acuity. A group of corneal dystrophies are linked to autosomal dominant mutations in transforming growth factor β-induced protein (TGFBIp) and characterized by extracellular amyloid-positive deposits of unknown molecular structure. Here, we determined the cryogenic-electron microscopy (cryo-EM) structure of amyloid fibrils formed by the TGFBIp FAS1-4 domain with corneal dystrophy-linked mutation V624M. The L569 to N609 fibril core, which includes the Y571-R588 segment enriched in patient corneal deposits, forms symmetrical protofilaments with internal solvent channels. Leveraging this structure, we designed peptide inhibitors intended to bind onto fibril ends to block elongation, targeting the unequal growth of symmetrical protofilaments. Our G1 and H4 inhibitors exhibit concentration-dependent reduction of TGFBIp FAS1-4 aggregation as assessed by Thioflavin T, solubility fractionation, and electron microscopy. Our work illustrates how fibril structures can guide rational inhibitor design and suggests the targeting of protein aggregates as a therapeutic approach for corneal and ocular diseases.

betaIG-H3 Protein

Comparison of a 755-nm picosecond laser and a 1565-nm nonablative fractional laser for the treatment of atrophic acne scars: a 20-week prospective, randomized, split-face clinical study.

To compare the efficacy and safety of a 755-nm picosecond laser with a diffractive lens array (P-DLA) and a 1565-nm nonablative fractional laser (NAFL) for the treatment of atrophic acne scars. Twenty-seven patients with atrophic acne scars underwent three sessions of randomized split-face treatment with P-DLA and NAFL at 4-week intervals. Patients were followed up at 1, 2, and 3 months after the final treatment. Efficacy was assessed using the &#xc9;chelle d'&#xc9;valuation Clinique des Cicatrices d'Acn&#xe9; (ECCA) grading scale, the Investigator's Global Assessment (IGA) score, patients' self-rated improvement, and overall satisfaction. Treatment-related adverse reactions were recorded daily by patients until resolution. Both modalities demonstrated significant improvements in scar appearance based on ECCA score, IGA score, and patients' self-rated improvement (P&#x2009;<&#x2009;0.001). No statistically significant differences in efficacy were observed between the two treatments. However, the P-DLA group showed higher patient satisfaction (P&#x2009;=&#x2009;0.035) and a more favorable safety profile, including shorter durations of erythema and edema and the absence of crusting. Both P-DLA and NAFL were effective and safe for the treatment of atrophic acne scars, with similar efficacy. P-DLA offered better tolerability.

Humans

Decoding tumor immune microenvironment heterogeneity by single-cell and spatial multi-omics: From immunotherapy resistance to translational biomarkers.

Immune checkpoint blockade has transformed cancer therapy, yet primary and acquired resistance remain major clinical challenges. Increasing evidence indicates that immunotherapy resistance cannot be fully explained by tumor-intrinsic alterations or conventional biomarkers such as PD-L1 expression, tumor mutational burden, or microsatellite instability. Instead, therapeutic response is shaped by the tumor immune microenvironment (TIME) as a heterogeneous, spatially organized, and dynamically evolving ecosystem. Single-cell omics has revealed diverse immune and stromal cell states, including progenitor and terminally exhausted T cells, suppressive myeloid programs, B-cell/TLS-associated immune-reactive states, and CAF-mediated exclusion phenotypes. Spatial transcriptomics, spatial proteomics, and imaging-based approaches further demonstrate that these cell states assemble into distinct immune niches, including immune-inflamed, T-cell-excluded, myeloid-suppressive, metabolic/hypoxic, and TLS-associated niches. These spatial ecosystems determine whether antitumor immune cells can access malignant cells, receive antigen-presenting support, or become restrained by stromal, vascular, metabolic, and myeloid barriers. In this review, we summarize how single-cell and spatial multi-omics redefine TIME heterogeneity in immunotherapy resistance, highlight ligand-receptor communication networks linking cell states to spatial immune dysfunction, and discuss emerging translational biomarkers for patient stratification. We further propose that future immunotherapy biomarkers should evolve from static single-marker assays toward longitudinal, spatially resolved, and interpretable multi-omics models that guide precision combination immunotherapy.

Humans

Effects of a situational interest-based rotational fitness training program on positive affect in university students: A randomized controlled trial.

BACKGROUND: To evaluate whether a 12-week situational interest-based rotational fitness program improved positive emotional states in university students, to compare module-specific effects, and to examine whether the intervention moderated the heart rate-emotion association. METHODS: In this 2-arm randomized controlled trial, 560 freshmen from 10 Chinese universities were assigned to an experimental (n&#x2005;=&#x2005;280) or control group (n&#x2005;=&#x2005;280). The experimental group completed weekly 90-minute sessions covering strength, endurance, speed, and agility modules; controls received regular physical education. Positive emotional states were assessed using the positive well-being subscale of the Subjective Exercise Experiences Scale through ecological momentary assessment at 3 points per session, yielding over 14,000 observations. Linear mixed-effects models tested group, time, group&#x2005;&#xd7;&#x2005;time, heart rate, and heart rate&#x2005;&#xd7;&#x2005;group effects. Assessors and analysts were blinded. Ethical approval for the trial was granted by the Institutional Review Board of Capital University of Physical Education and Sports (2025A055). RESULTS: Improvement was greater in the experimental group than in controls (EMM change: 1.843 vs 0.505; difference&#x2005;=&#x2005;1.338, 95% confidence interval [CI]: 1.275-1.400, P&#x2005;<&#x2005;.001). At week 12, the raw between-group difference was 1.85 (d&#x2005;=&#x2005;2.23), and all group&#x2005;&#xd7;&#x2005;week interactions from weeks 2 to 12 were significant. Heart rate positively predicted emotional states in controls (B&#x2005;=&#x2005;0.005, 95% CI: 0.003-0.007), but this association was attenuated in the experimental group (interaction B&#x2005;=&#x2005;-0.008, 95% CI: -0.011 to -0.005). Strength and agility showed significant improvements, while endurance produced consistently higher emotional states across assessment points. Heart rate moderation was significant for strength and endurance, but not speed or agility. CONCLUSION: The rotational program improved positive emotional states more than regular physical education, although effects varied by module. Strength showed the most robust benefit. The program also weakened, but did not eliminate, the heart rate-emotion association during more demanding activities.

Humans

Evolution of maize recombination landscape during domestication.

Despite the plethora of knowledge about the benefits of meiotic recombination and numerous theoretical studies examining how recombination rates evolve, there is a general lack of empirical support and consensus across species. To fill this knowledge gap, we characterized the evolution of recombination landscape in maize during its domestication from teosinte and related the observed changes to established theoretical frameworks. Through examining recombination in experimental populations of maize and teosinte and the population genomics approach of identifying historical recombination events using ancestral recombination graph inference to generate saturated maize and teosinte recombination maps, we found that during domestication, maize experienced a 12% increase in its genome-wide recombination rate. Furthermore, maize evolved higher recombination rates on the long arms of chromosomes in regions closer to centromeres, where recombination is generally very low. The repatterning of crossover events came from changes in global crossover positioning rather than alterations in cis-acting chromatin factors. Consequently, we found evidence of selection acting on trans-acting recombination modifiers affecting crossover interference and controlling the interference-dependent class I crossover pathway. We show that CO repatterning was likely beneficial for maize fitness, as significant recombination rate increases were predominantly in gene-rich regions, which harbor domestication-related variation. This work suggests genomic and mechanistic processes leading to the evolution of meiotic recombination landscape in response to directional selection pressure and provides evidence for the evolutionary advantage of recombination.

Zea mays

eIF5A and polyamines restrict mRNA levels in response to ribosome stalls.

Obstacles to translation elongation stall ribosomes and allow deleterious proteins to accumulate, which threatens cellular health. Cells recognize and clear stalled ribosomes via several interrelated pathways, although the mechanisms by which cells distinguish stalled from normally elongating ribosomes and mount an appropriate response are incompletely understood. While recent work highlights how ribosome collisions help cells to recognize stalled ribosomes, how other factors contribute to detection remains unclear. Here, we report a requirement for the translational factor eIF5A in the mRNA decay response to ribosomal stalling, i.e., No-Go mRNA Decay (NGD). We identified the Caenorhabditis elegans polyamine transporter, catp-6, via a forward genetic screen as a factor required for NGD. During our mechanistic dissection of the catp-6 phenotype, we uncovered a role for cellular polyamines and the translation elongation factor eIF5A in NGD, and we show this requirement is conserved from C. elegans to Saccharomyces cerevisiae. Our analyses support the idea that cells use eIF5A to identify ribosomal stalls and execute NGD and uncover a molecular function for a core protein synthesis factor in limiting expression from stall-inducing mRNAs. Our work offers insight into how cells identify and remove problematic mRNAs from the translational pool. Our work also raises the possibility that dysregulated mRNA decay is an unrecognized pathophysiology associated with polyaminopathies and eIF5A disorders, of relevance to varied neurodegenerative and aging phenotypes and efforts to pharmacologically inhibit eIF5A.

Animals

Effect of Music on Pain, Anxiety, and Satisfaction During Intrauterine Device Application: A Randomized Clinical Trial.

This randomized controlled trial aimed to determine the effect of music played during intrauterine device (IUD) insertion on perceived pain, state anxiety, and satisfaction levels. The study was conducted with 70 women who applied to a maternal and child health and family planning center and were randomly assigned to the intervention and control groups using simple randomization. Data were collected using a Demographic Information Form, the State-Trait Anxiety Inventory (STAI-I), and the Visual Analog Scale (VAS), as well as Bluetooth speakers and the musical piece Evgeny Grinko-Valse. Participants in the intervention group listened to music before and during the IUD insertion procedure, whereas the control group received routine care only. Data were analyzed using SPSS version 26 with appropriate descriptive and inferential statistical methods. Women in the music group had significantly lower perceived pain (p&#x2009;<&#x2009;0.001) and state anxiety levels during the procedure (p&#x2009;=&#x2009;0.022), and significantly higher satisfaction levels compared with the control group (p&#x2009;<&#x2009;0.001). In addition, post-procedure state anxiety levels were positively correlated with pain intensity experienced during and after the procedure (r&#x2009;=&#x2009;0.542 and r&#x2009;=&#x2009;0.496, respectively; p&#x2009;<&#x2009;0.001), and negatively correlated with procedural satisfaction (r&#x2009;=&#x2009;-0.652; p&#x2009;<&#x2009;0.001). These findings suggest that listening to music during IUD insertion may help reduce pain and anxiety while potentially enhancing patient satisfaction. Trial Registration: NCT06215183.

Humans

A host-encoded prophage targets a Candidate Phyla Radiation bacterium and shapes episymbiotic interactions.

The Patescibacteriota, also known as the Candidate Phyla Radiation (CPR), represent a large lineage of ultrasmall bacteria with highly reduced genomes and obligate dependence on bacterial hosts. Although genomic analyses have revealed CRISPR-Cas and restriction-modification systems in many CPR genomes, no cognate bacteriophages (phages) have been isolated, leaving CPR-phage interactions unexplored. Nanosynbacter lyticus TM7x, the first cultivated CPR bacterium, grows episymbiotically on its host, Schaalia odontolytica XH001, in the human oral microbiome. Here, we identify Xhp1, an inducible prophage of XH001 that is preferentially activated during episymbiosis with TM7x. Released Xhp1 particles infect prophage-free XH001 via distinct strategies determined by host growth mode, establishing lysogeny under planktonic conditions but driving lytic infection during surface-associated growth. Xhp1 also binds efficiently to TM7x and exhibits limited infection under the conditions tested, indicating direct phage-CPR interactions. Importantly, TM7x modulates Xhp1 availability in a spatially dependent manner. In planktonic culture, free-floating TM7x reduces lysogenic conversion of XH001&#x394;Xhp1, consistent with TM7x acting as a phage sink that lowers effective phage concentration. In contrast, during surface-associated growth, TM7x increases XH001&#x394;Xhp1 susceptibility to lytic infection, likely by locally concentrating phage particles within a constrained niche. These results demonstrate that CPR bacteria can regulate viral encounter rates through spatial organization. In spatially structured environments such as oral biofilms, such modulation may shape infection dynamics and community structure. Together, this work characterizes the first CPR-targeting phage and reveals a an important role for phages in CPR-host bacteria interactions.

Prophages

LINE-1 repeats are a defining feature of the Xce.

During early development, female mammals inactivate one X chromosome to balance their X-linked gene dosage with males. While allelic choice is random in inbred mouse populations, choice can be significantly skewed in interstrain hybrids. The genetic basis of skewing has long been attributed to the mysterious "X chromosome controlling element(s)" (Xce) with different strengths among species, subspecies, and strains. When two X-chromosomes with different Xce strengths are inherited by offspring, the X chromosome with the stronger Xce will have a higher probability of remaining active. Here, we provide evidence that L1Tf repeats-a subfamily of long interspersed nuclear elements 1-plays a role in determining Xce strength. L1Tf elements form a condensed core within the inactive X (Xi) territory. Mouse strains with varying Xce strengths differ in the L1Tf copy number on the X chromosome, with the strength of the Xce allele being inversely related to L1Tf copy number. L1Tf expression mediates the Xce effect. However, in contrast to a prior report, L1Tf RNA does not coat the Xi. Rather, L1Tf promotes condensation of the Xi core. Intriguingly, L1Tfs recruit and sequester YY1 from active genes, accelerating XCI in cis. Thus, L1Tf copy number, expression, and binding of YY1 are key defining features of the Xce. We propose a model in which the Xce influences the choice of Xist alleles by promoting YY1 binding to the nucleation site for the initiation of Xist spreading.

Animals

Sexual selection purges mutation load, but not overall genetic diversity, decreasing vulnerability to extinction.

Theory suggests sexual selection will enhance population viability by purging deleterious alleles. However, direct genomic evidence for this fundamental idea is scarce and contradictory. We combined long-term experimental evolution with whole-genome resequencing to directly test how sexual selection affects mutation load, genomic divergence, and extinction risk in small populations (maximum Ne = 40) of Tribolium castaneum. After 156 generations, populations evolving under strong sexual selection carried substantially fewer deleterious alleles than populations under weak sexual selection, based on both individual-level estimates of missense and nonsense variants and population-level Rxy analyses, indicating more efficient purging of deleterious alleles. In contrast, nucleotide diversity and runs of homozygosity were similar across treatments, indicating that purging acted most strongly on deleterious variation, and that reduced mutation load in these small populations under strong sexual selection was not explained by demographic effects. Importantly, population-level mutation load estimates best explained extinction risk under inbreeding, directly linking sexual selection to purging and population viability. Genome scans of high and low sexual selection populations revealed peaks of divergence, which included genes involved in courtship, sex discrimination, and seminal fluid proteins. Our results provide direct genomic evidence that sexual selection can reduce mutation load without eroding standing genetic diversity and thus adaptive potential, while driving adaptive divergence in reproductive traits. This beneficial purging may help explain the widespread prevalence of sexual reproduction in nature despite inherent costs and have important ramifications as to how we manage populations of conservation concern.

Animals

High-frequency contralesional dorsal premotor cortex and low-frequency contralesional primary motor cortex rTMS in subacute stroke with severe upper limb impairment: comparable motor outcomes and differential regional degree centrality changes.

BACKGROUND: The contralesional dorsal premotor cortex has been proposed as a potential neuromodulatory target for patients with severe upper limb impairment due to subacute ischemic stroke. This proof-of-concept study aimed to compare behavioral outcomes and resting-state neuroimaging findings between high-frequency repetitive transcranial magnetic stimulation (rTMS) over the contralesional dorsal premotor cortex and guideline-supported low-frequency stimulation over the contralesional primary motor cortex. METHODS: In this randomized trial, 46 patients with severe upper limb impairment in the subacute stage after ischemic stroke were randomly assigned to receive either high-frequency rTMS over the contralesional dorsal premotor cortex or low-frequency rTMS over the contralesional primary motor cortex. Low-frequency stimulation over the contralesional primary motor cortex served as an evidence-supported active comparator for poststroke upper limb motor recovery. Stimulation was administered five times per week for two weeks using magnetic resonance imaging-guided neuronavigation. All participants received concurrent standard rehabilitation therapy. The primary outcome was the Fugl-Meyer Assessment for Upper Extremity. Secondary outcomes included the Arm Subscore of the Motricity Index, the Hong Kong version of the Functional Test for the Hemiplegic Upper Extremity, the Modified Barthel Index, and resting-state functional magnetic resonance imaging-derived degree centrality. RESULTS: Both groups showed significant improvements in the primary and secondary behavioral measures (p&#x202f;<&#x202f;0.01), with no significant between-group differences in the magnitude of change (p&#x202f;>&#x202f;0.05). In neuroimaging analyses, patients receiving high-frequency rTMS over the contralesional dorsal premotor cortex showed significantly greater degree centrality changes in the ipsilesional middle occipital gyrus, contralesional medial superior frontal gyrus, and contralesional middle frontal gyrus than those receiving low-frequency rTMS over the contralesional primary motor cortex (p&#x202f;<&#x202f;0.05). Within the high-frequency stimulation group, degree centrality changes in the ipsilesional middle occipital gyrus were positively correlated with improvements in the Fugl-Meyer Assessment for Upper Extremity (r&#x202f;=&#x202f;0.619, false discovery rate-corrected p&#x202f;=&#x202f;0.018). CONCLUSIONS: High-frequency rTMS over the contralesional dorsal premotor cortex produced behavioral improvements comparable to guideline-supported low-frequency rTMS over the contralesional primary motor cortex, without establishing superiority or formal non-inferiority. Exploratory neuroimaging analyses showed greater degree centrality changes in the ipsilesional middle occipital gyrus after high-frequency premotor stimulation, and these changes correlated with upper-limb motor improvement. These findings support further investigation of contralesional dorsal premotor cortex-targeted high-frequency rTMS for severe subacute post-stroke upper limb impairment. REGISTRATION: URL: http://www.chictr.org.cn; Unique identifier: ChiCTR2000038049.

Humans