Atypical gut microbiota composition in a mouse model of developmental stuttering.

Developmental stuttering is a complex neurodevelopmental disorder characterized by disfluent speech. It has been associated with mutations in genes involved in lysosomal enzyme trafficking. Mice with mutations in one such gene, Gnptab, exhibit atypical vocalizations analogous to stuttering in humans. This mouse model has enabled the study of various molecular mechanisms related to the disorder. Simultaneously, an increasing number of reports have suggested the role of gut microbiota in altered brain function and development in neurological disorders. In this study, we compared gut microbiota profiles from Gnptab mutant mice to wildtype control mice. Microbiome analysis demonstrated a distinct microbiota profile in Gnptab mutant mice. The most significant alteration was an increased relative abundance of Akkermansia, a genus of mucin degrading bacteria, which has previously been associated with multiple neurological disorders. Moreover, the altered microbiota profile of these mice was predicted to result in differences in abundance of several metabolic pathways, including short chain fatty acid and lipopolysaccharide synthesis. These pathways may play a role in the onset, progression and persistence of developmental stuttering. This is the first study to show a potential link between developmental stuttering and changes in the gut microbiota, laying the groundwork for a new research direction.

Neuronal and glial cell alterations involved in the retinal degeneration of the familial dysautonomia optic neuropathy.

Familial dysautonomia (FD) is a rare genetic neurodevelopmental and neurodegenerative disorder. In addition to the autonomic and peripheral sensory neuropathies that challenge patient survival, one of the most debilitating symptoms affecting patients' quality of life is progressive blindness resulting from the steady loss of retinal ganglion cells (RGCs). Within the FD community, there is a concerted effort to develop treatments to prevent the loss of RGCs. However, the mechanisms underlying the death of RGCs are not well understood. To study the mechanisms underlying RGC death, Pax6-cre;Elp1loxp/loxp male and female mice and postmortem retinal tissue from an FD patient were used to explore the neuronal and non-neuronal cellular pathology associated with the FD optic neuropathy. Neurons, astrocytes, microglia, Müller glia, and endothelial cells were investigated using a combination of histological analyses. We identified a novel disruption of cellular homeostasis and gliosis in the FD retina. Beginning shortly after birth and progressing with age, the FD retina is marked by astrogliosis and perturbations in microglia, which coincide with vascular remodeling. These changes begin before the onset of RGC death, suggesting alterations in the retinal neurovascular unit may contribute to and exacerbate RGC death. We reveal for the first time that the FD retina pathology includes reactive gliosis, increased microglial recruitment to the ganglion cell layer (GCL), disruptions in the deep and superficial vascular plexuses, and alterations in signaling pathways. These studies implicate the neurovascular unit as a disease-modifying target for therapeutic interventions in FD.

A novel methodology for emotion recognition through 62-lead EEG signals: multilevel heterogeneous recurrence analysis.

Objective: Recognizing emotions from electroencephalography (EEG) signals is a challenging task due to the complex, nonlinear, and nonstationary characteristics of brain activity. Traditional methods often fail to capture these subtle dynamics, while deep learning approaches lack explainability. In this research, we introduce a novel three-phase methodology integrating manifold embedding, multilevel heterogeneous recurrence analysis (MHRA), and ensemble learning to address these limitations in EEG-based emotion recognition. Approach: The proposed methodology was evaluated using the SJTU-SEED IV database. We first applied uniform manifold approximation and projection (UMAP) for manifold embedding of the 62-lead EEG signals into a lower-dimensional space. We then developed MHRA to characterize the complex recurrence dynamics of brain activity across multiple transition levels. Finally, we employed tree-based ensemble learning methods to classify four emotions (neutral, sad, fear, happy) based on the extracted MHRA features. Main results: Our approach achieved high performance, with an accuracy of 0.7885 and an AUC of 0.7552, outperforming existing methods on the same dataset. Additionally, our methodology provided the most consistent recognition performance across different emotions. Sensitivity analysis revealed specific MHRA metrics that were strongly associated with each emotion, offering valuable insights into the underlying neural dynamics. Significance: This study presents a novel framework for EEG-based emotion recognition that effectively captures the complex nonlinear and nonstationary dynamics of brain activity while maintaining explainability. The proposed methodology offers significant potential for advancing our understanding of emotional processing and developing more reliable emotion recognition systems with broad applications in healthcare and beyond.

CNTools: A computational toolbox for cellular neighborhood analysis from multiplexed images.

Recent studies show that cellular neighborhoods play an important role in evolving biological events such as cancer and diabetes. Therefore, it is critical to accurately and efficiently identify cellular neighborhoods from spatially-resolved single-cell transcriptomic data or single-cell resolution tissue imaging data. In this work, we develop CNTools, a computational toolbox for end-to-end cellular neighborhood analysis on annotated cell images, comprising both the identification and analysis steps. It includes state-of-the-art cellular neighborhood identification methods and post-identification smoothing techniques, with our newly proposed Cellular Neighbor Embedding (CNE) method and Naive Smoothing technique, as well as several established downstream analysis approaches. We applied CNTools on three real-world CODEX datasets and evaluated identification methods with smoothing techniques quantitatively and qualitatively. It shows that CNE with Naive Smoothing overall outperformed other methods and revealed more convincing biological insights. We also provided suggestions on how to choose proper identification methods and smoothing techniques according to input data.

Abdominal MR Multitasking for radiotherapy treatment planning: A motion-resolved and multicontrast 3D imaging approach.

PURPOSE: Radiotherapy treatment planning (RTP) using MR has been used increasingly for the abdominal site. Multiple contrast weightings and motion-resolved imaging are desired for accurate delineation of the target and various organs-at-risk and patient-tailored planning. Current MR protocols achieve these through multiple scans with distinct contrast and variable respiratory motion management strategies and acquisition parameters, leading to a complex and inaccurate planning process. This study presents a standalone MR Multitasking (MT)-based technique to produce volumetric, motion-resolved, multicontrast images for abdominal radiotherapy treatment planning. METHODS: The MT technique resolves motion and provides a wide range of contrast weightings by repeating a magnetization-prepared (saturation recovery and T2 preparations) spoiled gradient-echo readout series and adopting the MT image reconstruction framework. The performance of the technique was assessed through digital phantom simulations and in vivo studies of both healthy volunteers and patients with liver tumors. RESULTS: In the digital phantom study, the MT technique presented structural details and motion in excellent agreement with the digital ground truth. The in vivo studies showed that the motion range was highly correlated (R2 = 0.82) between MT and 2D cine imaging. MT allowed for a flexible contrast-weighting selection for better visualization. Initial clinical testing with interobserver analysis demonstrated acceptable target delineation quality (Dice coefficient = 0.85 ± 0.05, Hausdorff distance = 3.3 ± 0.72 mm). CONCLUSION: The developed MT-based, abdomen-dedicated technique is capable of providing motion-resolved, multicontrast volumetric images in a single scan, which may facilitate abdominal radiotherapy treatment planning.

The impact of widowhood on mental health: anxiety, depression, and stress among widowed women in Nepal.

Introduction: In South Asia, particularly in regions with strong patriarchal norms, widowhood is stigmatized, compounding the negative impact of grief and partner loss. This study measured the prevalence of mental health symptoms among widows in Nepal and its relationship to demographic variables. Methods: This cross-sectional study surveyed 588 Nepalese widows from six districts in Nepal (mean age = 52.62, SD = 13.99) who had lost their spouses within the past two years. Participants completed the Anxiety, Depression and Stress Scale (ADSS). Analyses examined prevalence of anxiety, depression, and stress symptoms, using standard ADSS cut-points. Level of anxiety, depression, and stress symptoms measured by the ADSS in the sample were also compared with female psychiatric and nonpsychiatric normative ADSS data, and were compared with one available comparison sample (a sample of older Nepalese women). Measures of association between ADSS scores and demographic variables were computed. Results: Results showed that a high percentage of the Nepalese widows reported moderate to severe symptoms of anxiety, depression, and stress. They also endorsed significantly higher levels of anxiety, depression, and stress symptoms relative to normative data and the comparison sample. Stress scores were significantly negatively correlated with age, Anxiety and Depression scores were associated with income under the poverty line, and Depression scores were associated with homemaker status. Discussion: These findings confirm the high emotional distress among widowed women in Nepal, and establish the relationship between emotional distress and poverty, homemaker status, and age. These findings can inform public health efforts and mental health care providers regarding the mental health needs of widows in Nepal.

The lowdown on breakdown: Open questions in plant proteolysis.

Proteolysis, including post-translational proteolytic processing as well as protein degradation and amino acid recycling, is an essential component of the growth and development of living organisms. In this article, experts in plant proteolysis pose and discuss compelling open questions in their areas of research. Topics covered include the role of proteolysis in the cell cycle, DNA damage response, mitochondrial function, the generation of N-terminal signals (degrons) that mark many proteins for degradation (N-terminal acetylation, the Arg/N-degron pathway, and the chloroplast N-degron pathway), developmental and metabolic signaling (photomorphogenesis, abscisic acid and strigolactone signaling, sugar metabolism, and postharvest regulation), plant responses to environmental signals (endoplasmic-reticulum-associated degradation, chloroplast-associated degradation, drought tolerance, and the growth-defense trade-off), and the functional diversification of peptidases. We hope these thought-provoking discussions help to stimulate further research.

Hydroxyurea to prevent brain injury in children with sickle cell disease (HU Prevent)-A randomized, placebo-controlled phase II feasibility/pilot study.

Central nervous system (CNS) injury is common in sickle cell disease (SCD) and occurs early in life. Hydroxyurea is safe and efficacious for treatment of SCD, but high-quality evidence from randomized trials to estimate its neuroprotective effect is scant. HU Prevent was a randomized (1:1), double-blind, phase II feasibility/pilot trial of dose-escalated hydroxyurea vs. placebo for the primary prevention of CNS injury in children with HbSS or HbS-ß0-thalassemia subtypes of SCD age 12-48 months with normal neurological examination, MRI of the brain, and cerebral blood flow velocity. We hypothesized that hydroxyurea would reduce by 50% the incidence of CNS injury. Two outcomes were compared: primary-a composite of silent cerebral infarction, elevated cerebral blood flow velocity, transient ischemic attack, or stroke; secondary-a weighted score estimating the risk of suffering the consequences of stroke (the Stroke Consequences Risk Score-SCRS), based on the same outcome events. Six participants were randomized to each group. One participant in the hydroxyurea group had a primary outcome vs. four in the placebo group (incidence rate ratio [90% CI] 0.216 [0.009, 1.66], p = .2914) (~80% reduction in the hydroxyurea group). The mean SCRS score was 0.078 (SD 0.174) in the hydroxyurea group, 0.312 (SD 0.174) in the placebo group, p = .072, below the p-value of .10 often used to justify subsequent phase III investigations. Serious adverse events related to study procedures occurred in 3/41 MRIs performed, all related to sedation. These results suggest that hydroxyurea may have profound neuroprotective effect in children with SCD and support a definitive phase III study to encourage the early use of hydroxyurea in all infants with SCD.

CD39 delineates chimeric antigen receptor regulatory T cell subsets with distinct cytotoxic & regulatory functions against human islets.

Human regulatory T cells (Treg) suppress other immune cells. Their dysfunction contributes to the pathophysiology of autoimmune diseases, including type 1 diabetes (T1D). Infusion of Tregs is being clinically evaluated as a novel way to prevent or treat T1D. Genetic modification of Tregs, most notably through the introduction of a chimeric antigen receptor (CAR) targeting Tregs to pancreatic islets, may improve their efficacy. We evaluated CAR targeting of human Tregs to monocytes, a human ß cell line and human islet ß cells in vitro. Targeting of HLA-A2-CAR (A2-CAR) bulk Tregs to HLA-A2+ cells resulted in dichotomous cytotoxic killing of human monocytes and islet ß cells. In exploring subsets and mechanisms that may explain this pattern, we found that CD39 expression segregated CAR Treg cytotoxicity. CAR Tregs from individuals with more CD39low/- Tregs and from individuals with genetic polymorphism associated with lower CD39 expression (rs10748643) had more cytotoxicity. Isolated CD39- CAR Tregs had elevated granzyme B expression and cytotoxicity compared to the CD39+ CAR Treg subset. Genetic overexpression of CD39 in CD39low CAR Tregs reduced their cytotoxicity. Importantly, ß cells upregulated protein surface expression of PD-L1 and PD-L2 in response to A2-CAR Tregs. Blockade of PD-L1/PD-L2 increased ß cell death in A2-CAR Treg co-cultures suggesting that the PD-1/PD-L1 pathway is important in protecting islet ß cells in the setting of CAR immunotherapy. In summary, introduction of CAR can enhance biological differences in subsets of Tregs. CD39+ Tregs represent a safer choice for CAR Treg therapies targeting tissues for tolerance induction.

Older Adults with Cancer and Common Comorbidities-Challenges and Opportunities in Improving Their Cancer Treatment Outcomes.

The older American population is rapidly increasing, and millions of older adults will be cancer survivors with comorbidities. This population faces specific challenges regarding treatment and has unique clinical needs. Recognizing this need, the National Cancer Institute (NCI), in collaboration with the National Institute on Aging (NIA), hosted a webinar series, entitled "Cancer, Aging, and Comorbidities." This commentary provides a reflection of five thematic areas covered by the webinar series, which was focused on improving cancer treatment for older adults with cancer and comorbidities: i) the impact of comorbidities on treatment tolerability and patient outcomes; ii) the impact of comorbidities on cancer clinical trial design; iii) the development of wearable devices in measuring comorbidities in cancer treatment; iv) the effects of nutrition and the microbiome on cancer therapy and; v) the role of senescence and senotherapy in age-related diseases. While advances have been made in these areas, many gaps and challenges exist and are discussed in this commentary. To improve cancer survivorship in older populations with comorbidities, aging and comorbidities must be jointly considered and incorporated across the spectrum of cancer research. This includes more basic research of the mechanisms linking comorbidities and cancer development and treatment response, building critical resources and infrastructure (eg, preclinical models and patient samples), conducting clinical trials focused on the older population, integrating geriatric assessment into cancer treatment, and incorporating novel technologies, such as wearable devices into clinical trials and cancer care.

Orthotopic Models Using New, Murine Lung Adenocarcinoma Cell Lines Simulate Human Non-Small Cell Lung Cancer Treated with Immunotherapy.

Understanding tumor-host immune interactions and the mechanisms of lung cancer response to immunotherapy is crucial. Current preclinical models used to study this often fall short of capturing the complexities of human lung cancer and lead to inconclusive results. To bridge the gap, we introduce two new murine monoclonal lung cancer cell lines for use in immunocompetent orthotopic models. We demonstrate how our cell lines exhibit immunohistochemical protein expression (TTF-1, NapA, PD-L1) and common driver mutations (KRAS, p53, and p110α) seen in human lung adenocarcinoma patients, and how our orthotopic models respond to combination immunotherapy in vivo in a way that closely mirrors current clinical outcomes. These new lung adenocarcinoma cell lines provide an invaluable, clinically relevant platform for investigating the intricate dynamics between tumor and the immune system, and thus potentially contributes to a deeper understanding of immunotherapeutic approaches to lung cancer treatment.

Dietary Quality and Diet-Related Factors Among Emerging Adults (18-23 y) in the United States Are a Cause for Concern: National Health and Nutrition Examination Survey 2015-2018.

BACKGROUND: Poor dietary quality is a risk factor for diet-related chronic disease and suboptimal nutritional patterns often begin early in the life course. Although the dietary intakes of young children, adolescents, and middle-aged and older adults are well established, much less is known about emerging adults, who represent a unique time point in life, as they are undergoing significant changes in food environments, autonomy, finances, and caregiver and parental involvement. OBJECTIVES: This study aimed to examine dietary quality, as assessed via the Healthy Eating Index (HEI), by demographic, socioeconomic, and health-related characteristics among emerging adults (18-23 y) in the United States who participated in the 2015-2018 National Health and Nutrition Examination Survey (NHANES). METHODS: NHANES data were collected via a household interview and 2 24-h dietary recalls (24HR). Usual dietary intakes from the 24HRs were approximated using the multivariate National Cancer Institute Method to compute mean HEI-2015 overall and component scores (range: 0-100; higher scores indicating higher dietary quality). RESULTS: Overall dietary quality among emerging adults (HEI-2015: 50.3 ± 1.3) was significantly lower than other adults (≥24 y) (HEI-2015: 56.3 ± 0.5; P < 0.0001) in the United States, with differences primarily driven by lower intakes of whole fruit, vegetables, and whole grains and higher intakes of sodium, refined grains, and saturated fat. Few differences in HEI-2015 scores were noted across population subgroups by sex, food security, family income, and food assistance program participation, except for added sugar; intakes of added sugar were significantly higher among women, food insecure, and food assistance program participants than those in their counterparts, respectively. CONCLUSIONS: Dietary quality is poor among emerging adults in the United States and persists across all population subgroups, suggesting a significant need for tailored public health interventions to improve dietary quality among this population. Future research investigating to what extent emerging adults prioritize healthful behaviors and exploring other indicators for identifying nutritionally vulnerable subgroups may be impactful for identifying disparities among this life stage.

Unexpected roles for AMPK in the suppression of autophagy and the reactivation of MTORC1 signaling during prolonged amino acid deprivation.

AMPK promotes catabolic and suppresses anabolic cell metabolism to promote cell survival during energetic stress, in part by inhibiting MTORC1, an anabolic kinase requiring sufficient levels of amino acids. We found that cells lacking AMPK displayed increased apoptotic cell death during nutrient stress caused by prolonged amino acid deprivation. We presumed that impaired macroautophagy/autophagy explained this phenotype, as a prevailing view posits that AMPK initiates autophagy (often a pro-survival response) through phosphorylation of ULK1. Unexpectedly, however, autophagy remained unimpaired in cells lacking AMPK, as monitored by several autophagic readouts in several cell lines. More surprisingly, the absence of AMPK increased ULK1 signaling and MAP1LC3B/LC3B lipidation during amino acid deprivation while AMPK-mediated phosphorylation of ULK1 S555 (a site proposed to initiate autophagy) decreased upon amino acid withdrawal or pharmacological MTORC1 inhibition. In addition, activation of AMPK with compound 991, glucose deprivation, or AICAR blunted autophagy induced by amino acid withdrawal. These results demonstrate that AMPK activation and glucose deprivation suppress autophagy. As AMPK controlled autophagy in an unexpected direction, we examined how AMPK controls MTORC1 signaling. Paradoxically, we observed impaired reactivation of MTORC1 in cells lacking AMPK upon prolonged amino acid deprivation. Together these results oppose established views that AMPK promotes autophagy and inhibits MTORC1 universally. Moreover, they reveal unexpected roles for AMPK in the suppression of autophagy and the support of MTORC1 signaling in the context of prolonged amino acid deprivation. These findings prompt a reevaluation of how AMPK and its control of autophagy and MTORC1 affect health and disease.

Nutritional Beliefs and Practices of Arabic-Speaking Middle Eastern Mothers Living in the United States.

INTRODUCTION: Culture and acculturation influence nutritional beliefs. Little is known about the Arabic population in the United States. In this study, Arabic-speaking Middle Eastern mothers' perceptions of motherhood and childhood nutritional beliefs and practices are explored. METHOD: Semi-structured interviews with 12 mothers from Arabic-speaking Middle Eastern countries. RESULTS: Food and family are central to everyday life. Mothers worked hard to maintain traditional nutritional practices with their school-age children. DISCUSSION: Findings can enhance school nurses' ability to collaborate with mothers in nutritional education and address any issues in the classroom.

AnnoSpat annotates cell types and quantifies cellular arrangements from spatial proteomics.

Cellular composition and anatomical organization influence normal and aberrant organ functions. Emerging spatial single-cell proteomic assays such as Image Mass Cytometry (IMC) and Co-Detection by Indexing (CODEX) have facilitated the study of cellular composition and organization by enabling high-throughput measurement of cells and their localization directly in intact tissues. However, annotation of cell types and quantification of their relative localization in tissues remain challenging. To address these unmet needs for atlas-scale datasets like Human Pancreas Analysis Program (HPAP), we develop AnnoSpat (Annotator and Spatial Pattern Finder) that uses neural network and point process algorithms to automatically identify cell types and quantify cell-cell proximity relationships. Our study of data from IMC and CODEX shows the higher performance of AnnoSpat in rapid and accurate annotation of cell types compared to alternative approaches. Moreover, the application of AnnoSpat to type 1 diabetic, non-diabetic autoantibody-positive, and non-diabetic organ donor cohorts recapitulates known islet pathobiology and shows differential dynamics of pancreatic polypeptide (PP) cell abundance and CD8+ T cells infiltration in islets during type 1 diabetes progression.

Exploring Cultural Competence, Inclusivity, and Diversity in Ketamine Assisted Psychotherapy: A Phenomenological Study.

Black, Indigenous, and People of Color (BIPOC), and other minoritized populations are insufficiently represented in research on therapeutic psychedelics. This research was a phenomenological qualitative exploration of a culturally diverse (Hispanic, African American, Asian, Native American, biracial, or LGBTQIA+) and low-income sample of 15 individuals receiving ketamine-assisted psychotherapy (KAP) at a sliding-scale fee community clinic. Participants were interviewed after a ketamine session, after a ketamine integration session, and one month later. The interviews inquired about mental and emotional state prior to treatment and the treatment context (traditionally called set and setting), preparation for treatment, experiences during the ketamine and integration sessions, barriers to treatment, perceived stigma if any, reflections on KAPs' impact, and relevance of culture to the treatment. The current analysis, which focuses on participant comments related to diversity, equity, and inclusion that are uniquely relevant to this sample and the research goals, yielded four major themes: Insufficient Financial Resources, Race, Ethnicity, and LGBTQIA+, Stigma, and Culture and Ritual. Themes and subthemes are presented accompanied by representative quotes. Results demonstrate the high salience of culture in the KAP experience and the need to incorporate issues of race, culture, stigma, ritual, and socioeconomic status into treatment planning and outcome research.

Enhancing Implementation of the I-PASS Handoff Tool Using a Provider Handoff Task Force at a Comprehensive Cancer Center.

BACKGROUND: Communication failures are among the most common causes of harmful medical errors. At one Comprehensive Cancer Center, patient handoffs varied among services. The authors describe the implementation and results of an organization-wide project to improve handoffs and implement an evidence-based handoff tool across all inpatient services. METHODS: The research team created a task force composed of members from 22 hospital services-advanced practice providers (APPs), trainees, some faculty members, electronic health record (EHR) staff, education and training specialists, and nocturnal providers. Over two years, the task force expanded to include consulting services and Anesthesiology. Factors contributing to ineffective handoffs were identified and organized into categories. The EHR I-PASS tool was used to standardize handoff documentation. Training was provided to staff on its use, and compliance was monitored using a customized dashboard. I-PASS champions in each service were responsible for the rollout of I-PASS in their respective services. The data were reported quarterly to the Quality Assessment and Performance Improvement (QAPI) governing committee. Provider handoff perception was assessed through the biennial Institution-wide safety culture survey. RESULTS: All fellows, residents, APPs, and physician assistants were trained in the use of I-PASS, either online or in person. Adherence to the I-PASS written tool improved from 41.6% in 2019 to 70.5% in 2022 (p < 0.05), with improvements seen in most services. The frequency of updating I-PASS elements and the action list in the handoff tool also increased over time. The handoff favorability score on the safety culture survey improved from 38% in 2018 to 59% in 2022. CONCLUSION: The implementation approach developed by the Provider Handoff Task Force led to increased use of the I-PASS EHR tool and improved safety culture survey handoff favorability.

Roadmap for the next decade of plant programmed cell death research.

Programmed cell death (PCD) is fundamentally important for plant development, abiotic stress responses and immunity, but our understanding of its regulation remains fragmented. Building a stronger research community is required to accelerate progress in this area through knowledge exchange and constructive debate. In this Viewpoint, we aim to initiate a collective effort to integrate data across a diverse set of experimental models to facilitate characterisation of the fundamental mechanisms underlying plant PCD and ultimately aid the development of a new plant cell death classification system in the future. We also put forward our vision for the next decade of plant PCD research stemming from discussions held during the 31st New Phytologist workshop, 'The Life and Death Decisions of Plant Cells' that took place at University College Dublin in Ireland (14-15 June 2023). We convey the key areas of significant progress and possible future research directions identified, including resolving the spatiotemporal control of cell death, isolation of its molecular and genetic regulators, and harnessing technical advances for studying PCD events in plants. Further, we review the breadth of potential impacts of plant PCD research and highlight the promising new applications of findings from this dynamically evolving field.

Distinct ancient structural polymorphisms control heterodichogamy in walnuts and hickories.

The maintenance of stable mating type polymorphisms is a classic example of balancing selection, underlying the nearly ubiquitous 50/50 sex ratio in species with separate sexes. One lesser known but intriguing example of a balanced mating polymorphism in angiosperms is heterodichogamy - polymorphism for opposing directions of dichogamy (temporal separation of male and female function in hermaphrodites) within a flowering season. This mating system is common throughout Juglandaceae, the family that includes globally important and iconic nut and timber crops - walnuts (Juglans), as well as pecan and other hickories (Carya). In both genera, heterodichogamy is controlled by a single dominant allele. We fine-map the locus in each genus, and find two ancient (>50 Mya) structural variants involving different genes that both segregate as genus-wide trans-species polymorphisms. The Juglans locus maps to a ca. 20 kb structural variant adjacent to a probable trehalose phosphate phosphatase (TPPD-1), homologs of which regulate floral development in model systems. TPPD-1 is differentially expressed between morphs in developing male flowers, with increased allele-specific expression of the dominant haplotype copy. Across species, the dominant haplotype contains a tandem array of duplicated sequence motifs, part of which is an inverted copy of the TPPD-1 3' UTR. These repeats generate various distinct small RNAs matching sequences within the 3' UTR and further downstream. In contrast to the single-gene Juglans locus, the Carya heterodichogamy locus maps to a ca. 200-450 kb cluster of tightly linked polymorphisms across 20 genes, some of which have known roles in flowering and are differentially expressed between morphs in developing flowers. The dominant haplotype in pecan, which is nearly always heterozygous and appears to rarely recombine, shows markedly reduced genetic diversity and is over twice as long as its recessive counterpart due to accumulation of various types of transposable elements. We did not detect either genetic system in other heterodichogamous genera within Juglandaceae, suggesting that additional genetic systems for heterodichogamy may yet remain undiscovered.