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1.
J Transcult Nurs ; : 10436596241286232, 2024 Sep 30.
Artigo em Inglês | MEDLINE | ID: mdl-39350494

RESUMO

INTRODUCTION: We aimed to describe the health and well-being of family caregivers of Native Hawaiian and Pacific Islander (NHPI) adults living with Alzheimer's disease and related dementias (ADRD), explore cultural values related to caregiving, and characterize barriers and facilitators to their health and well-being. METHODOLOGY: Caregivers of NHPIs living with ADRD were recruited from across the United States to complete a multimethod study including a survey followed by an interview about their health and well-being. RESULTS: Eleven participants completed surveys, six of whom completed an interview. Themes included caring as a community, lokahi (balance), and the importance of sleep, food, and physical activity. Cultural values included connection to cultural practices, kupuna (elders) as cultural knowledge holders, and the kuleana (responsibility) of caregiving. DISCUSSION: Caregiving for an NHPI adult living with ADRD occurs beyond the dyad, and is a matter of family and community. Culturally-based interventions offered through community and healthcare organizations may be critical to promoting caregiver health.

2.
Chest ; 166(3): e75-e77, 2024 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-39260949

RESUMO

Chylothorax, which accounts for 1% to 3% of pleural effusions, typically results from either surgery (traumatic) or underlying malignancy (nontraumatic). Less common causes of nontraumatic chylothorax are numerous and include congenital lymphatic abnormalities, connective tissue diseases, cirrhosis, and infection, among others.1 We describe what appears to be the first reported case of chylothorax caused by chylous ascites in Crohn disease. This case highlights the importance of using diagnostic evidence to link new symptoms to preexisting diseases whenever possible, as well as the systemic nature of Crohn disease.


Assuntos
Quilotórax , Doença de Crohn , Humanos , Doença de Crohn/complicações , Doença de Crohn/diagnóstico , Quilotórax/etiologia , Quilotórax/diagnóstico , Feminino , Ascite Quilosa/etiologia , Ascite Quilosa/diagnóstico , Adulto , Tomografia Computadorizada por Raios X
3.
Chembiochem ; : e202400578, 2024 Sep 06.
Artigo em Inglês | MEDLINE | ID: mdl-39239825

RESUMO

Methods for modifying intact peptides are useful but can be unselective with regard to amino acid position and sequence context. In this work, we used in vitro selection to identify DNAzymes that acylate a Lys residue of a short peptide in sequence-dependent fashion. The DNAzymes do not acylate Lys when placed at other residues in the peptide, and the acylation activity depends on the Lys sequence context. A good acylation yield is observed on the preparative nanomole scale. These findings are promising for further development of DNAzymes for broader application to top-down Lys acylation of peptide and protein substrates.

4.
Artigo em Inglês | MEDLINE | ID: mdl-39264428

RESUMO

PURPOSE: Postinjury multiple organ failure (MOF) is the sequela to the disease of polytrauma. We aimed to describe the contemporary population-based epidemiology of MOF within a mature trauma system, to analyse the time taken for MOF to develop, and to evaluate the temporal patterns and contributions of the individual constituent organ failures. METHODS: Prospective observational study conducted across five Level-1 trauma centers in New South Wales, Australia. Trauma patients at-risk of MOF (Denver > 3 from 48 h post-admission), aged > 16 years, ISS > 15, and who stayed in ICU for ≥ 48 h were eligible for inclusion. RESULTS: From May 2018-February 2021, 600 at-risk polytrauma patients were prospectively enrolled (mean(SD)age = 49(21)years, males = 453/600(76%),median(IQR)ISS = 26(20,34)). MOF incidence was 136/600(23%) among at-risk patients, 142/6248(2%) among major trauma patients (ISS > 12 per Australian definition), and 0.8/100,000 in the general population. The mortality rate was 55/600(11%) in the overall study population, and 34/136(25%) in MOF patients. 82/136(60%) of MOF patients developed MOF on day-3. No patients developed MOF after day-13. Among MOF patients, 60/136(44%) had cardiac failures (mortality = 37%), 39/136(29%) had respiratory failures (mortality = 23%), 24/136(18%) had renal failures (mortality = 63%), and 12/136(9%) had hepatic failures (mortality = 50%). CONCLUSION: Although a rare syndrome in the general population, MOF occurred in 23% of the most severely injured polytrauma patients. When compared to previous risk-matched cohorts, MOF become more common, but not more lethal, despite a decade older cohort. The heart has superseded the lungs as the most common organ to fail. Cardiac and respiratory failures occurred earlier and were associated with lower mortality than renal and hepatic failures.

5.
Artigo em Inglês | MEDLINE | ID: mdl-39327857

RESUMO

BACKGROUND: In two phase 3 studies, tenofovir alafenamide (TAF) showed non-inferior efficacy versus tenofovir disoproxil fumarate (TDF), with more favourable renal and bone safety in patients with chronic hepatitis B (CHB). AIMS: Here, we report the studies' final 8-year results. METHODS: CHB patients (hepatitis B e antigen [HBeAg]-negative and HBeAg-positive) were randomised (2:1) to double-blind TAF 25 mg/day or TDF 300 mg/day for up to 3 years, followed by open-label (OL) TAF through year 8. Virological, biochemical, serological and fibrosis responses, and safety, including bone and renal parameters, were evaluated. Resistance to TAF was assessed annually by deep sequencing of polymerase/reverse transcriptase and by phenotyping. RESULTS: Among 1298 patients randomised to double-blind TAF (n = 866) or double-blind TDF (n = 432), 775 in the TAF group and 382 in the TDF group received OL TAF, including 180 and 202 who switched from TDF to TAF at year 2 (TDF2y → TAF6y) or year 3 (TDF3y → TAF5y), respectively. At year 8, among patients in the TAF8y, TDF2y → TAF6y and TDF3y → TAF5y groups, 69%, 66% and 73% (missing-equals-failure analysis) and 95%, 94% and 97% (missing-equals-excluded) of patients, respectively, achieved HBV DNA <29 IU/mL. Estimated glomerular filtration rate (Cockcroft-Gault method; eGFRCG) and hip/spine bone mineral density (BMD) remained stable in patients receiving double-blind/OL TAF, with only small declines at year 8. Decreases in eGFRCG and hip/spine BMD observed during double-blind TDF improved after switching to OL TAF. No patients developed resistance to TAF. CONCLUSION: Long-term TAF treatment exhibited favourable safety and tolerability with high rates of viral suppression and no development of resistance. CLINICALTRIALS: gov numbers NCT01940341 and NCT01940471.

6.
JAMA Netw Open ; 7(9): e2429454, 2024 Sep 03.
Artigo em Inglês | MEDLINE | ID: mdl-39287949

RESUMO

Importance: Since 2014, Medicaid expansion has been implemented in many states across the US, increasing health care access among vulnerable populations, including formerly incarcerated people who experience higher mortality rates than the general population. Objective: To examine population-level association of Medicaid expansion with postrelease mortality from all causes, unintentional drug overdoses, opioid overdoses, polydrug overdoses, suicides, and homicides among formerly incarcerated people in Rhode Island (RI), which expanded Medicaid, compared with North Carolina (NC), which did not expand Medicaid during the study period. Design, Setting, and Participants: A cohort study was conducted using incarceration release data from January 1, 2009, to December 31, 2018, linked to death records from January 1, 2009, to December 31, 2019, on individuals released from incarceration in RI and NC. Data analysis was performed from August 20, 2022, to February 15, 2024. Participants included those aged 18 years or older who were released from incarceration. Individuals who were temporarily held during ongoing judicial proceedings, died during incarceration, or not released from incarceration during the study period were excluded. Exposure: Full Medicaid expansion in RI effective January 1, 2014. Main Outcomes and Measures: Mortality from all causes, unintentional drug overdoses, unintentional opioid and polydrug overdoses, suicides, and homicides. Results: Between 2009 and 2018, 17 824 individuals were released from RI prisons (mean [SD] age, 38.39 [10.85] years; 31 512 [89.1%] male) and 160 861 were released from NC prisons (mean [SD] age, 38.28 [10.84] years; 209 021 [87.5%] male). Compared with NC, people who were formerly incarcerated in RI experienced a sustained decrease of 72 per 100 000 person-years (95% CI, -108 to -36 per 100 000 person-years) in all-cause mortality per quarter after Medicaid expansion. Similar decreases were observed in RI in drug overdose deaths (-172 per 100 000 person-years per 6 months; 95% CI, -226 to -117 per 100 000 person-years), including opioid and polydrug overdoses, and homicide deaths (-23 per 100 000 person-years per year; 95% CI, -50 to 4 per 100 000 person-years) after Medicaid expansion. Suicide mortality did not change after Medicaid expansion. After Medicaid expansion in RI, non-Hispanic White individuals experienced 3 times greater sustained decreases in all-cause mortality than all racially minoritized individuals combined, while non-Hispanic Black individuals did not experience any substantial benefits. There was no modification by sex. Individuals aged 30 years or older experienced greater all-cause mortality reduction after Medicaid expansion than those younger than 30 years. Conclusions and Relevance: Medicaid expansion in RI was associated with a decrease in all-cause, overdose, and homicide mortality among formerly incarcerated people. However, these decreases were most observed among White individuals, while racially minoritized individuals received little to no benefits in the studied outcomes.


Assuntos
Overdose de Drogas , Medicaid , Prisioneiros , Humanos , Medicaid/estatística & dados numéricos , Masculino , Feminino , Estados Unidos/epidemiologia , Prisioneiros/estatística & dados numéricos , Adulto , North Carolina/epidemiologia , Pessoa de Meia-Idade , Overdose de Drogas/mortalidade , Rhode Island/epidemiologia , Estudos de Coortes , Homicídio/estatística & dados numéricos , Mortalidade/tendências , Adulto Jovem , Suicídio/estatística & dados numéricos , Causas de Morte/tendências
7.
Reprod Toxicol ; : 108720, 2024 Sep 19.
Artigo em Inglês | MEDLINE | ID: mdl-39306261

RESUMO

Ethanol is one of the most common teratogens and causes of human developmental disabilities. Fetal alcohol spectrum disorders (FASD), which describes the wide range of deficits due to prenatal ethanol exposure, are estimated to affect between 1.1% to 5.0% of births in the United States. Ethanol dysregulates numerous cellular mechanisms such as programmed cell death (apoptosis), protein synthesis, autophagy, and various aspects of cell signaling, all of which contribute to FASD. The mechanistic target of rapamycin (mTOR) regulates these cellular mechanisms via sensing of nutrients like amino acids and glucose, DNA damage, and growth factor signaling. Despite an extensive literature on ethanol teratogenesis and mTOR signaling, there has been less attention paid to their interaction. Here, we discuss the impact of ethanol teratogenesis on mTORC1's ability to coordinate growth factor and amino acid sensing with protein synthesis, autophagy, and apoptosis. Notably, the effect of ethanol exposure on mTOR signaling depends on the timing and dose of ethanol as well as the system studied. Overall, the overlap between the functions of mTORC1 and the phenotypes observed in FASD suggest a mechanistic interaction. However, more work is required to fully understand the impact of ethanol teratogenesis on mTOR signaling.

8.
Benef Microbes ; : 1-16, 2024 Sep 23.
Artigo em Inglês | MEDLINE | ID: mdl-39322223

RESUMO

Obesity is a risk factor for cardio-metabolic and neurological disease. The contribution of gut microbiota to derangements of the gut-brain axis in the context of obesity has been acknowledged, particularly through physiology modulation by short-chain fatty acids (SCFAs). Thus, probiotic interventions and administration of SCFAs have been employed with the purpose of alleviating symptoms in both metabolic and neurological disease. We investigated the effects of four butyrate-producing bacteria from the Lachnospiraceae family on the development of metabolic syndrome and behavioural alterations in a mouse model of diet-induced obesity. Male mice were fed either a high-fat diet (HFD) or an ingredient-matched control diet for 2 months, and bacteria cultures or culture medium were given by gavage to HFD-fed mice every second day. Mice were assessed through a battery of metabolic and behaviour tests, and fluxes through the gut barrier and blood-brain barrier were determined using Dextran-based tracers. One of the administered bacteria from the Coprococcus genus, which produces butyrate and formate, afforded some degree of protection against the development of obesity and its complications. Results from this study, however, are insufficient to support brain health benefits of the bacteria tested. None of the bacteria modulated permeability through the gut or blood-brain barriers. Our results suggest health benefits of a bacteria from Lachnospiraceae family, and encourage further exploration of its use as probiotic.

9.
Cell Rep ; 43(9): 114676, 2024 Sep 24.
Artigo em Inglês | MEDLINE | ID: mdl-39217614

RESUMO

Obesity and fatty liver diseases-metabolic dysfunction-associated steatotic liver disease (MASLD) and metabolic dysfunction-associated steatohepatitis (MASH)-affect over one-third of the global population and are exacerbated in individuals with reduced functional aldehyde dehydrogenase 2 (ALDH2), observed in approximately 560 million people. Current treatment to prevent disease progression to cancer remains inadequate, requiring innovative approaches. We observe that Aldh2-/- and Aldh2-/-Sptbn1+/- mice develop phenotypes of human metabolic syndrome (MetS) and MASH with accumulation of endogenous aldehydes such as 4-hydroxynonenal (4-HNE). Mechanistic studies demonstrate aberrant transforming growth factor ß (TGF-ß) signaling through 4-HNE modification of the SMAD3 adaptor SPTBN1 (ß2-spectrin) to pro-fibrotic and pro-oncogenic phenotypes, which is restored to normal SMAD3 signaling by targeting SPTBN1 with small interfering RNA (siRNA). Significantly, therapeutic inhibition of SPTBN1 blocks MASH and fibrosis in a human model and, additionally, improves glucose handling in Aldh2-/- and Aldh2-/-Sptbn1+/- mice. This study identifies SPTBN1 as a critical regulator of the functional phenotype of toxic aldehyde-induced MASH and a potential therapeutic target.


Assuntos
Aldeído-Desidrogenase Mitocondrial , Aldeídos , Neoplasias , Obesidade , Transdução de Sinais , Proteína Smad3 , Fator de Crescimento Transformador beta , Animais , Humanos , Fator de Crescimento Transformador beta/metabolismo , Aldeídos/metabolismo , Obesidade/metabolismo , Obesidade/patologia , Camundongos , Aldeído-Desidrogenase Mitocondrial/metabolismo , Aldeído-Desidrogenase Mitocondrial/genética , Proteína Smad3/metabolismo , Neoplasias/metabolismo , Neoplasias/patologia , Neoplasias/genética , Espectrina/metabolismo , Espectrina/genética , Camundongos Endogâmicos C57BL , Masculino , Camundongos Knockout , Síndrome Metabólica/metabolismo , Síndrome Metabólica/patologia , Síndrome Metabólica/genética
10.
Artigo em Inglês | MEDLINE | ID: mdl-39338132

RESUMO

Native Hawaiian and Pacific Islanders (NHPIs) are overrepresented in Hawai'i's houseless population. Indigenous populations, such as NHPIs, may encounter experiences of historical trauma that impact their well-being. This original research project examines how NHPI identity and houselessness compound to affect the perceived stress and historical trauma of transition-aged youth. Fifty-one participants aged 18 to 24 (M = 21.37, SD = 1.93) completed a survey that included the historical traumatic events scale, historical loss scale, perceived stress scale, and a demographic questionnaire. Over half (n = 26, 51.0%) of the participants identified as NHPI. A two-way ANOVA indicated a non-significant effect of NHPI identity and housing status on perceived stress. However, housed participants scored significantly higher than participants experiencing houselessness on the historical traumatic events scale (p = 0.006). Our findings elucidate the role of knowledge in the experience of historical trauma. Further results, limitations, and future directions are offered.


Assuntos
Habitação , Havaiano Nativo ou Outro Ilhéu do Pacífico , Estresse Psicológico , Humanos , Havaiano Nativo ou Outro Ilhéu do Pacífico/psicologia , Feminino , Masculino , Havaí , Estresse Psicológico/psicologia , Adulto Jovem , Adolescente , Trauma Histórico/psicologia , Inquéritos e Questionários , Adulto , População das Ilhas do Pacífico
11.
J Physiol ; 2024 Aug 31.
Artigo em Inglês | MEDLINE | ID: mdl-39216087

RESUMO

Mechanical ventilation (MV) is used to support ventilation and pulmonary gas exchange in patients during critical illness and surgery. Although MV is a life-saving intervention for patients in respiratory failure, an unintended side-effect of MV is the rapid development of diaphragmatic atrophy and contractile dysfunction. This MV-induced diaphragmatic weakness is labelled as 'ventilator-induced diaphragm dysfunction' (VIDD). VIDD is an important clinical problem because diaphragmatic weakness is a risk factor for the failure to wean patients from MV. Indeed, the inability to remove patients from ventilator support results in prolonged hospitalization and increased morbidity and mortality. The pathogenesis of VIDD has been extensively investigated, revealing that increased mitochondrial production of reactive oxygen species within diaphragm muscle fibres promotes a cascade of redox-regulated signalling events leading to both accelerated proteolysis and depressed protein synthesis. Together, these events promote the rapid development of diaphragmatic atrophy and contractile dysfunction. This review highlights the MV-induced changes in the structure/function of diaphragm muscle and discusses the cell-signalling mechanisms responsible for the pathogenesis of VIDD. This report concludes with a discussion of potential therapeutic opportunities to prevent VIDD and suggestions for future research in this exciting field.

13.
Free Radic Biol Med ; 224: 470-478, 2024 Aug 23.
Artigo em Inglês | MEDLINE | ID: mdl-39181477

RESUMO

Following the discovery that exercise increases the production of reactive oxygen species in contracting skeletal muscles, evidence quickly emerged that endurance exercise training increases the abundance of key antioxidant enzymes in the trained muscles. Since these early observations, knowledge about the impact that regular exercise has on skeletal muscle antioxidant capacity has increased significantly. Importantly, in recent years, our understanding of the cell signaling pathways responsible for this exercise-induced increase in antioxidant enzymes has expanded exponentially. Therefore, the goals of this review are: 1) summarize our knowledge about the influence that exercise training has on the abundance of key antioxidant enzymes in skeletal muscles; and 2) to provide a state-of-the-art review of the nuclear factor erythroid 2-related factor (Nrf2) signaling pathway that is responsible for many of the exercise-induced changes in muscle antioxidant capacity. We begin with a discussion of the sources of reactive oxygen species in contracting muscles and then examine the exercise-induced changes in the antioxidant enzymes that eliminate both superoxide radicals and hydrogen peroxide in muscle fibers. We conclude with a discussion of the advances in our understanding of the exercise-induced control of the Nrf2 signaling pathway that is responsible for the expression of numerous antioxidant proteins. In hopes of stimulating future research, we also identify gaps in our knowledge about the signaling pathways responsible for the exercise-induced increases in muscle antioxidant enzymes.

14.
Artigo em Inglês | MEDLINE | ID: mdl-39205637

RESUMO

Sickle cell disease (SCD) is characterized by central (cardiac) and peripheral vascular dysfunctions, significantly diminishing exercise capacity and quality of life. While central cardiopulmonary abnormalities in SCD are known to reduce exercise capacity and quality of life; the impact of hemolysis and subsequent cell-free hemoglobin (Hb)-mediated peripheral vascular abnormalities on those outcomes are not fully understood. Despite the recognized benefits of exercise training for cardiovascular health and clinical management in chronic diseases like heart failure, there remains substantial debate on the advisability of regular physical activity for SCD patients. This is primarily due to concerns that prolonged and/or high-intensity exercise might trigger metabolic shifts leading to vaso-occlusive crises. As a result, exercise recommendations for SCD patients are often vague or nonexistent, reflecting a gap in knowledge about the mechanisms of exercise intolerance and the impact of exercise training on SCD-related health issues. This mini-review sheds light on recent developments in understanding how SCD affects exercise tolerance, with a special focus on the roles of hemolysis and the release of cell-free hemoglobin in altering cardiovascular and skeletal muscle function. Also highlighted here is the emerging research on the therapeutic effects and safety of exercise training in SCD patients. Additionally, the review identifies future research opportunities to fill existing gaps in our understanding of exercise (in)tolerance in SCD.

15.
Subst Use Misuse ; : 1-8, 2024 Aug 20.
Artigo em Inglês | MEDLINE | ID: mdl-39164965

RESUMO

Background: Over the past decade, youth e-cigarette use has grown into a national epidemic, with Native Hawaiian and Pacific Islander (NHPI) youths' rates among some of the highest in the nation. Family factors significantly contribute to NHPI youths' decisions to engage in or resist substance use, yet few studies have specifically examined familial influences on NHPI youths' substance use decision-making and behaviors. Objective: The objective of this study is to examine adult familial influences on rural NHPI youths' decisions to engage in e-cigarette use. Method: Seventeen gender-specific focus groups with NHPI youths (N = 69) from eight public schools on Hawai'i Island were conducted. Results: Two family-related themes emerged from the data: 1) parental substance use permissiveness, and 2) family normalization of e-cigarette use. Conclusions: Examining adult familial contributors to NHPI youths' e-cigarette use needs to be part of a comprehensive effort to address NHPI health and substance use disparities. Prevention interventions should be explicit in addressing the family and relational context of NHPI youths' substance use.

16.
Am J Trop Med Hyg ; 2024 Aug 13.
Artigo em Inglês | MEDLINE | ID: mdl-39137767

RESUMO

The burden of tuberculosis (TB) is disproportionate in tropical and subtropical regions, where parasitic coinfections are common. Given the significant geographical overlap between TB and intestinal parasitic infections, it is important to consider the implications of intestinal parasitic infections for the TB pandemic. Intestinal parasitic infections have been theorized to increase vulnerability to TB by altering the inflammatory milieu, inducing undernutrition that blunts the immune response, and affecting drug pharmacokinetics. In this perspective piece, we provide a background of the epidemiological and immunological evidence that links parasitic infections to increased risk of TB progression and worse treatment outcomes. We also identify gaps in our knowledge and call for increased research on TB-parasitic coinfections to ensure action on a potentially widespread TB comorbidity.

17.
Open Forum Infect Dis ; 11(7): ofae309, 2024 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-38975247

RESUMO

Background: Fecal microbiota transplantation (FMT) is recommended for the treatment of recurrent Clostridioides difficile infection (rCDI). In the current study, we evaluated rates of rCDI and subsequent FMT in a large metropolitan area. We compared demographic and clinical differences in FMT recipients and nonrecipients and quantified differences in outcomes based on treatment modality. Methods: A retrospective community-wide cohort study was conducted using surveillance data from the Georgia Emerging Infections Program, the Georgia Discharge Data System, and locally maintained lists of FMTs completed across multiple institutions to evaluate all episodes of C. difficile infection (CDI) in this region between 2016 and 2019. Cases were limited to patients with rCDI and ≥1 documented hospitalization. A propensity-matched cohort was created to compare rates of recurrence and mortality among matched patients based on FMT receipt. Results: A total of 3038 (22%) of 13 852 patients with CDI had rCDI during this period. In a propensity-matched cohort, patients who received an FMT had lower rates of rCDI (odds ratio, 0.6 [95% confidence interval, .38-.96) and a lower mortality rate (0.26 [.08-.82]). Of patients with rCDI, only 6% had received FMT. Recipients were more likely to be young, white, and female and less likely to have renal disease, diabetes, or liver disease, though these chronic illnesses were associated with higher rates of rCDI. Conclusions: These data suggest FMT has been underused in a population-based assessment and that FMT substantially reduced risk of recurrence and death.

18.
Cancer Discov ; 2024 Jul 26.
Artigo em Inglês | MEDLINE | ID: mdl-39058094

RESUMO

The Hippo signaling pathway is commonly dysregulated in human cancer, which leads to a powerful tumor dependency on the YAP/TAZ transcriptional coactivators. Here, we used paralog co-targeting CRISPR screens to identify the kinases MARK2/3 as absolute catalytic requirements for YAP/TAZ function in diverse carcinoma and sarcoma contexts. Underlying this observation is direct MARK2/3-dependent phosphorylation of NF2 and YAP/TAZ, which effectively reverses the tumor suppressive activity of the Hippo module kinases LATS1/2. To simulate targeting of MARK2/3, we adapted the CagA protein from H. pylori as a catalytic inhibitor of MARK2/3, which we show can regress established tumors in vivo. Together, these findings reveal MARK2/3 as powerful co-dependencies of YAP/TAZ in human cancer; targets that may allow for pharmacology that restores Hippo pathway-mediated tumor suppression.

19.
Proc Biol Sci ; 291(2026): 20240804, 2024 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-38955230

RESUMO

The evolution of nuptial gifts has traditionally been considered a harmonious affair, providing benefits to both mating partners. There is growing evidence, however, that receiving a nuptial gift can be actively detrimental to the female. In decorated crickets (Gryllodes sigillatus), males produce a gelatinous spermatophylax that enhances sperm transfer but provides little nutritional benefit and hinders female post-copulatory mate choice. Here, we examine the sexually antagonistic coevolution of the spermatophylax and the female feeding response to this gift in G. sigillatus maintained in experimental populations with either a male-biased or female-biased adult sex ratio. After 25 generations, males evolving in male-biased populations produced heavier spermatophylaxes with a more manipulative combination of free amino acids than those evolving in female-biased populations. Moreover, when the spermatophylax originated from the same selection regime, females evolving in male-biased populations always had shorter feeding durations than those evolving in female-biased populations, indicating the evolution of greater resistance. Across populations, female feeding duration increased with the mass and manipulative combination of free amino acids in the spermatophylax, suggesting sexually antagonistic coevolution. Collectively, our work demonstrates a key role for interlocus sexual conflict and sexually antagonistic coevolution in the mating system of G. sigillatus.


Assuntos
Comportamento Alimentar , Gryllidae , Comportamento Sexual Animal , Animais , Gryllidae/fisiologia , Masculino , Feminino , Coevolução Biológica , Evolução Biológica , Razão de Masculinidade
20.
Ecol Evol ; 14(7): e11661, 2024 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-38994212

RESUMO

Environmental gradients have the potential to influence genetic differentiation among populations ultimately leading to allopatric speciation. However, environmental gradients can also facilitate hybridization between closely related taxa. We investigated a putative hybrid zone in western Ecuador, involving two polytypic wren species (Aves: Troglodytidae), Campylorhynchus zonatus and C. fasciatus. Our study addressed two primary questions: (1) Is there evidence of population structure and genetic admixture between these taxa in western Ecuador? and (2) What are the relative contributions of isolation by distance and isolation by the environment to the observed genetic differentiation along the environmental gradient in this region? We analyzed 4409 single-nucleotide polymorphisms (SNPs) from 112 blood samples sequenced using ddRadSeq and a de novo assembly. The optimum number of genetic clusters ranged from 2 to 4, aligning with geographic origins, known phylogenetics, and physical or ecological constraints. We observed notable transitions in admixture proportions along the environmental gradient in western Ecuador between C. z. brevirostris and the northern and southern genetic clusters of C. f. pallescens. Genetic differentiation between the two C. f. pallescens populations could be attributed to an unreported potential physical barrier in central western Ecuador, where the proximity of the Andes to the coastline restricts lowland habitats, limiting dispersal and gene flow, especially among dry-habitat specialists. The observed admixture in C. f. pallescens suggests that this subspecies may be a hybrid between C. z. brevirostris and C. fasciatus, with varying degrees of admixture in western Ecuador and northwestern Peru. We found evidence of isolation by distance, while isolation by the environment was less pronounced but still significant for annual mean precipitation and precipitation seasonality. This study enhances our understanding of avian population genomics in tropical regions.

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