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BACKGROUND AND OBJECTIVES: Patients of low individual socioeconomic status (SES) are at a greater risk of unfavorable health outcomes. However, the association between neighborhood socioeconomic deprivation and health outcomes for patients with neurologic disorders has not been studied at the population level. Our objective was to determine the association between neighborhood socioeconomic deprivation and 30-day mortality and readmission after hospitalization for various neurologic conditions. METHODS: This was a retrospective study of nationwide Medicare claims from 2017 to 2019. We included patients older than 65 years hospitalized for the following broad categories based on diagnosis-related groups (DRGs): multiple sclerosis and cerebellar ataxia (DRG 058–060); stroke (061–072); degenerative nervous system disorders (056–057); epilepsy (100–101); traumatic coma (082–087), and nontraumatic coma (080–081). The exposure of interest was neighborhood SES, measured by the area deprivation index (ADI), which uses socioeconomic indicators, such as educational attainment, unemployment, infrastructure access, and income, to estimate area-level socioeconomic deprivation at the level of census block groups. Patients were grouped into high, middle, and low neighborhood-level SES based on ADI percentiles. Adjustment covariates included age, comorbidity burden, race/ethnicity, individual SES, and sex. RESULTS: After exclusions, 905,784 patients were included in the mortality analysis and 915,993 were included in the readmission analysis. After adjustment for age, sex, race/ethnicity, comorbidity burden, and individual SES, patients from low SES neighborhoods had higher 30-day mortality rates compared with patients from high SES neighborhoods for all disease categories except for multiple sclerosis: magnitudes of the effect ranged from an adjusted odds ratio of 2.46 (95% CI 1.60–3.78) for the nontraumatic coma group to 1.23 (95% CI 1.19–1.28) for the stroke group. After adjustment, no significant differences in readmission rates were observed for any of the groups. DISCUSSION: Neighborhood SES is strongly associated with 30-day mortality for many common neurologic conditions even after accounting for baseline comorbidity burden and individual SES. Strategies to improve health equity should explicitly consider the effect of neighborhood environments on health outcomes.

Background: Carotid stenosis is thought to be the primary risk factor for central retinal artery occlusion (CRAO); however, it is not known whether atrial fibrillation (AF)—a cardiac arrhythmia that underlies over 25% of cerebral ischemic strokes—predisposes patients to CRAO. Methods: A retrospective, observational, cohort study was performed using data from the State Inpatient Databases and State Emergency Department Databases from New York (2006–2015), California (2003–2011), and Florida (2005–2015) to determine the association between AF and CRAO. The primary exposure was hospital-documented AF. The primary end point was hospital-documented CRAO, defined as having an International Classification of Diseases, Ninth Revision, Clinical Modification , code 362.31 in the primary diagnosis position. Cause-specific hazard models were used to model CRAO-free survival among patients according to hospital-documented AF status. Results: Of 39 834 885 patients included in the study, 2 723 842 (median age, 72.7 years; 48.5% women) had AF documented during the exposure window. The median follow-up duration was 6 years and 1 month. Patients with AF were older, more likely to be of non-Hispanic White race/ethnicity, and had a higher burden of cardiovascular comorbidities compared with patients without AF. The cumulative incidence of CRAO determined prospectively after exclusions was 8.69 per 100 000 at risk in those with AF and 2.39 per 100 000 at risk in those without AF over the study period. Before adjustment, AF was associated with higher risk of CRAO (hazard ratio, 2.55 [95% CI, 2.15–3.03]). However, after adjustment for demographics, state, and cardiovascular comorbidities, there was an inverse association between AF and risk of CRAO (adjusted hazard ratio, 0.72 [95% CI, 0.60–0.87]). These findings were robust in our prespecified sensitivity analyses. By contrast, positive control outcomes of embolic and ischemic stroke showed an expected strong relationship between AF and risk of stroke. Conclusions: We found an inverse association between AF and CRAO in a large, representative study of hospitalized patients; however, this cohort did not ascertain AF or CRAO occurring outside of hospital or emergency department settings.

We sought to explore the use and feasibility of an integrated hematoma evacuation/tissue preservation system coupled with immune profiling to assess human ex vivo immune cell populations from brain hematoma samples after intracerebral hemorrhage (ICH).In this nonrandomized, noncontrolled pilot/feasibility study of 7 patients with primary supratentorial ICH, a hematoma evacuation device and integrated tissue preservation system were used to obtain hematoma samples during surgical evacuation. Samples were processed, cryopreserved, and analyzed using flow cytometry to determine the relative distribution of immune cell populations compared with peripheral blood mononuclear cells from healthy control subjects.This study demonstrates proof of concept for an integrated hematoma evacuation and sample preservation system to collect human brain hematoma samples for flow cytometry analysis after acute human ICH. In our preliminary analysis, hematoma samples demonstrated a different makeup of white blood cells than peripheral blood from healthy controls.Flow cytometry analysis of hematoma samples in ICH demonstrates the potential to provide important insights into neuroinflammation associated with ICH.

Introduction: Atrial fibrillation (AF) is a major risk factor for cerebral ischemic stroke. However, it is not known whether AF predicts the development of central retinal artery occlusion (CRAO), a form of ischemic stroke affecting the retina. Methods: A retrospective cohort study was undertaken using data from the California Healthcare Cost and Utilization Project (HCUP) State Inpatient and State Emergency Department Datasets (SID/SEDDs). Patients 18 years and older discharged from non-federal hospitals between 2005 and 2011 who did not have a history of CRAO were analyzed. The exposure variable was AF and the endpoint was CRAO, each identified using validated ICD-9-CM diagnosis codes. Association between AF and CRAO was modeled using a Fine-Gray method with death as a competing risk with adjustment for age, biological sex, race, and vascular co-morbidities. Results: A total of 12,181,778 patients were included, among these 806,397 with AF and 11,375,381 without AF. In total, 309 patients had CRAO. In an unadjusted analysis, there was a higher risk of CRAO in patients with versus without AF (HR 2.24 (95% CI: 1.51 to 3.32)). After adjustment for pre-specified covariates, there appeared to be a lower hazard of CRAO in patients with AF (aHR 0.61 (95% CI: 0.45 to 0.98)). Further analyses including cerebral ischemic stroke (aHR 1.16 (95% CI: 1.14 to 1.18)) and specifically embolic stroke (aHR 4.29 (95% CI 4.10-4.48)) as positive controls argued against overadjustment bias. We present sensitivity analyses including CRAO identified in any position of the discharge ICD list, using different ascertainment windows for AF and using broader categories of retinal ischemia. Conclusion: The incidence of CRAO was higher in patients with AF than those without AF, but the hazard of CRAO was not higher for patients with AF after adjustment for measured covariates. Endpoint and exposure ascertainment may have been limited by inclusion only of inpatient and emergency department encounters.

Racial/ethnic disparities exist in many aspects of health care, but data on racial/ethnic disparities for neurodegenerative diseases (NDDs), such as dementia and Parkinson's disease (PD), are limited.We used North and South Carolina Medicare claims from 2013 to 2017 to evaluate disparities in incidence of NDDs and in health-care utilization and outcomes for patients with NDDs.Disparities in incidence of NDD between Black and White beneficiaries narrowed by 0.37 per 100 person-years from 2014 to 2017. After thorough covariate adjustment, Black beneficiaries had a 4% higher risk of all-cause hospitalization, spent 8% more days in skilled nursing facilities and 14% fewer days in hospice facilities, were 38% less likely to receive physical/occupational therapy services, were 8% less likely to receive dementia medications, and were 19% less likely to receive PD medications than White beneficiaries.Effective system-level approaches to promote health equity in NDD diagnosis, treatment, and outcomes are clearly needed.Racial disparities in neurodegenerative disease incidence narrowed between 2014 and 2017. Black patients were less likely than White patients to receive hospice services. Black patients were less likely than White patients to receive physical therapy. Black patients were less likely than White patients to receive Alzheimer's disease or Parkinson's disease medications. There is a shortage of neurologists in counties with high dementia incidence.

Limbic-predominant age-related TDP-43 encephalopathy neuropathological change (LATE-NC) is most often seen in the oldest-old (≥ 90 years of age) but can also be present in the younger-old ( 90 years of age). In this study, we compared the neuropathological associations of LATE-NC and contribution of LATE-NC to cognitive impairment between the oldest-old and younger-old. We observed significant differences in the prevalence of LATE-NC and its association with other co-pathologies in these two age groups. LATE-NC was present in 30.9% (34/110) of the oldest-old but only 9.4% (19/203) of the younger-old. Participants of the oldest-old with LATE-NC were more likely to have hippocampal sclerosis (HS) (55.9% vs. 10.5%, p 0.001) and moderate to severe arteriolosclerosis (82.4% vs. 50%, p = 0.007), but not intermediate to high Alzheimer's disease neuropathologic change (ADNC) (70.6% vs. 59.2%, p = 0.486) or Lewy body disease (LBD) (20.6% vs. 26.3%, p = 0.793). Participants of the younger-old with LATE-NC were more likely to have intermediate to high ADNC (94.7% vs. 55.4%, p 0.001) and LBD (63.2% vs. 28.8%, p = 0.013) in addition to hippocampal sclerosis (42.1% vs. 6.5%, p 0.001), and moderate to severe arteriolosclerosis (42.1% vs. 15.2%, p = 0.020). Of note, participants with LATE-NC and no to low ADNC were very rare in the younger-old ( 1%) but relatively common in the oldest-old (9.1%). Logistic regression modeling showed that in the oldest-old, both intermediate to high ADNC and LATE-NC were independently associated with higher odds of having dementia (OR: 5.09, 95% CI [1.99, 13.06], p 0.001 for ADNC; OR: 3.28, 95% CI [1.25, 8.57], p = 0.015 for LATE-NC). In the younger-old, by contrast, intermediate to high ADNC and LBD were independently associated with higher odds of having dementia (OR: 4.43, 95% CI [2.27, 8.63], p 0.001 for ADNC; OR: 2.55, 95% CI [1.21, 5.35], p 0.014 for LBD), whereas LATE-NC did not show an independent association with dementia. Overall, LATE-NC is strongly associated with arteriolosclerosis and HS in both groups; however, in the younger-old, LATE-NC is associated with other neurodegenerative pathologies, such as ADNC and LBD; whereas in the oldest-old, LATE-NC can exist independent of significant ADNC.

Introduction: Ischemic lesions seen on diffusion weighted imaging (DWI) are associated with worsened outcomes after intracerebral hemorrhage (ICH) and are thought to arise due to microvascular damage. While hyperglycemia and diabetes mellitus contribute to small vessel disease, it is not known if these factors contribute to the development of DWI lesions and associated outcomes after ICH. Hypothesis: Indicators of diabetes/hyperglycemia will be associated with the development of DWI lesions and poor outcomes after ICH Methods: 1123 patients with MRI data from the Ethnic/Racial Variations of Intracerebral Hemorrhage (ERICH) study were included. Predictors with p Results: In univariate analysis, no measure of diabetes or hyperglycemia (medical history of diabetes, insulin or non-insulin antidiabetic medication use, blood glucose obtained by emergency medical services, blood glucose on admission, fasting blood glucose, or hemoglobin A1c) was associated with the development of DWI lesions (p>0.05). Blood glucose on admission was incorporated into the initial multivariable model (p3) showed that history of diabetes (p Conclusions: While diabetes and hyperglycemia are associated with worsened outcomes after ICH, this relationship is unexpectedly not mediated by microinfarcts despite their association with cerebral small vessel disease.

To identify biomarkers with potential to indicate severity of perihematomal edema and secondary tissue injury after intracerebral hemorrhage (ICH), and which could be used as surrogate markers in future clinical trials for novel ICH therapeutics.This exploratory cohort study compared trends in neuroinflammatory biomarker levels in 18 consecutively enrolled patients with acute supratentorial ICH and 16 patients treated with the investigational neuroprotective therapy CN-105 to identify a panel of 10 biomarkers. Biomarker levels over five days post-hemorrhage were then compared with edema volumes in a larger sample of patients treated with CN-105.Mean normalized edema volumes increased over time; higher CRP levels were associated with increased edema volumes (p = 0.006, r = 0.56). Higher IL8, IL10, MCP, and MMP-9 levels were associated with decreased edema volumes (p = 0.005, r =-0.57; p = 0.02, r =-0.51; p = 0.02, r =-0.52; p = .002, r =-0.63, respectively). IL1-RA, IL1-B, IL23, vWF, and IL17 levels were not significantly associated with edema volumes (p 0.05).This exploratory study provides some of the first insights into the longitudinal associations between markers of neuroinflammation and development of perihematomal edema and secondary tissue injury in human ICH. We hypothesize that these biomarkers could be used as surrogates for treatment effect in novel therapies intended to limit neuroinflammation after ICH.

This Viewpoint discusses cost-sharing reform for chronic disease treatments as a strategy to improve patient outcomes, promote health equity, and minimize long-term health care expenditures in the US.

Proper embryonic development requires directional axes to pattern cells into embryonic structures. In Drosophila, spatially discrete expression of transcription factors determines the anterior to posterior organization of the early embryo, while the Toll and TGFβ signalling pathways determine the early dorsal to ventral pattern. Embryonic MAPK/ERK signaling contributes to both anterior to posterior patterning in the terminal regions and to dorsal to ventral patterning during oogenesis and embryonic stages. Here we describe a novel loss of function mutation in the Raf kinase gene, which leads to loss of ventral cell fates as seen through the loss of the ventral furrow, the absence of Dorsal/NFκB nuclear localization, the absence of mesoderm determinants Twist and Snail, and the expansion of TGFβ. Gene expression analysis showed cells adopting ectodermal fates much like loss of Toll signaling. Our results combine novel mutants, live imaging, optogenetics and transcriptomics to establish a novel role for Raf, that appears to be independent of the MAPK cascade, in embryonic patterning.

Background and Purpose: Many older patients presenting with acute ischemic stroke were already taking aspirin before admission. However, the management strategy for patients with aspirin treatment failure has not been fully established. Methods: We used data from the American Heart Association Get With The Guidelines Stroke Registry to describe discharge antithrombotic treatment patterns among Medicare beneficiaries with ischemic stroke who were taking aspirin before their stroke and were discharged alive from 1734 hospitals in the United States between October 2012 and December 2017. Results: Of 261 634 ischemic stroke survivors, 100 016 (38.2%) were taking aspirin monotherapy before stroke. Among them, 44.4% of patients remained on aspirin monotherapy at discharge (20.9% 81 mg, 18.2% 325 mg, 5.3% other or unknown dose). The next most common therapy choice was dual antiplatelet therapy (24.6%), followed by clopidogrel monotherapy (17.8%). The remaining 13.2% of patients were discharged on either aspirin/dipyridamole, warfarin, or nonvitamin K antagonist oral anticoagulants with or without antiplatelet, or no antithrombotic therapy at all. Conclusions: Nearly half of patients with ischemic stroke while on preventive therapy with aspirin are discharged on aspirin monotherapy without changing antithrombotic class, while the other half are discharged on clopidogrel monotherapy, dual antiplatelet therapy, or other less common agents. These findings emphasize the need for future research to identify best management strategies for this very common and complex clinical scenario.

The extent to which healthcare worker (HCWs) experiences during the COVID-19 pandemic vary by race or ethnicity after adjustment for confounding factors is not currently known.We performed an observational prospective cohort study of 24,769 healthcare workers from 50 U.S. states and the District of Columbia, enrolled between April 10, 2020 and June 30, 2021, and evaluated participant experiences during the COVID-19 pandemic, including testing, diagnosis with COVID-19, emotional experiences, burnout, and interest in vaccines and vaccine clinical trials.After adjustment for professional role, medical history, and community characteristics, Black and Asian participants were less likely to receive SARS-CoV-2 viral testing (adjusted odds ratio (aOR) 0·82 [0·70, 0·96], p=0·012 and aOR 0·77 [0·67, 0·89], p0·001 respectively) than White participants. Hispanic participants were more likely to have evidence of COVID-19 infection (aOR 1·23 (1·00, 1·50, p=0·048). Black and Asian participants were less likely to report interest in a COVID-19 vaccine (aOR 0·11 [0·05, 0·25], p0·001 and aOR 0·48 [0·27, 0·85] p=0·012). Black participants were less likely to report interest in participating in a COVID-19 vaccine trial (aOR = 0·39 [0·28, 0·54], p0·001). Black participants were also less likely to report 3 or more daily emotional impacts of COVID-19 (aOR = 0·66 [0·53, 0·82], p=0·001). Black participants were additionally less likely to report burnout (aOR = 0·66 ([0·49, 0·95], p=0·025).In a large, national study of healthcare workers, after adjustment for individual and community characteristics, race/ethnicity disparities in COVID-19 outcomes persist. Future work is urgently needed to understand precise mechanisms behind these disparities and to develop and implement targeted interventions to improve health equity for healthcare workers.This work was funded by the Patient-Centered Outcomes Research Institute (PCORI), Contract # COVID-19-2020-001.

Failure to translate promising potential therapeutics for intracerebral hemorrhage (ICH) partially results from limited understanding of cellular mechanisms underlying brain injury and repair. Understanding neural repair mechanisms after brain injury requires intricate comprehension of microglial behavior; however, studying individual microglial cell behavior is challenging. Further single cell isolation techniques may be an excellent means to expand known differences in male and female microglial cell response to ICH. In this study, 24 h after intrastriatal collagenase injection, one male and one female CX3CR1-GFP mouse underwent ex vivo microglial cell isolation via micropipette from perihematomal regions and equivalent location of contralateral striata. After cell collection, individual and grouped cell samples underwent reverse transcription and analyses for gene expression using Fluidigm RT-PCR technology. Data were analyzed by t-tests and visualized as a heatmap of the log2 Ct values. Gene expression assays were chosen for target-specific amplification, including markers of M1 pro-inflammatory microglial phenotype (i.e., Tnf, Il6, Fcgr3/CD16), M2 anti-inflammatory markers (i.e., Mrc1/CD206, Arg1, Tgfb1), and genes involved in the toll-like receptor pathway (i.e., Tlr2, Tlr4 and Myd88). Greater number of individual microglia cells expressed Mcr1, Tlr2, and Arg1 in perihematomal tissue than in contralateral hemispheres. Additionally, more male microglia expressed Myd88, Tlr2, Il6, and Arg1 than did female microglia. Single cell microglial isolation is feasible after in vivo rodent ICH. Differential gene expression can be detected between individual cells from different brain regions and experimental conditions. Cell-specific analyses will contribute to improved understanding of microglial roles in both post-ICH pathogenesis and recovery.

Proper embryonic development requires directional axes to pattern cells into embryonic structures. In Drosophila, spatially discrete expression of transcription factors determines the anterior to posterior organization of the early embryo, while the Toll and TGFβ signalling pathways determine the early dorsal to ventral pattern. Embryonic MAPK/ERK signaling contributes to both anterior to posterior patterning in the terminal regions and to dorsal to ventral patterning during oogenesis and embryonic stages. Here we describe a novel loss of function mutation in the Raf kinase gene, which leads to loss of ventral cell fates as seen through the loss of the ventral furrow, the absence of Dorsal/NFκB nuclear localization, the absence of mesoderm determinants Twist and Snail, and the expansion of TGFβ. Gene expression analysis showed cells adopting ectodermal fates much like loss of Toll signaling. Our results combine novel mutants, live imaging, optogenetics and transcriptomics to establish a novel role for Raf, that appears to be independent of the MAPK cascade, in embryonic patterning.

Primary care professionals (PCPs) have a central role in screening for diabetic retinopathy (DR), especially in settings where access to specialty eye care is limited. Data on current DR screening practice patterns in primary care are needed to inform screening strategies.To assess the practice patterns of fundoscopic examination for DR screening in a large primary care network and to evaluate the sensitivity and accuracy of PCP fundoscopy for detecting DR.A retrospective cohort study was performed using random sampling and manual review of electronic health records of PCP fundoscopic examination documentation compared with documentation of an examination performed by an eye care professional (ophthalmologist or optometrist) within 2 years before or after primary care encounters. From a single-institution primary care network of 28 clinics, 7449 adult patients with diabetes seen at least once in the primary care network in 2019 were eligible for this study. Data from 2001 encounters were abstracted from the electronic health record for a random sample of 767 patients. Data analysis was performed from January 2021 to May 2022.Fundoscopic examination by PCPs.The frequency of PCPs performing fundoscopy at least once in the calendar year for patients with diabetes. Univariate and multivariable logistic regression analyses were performed to identify patient, clinician, and clinic factors associated with PCPs performing fundoscopy at least once in the calendar year. The PCP examination results were compared with diagnoses made by eye care professionals to assess the sensitivity and accuracy of the findings from PCP examinations.Among the 767 adult patients with diabetes included in the analysis, 387 (50.5%) were female, and the median age was 64 years (IQR, 54-71 years). Primary care professionals documented a fundoscopic examination for 93 patients (12.1%); all results were documented as normal. When eye care professional examination results were used as the reference standard, the accuracy of PCP fundoscopic examination was 62.7% (95% CI, 50.0%-73.9%) and sensitivity for detecting disease was 0.0% (95% CI, 0.0%-14.9%). No patient demographic or clinical characteristics were associated with PCPs performing fundoscopy. In multivariable logistic regression, the number of PCP years in practice was associated with greater odds of patients receiving fundoscopy at least once in the year (adjusted odds ratio per 10 years in practice, 1.26; 95% CI, 1.01-1.59; P = .04); having nurse practitioner credentials was associated with lower odds of receiving fundoscopy (adjusted odds ratio, 0.23; 95% CI, 0.04-0.79; P = .049; compared with having physician credentials); after adjusting for rural clinic location, clinic location in a primary care shortage area, and documentation of an up-to-date eye care professional examination by a PCP in the study year.In this cohort study, fundoscopic examination was rarely performed and was not sensitive for detecting DR in primary care practice. Because the rate of DR screening by eye care professionals remains low, research to explore and break down barriers to the implementation of effective primary care-based DR screening strategies, such as teleretinal imaging, is needed to prevent vision loss from undiagnosed DR.

Homeostasis in adult organs involves replacement of cells from a stem cell pool maintained in specialized niches regulated by extracellular signals. This cell-to-cell communication employs signal transduction pathways allowing cells to respond with a variety of behaviors. To study these cellular behaviors, signaling must be perturbed within tissues in precise patterns, a technique recently made possible by the development of optogenetic tools. We developed tools to study signal transduction in vivo in an adult fly midgut stem cell model where signaling was regulated by the application of light. Activation was achieved by clustering of membrane receptors EGFR and Toll, while inactivation was achieved by clustering the downstream activators ERK/Rolled and NFκB/Dorsal in the cytoplasm, preventing nuclear translocation and transcriptional activation. We show that both pathways contribute to stem and transit amplifying cell numbers and affect the lifespan of adult flies. We further present new approaches to overcome overexpression phenotypes and novel methods for the integration of optogenetics into the already-established genetic toolkit of Drosophila.

The discovery of induced pluripotent stem (iPS) cells, barely more than a decade ago, dramatically transformed the study of stem cells and introduced a completely new way to approach many human health concerns. Although advances have pushed the field forward, human application remains some years away, in part due to the need for an in-depth mechanistic understanding. The role of Wnts in stem cells predates the discovery of iPS cells with Wnts established as major pluripotency promoting factors. Most work to date has been done using mouse and tissue culture models and few attempts have been made in other model organisms, but the recent combination of clustered regularly interspaced short palindromic repeats (CRISPR) gene editing with iPS cell technology provides a perfect avenue for exploring iPS cells in model organisms. Drosophila is an ideal organism for such studies, but fly iPS cells have not yet been made. In this opinion article, we draw parallels between Wnt signaling in human and Drosophila stem cell systems, propose ways to obtain Drosophila iPS cells, and suggest ways to exploit the versatility of the Drosophila system for future stem cell studies.

During animal development, complex signals determine and organize a vast number of tissues using a very small number of signal transduction pathways. These developmental signaling pathways determine cell fates through a coordinated transcriptional response that remains poorly understood. The Wnt pathway is involved in a variety of these cellular functions, and its signals are transmitted in part through a β-catenin/TCF transcriptional complex. Here we report an in vivo Drosophila assay that can be used to distinguish between activation, de-repression and repression of transcriptional responses, separating upstream and downstream pathway activation and canonical/non-canonical Wnt signals in embryos. We find specific sets of genes downstream of both β-catenin and TCF with an additional group of genes regulated by Wnt, while the non-canonical Wnt4 regulates a separate cohort of genes. We correlate transcriptional changes with phenotypic outcomes of cell differentiation and embryo size, showing our model can be used to characterize developmental signaling compartmentalization in vivo.

During animal development, complex signals determine and organize a vast number of tissues using a very small number of signal transduction pathways. These developmental signaling pathways determine cell fates through a coordinated transcriptional response that remains poorly understood. The Wnt pathway is involved in a variety of these cellular functions, and its signals are transmitted in part through a β-catenin/TCF transcriptional complex. Here we report anin vivo Drosophilaassay that can be used to distinguish between activation, de-repression and repression of transcriptional responses, separating upstream and downstream pathway activation and canonical/non-canonical Wnt signals in embryos. We find specific sets of genes downstream of both β-catenin and TCF with an additional group of genes regulated by Wnt, while the non-canonical Wnt4 regulates a separate cohort of genes. We correlate transcriptional changes with phenotypic outcomes of cell differentiation and embryo size, showing our model can be used to characterize developmental signaling compartmentalizationin vivo.

EGF signaling is a well-known oncogenic pathway in animals. It is also a key developmental pathway regulating terminal and dorsal-ventral patterning along with many other aspects of embryogenesis. In this review, we focus on the diverse roles for the EGF pathway in Drosophila embryogenesis. We review the existing body of evidence concerning EGF signaling in Drosophila embryogenesis focusing on current uncertainties in the field and areas for future study. This review provides a foundation for utilizing the Drosophila model system for research into EGF effects on cancer.