Biology subjects

Moreno, M.

Publications and source records attributed to Moreno, M..

At least 19 recordsLinked to original sources

bioRxiv2026

Spatially resolved diversity in molecular states underlies congenital melanocytic nevi and associated tumors

The congenital melanocytic nevus (CMN) is a developmental skin disorder characterized by prenatal melanocyte overgrowth, exhibiting heterogeneity in surface size, depth, and clinical behavior. Large/giant CMN carry an elevated, anticipatory melanoma risk relative to more common, small CMN. However, deeper insights into melanocytic states, genomic and epigenomic alterations, and microenvironmental cues governing disease progression are needed to predict lesions disposed to transformation. Although large/giant CMN melanocyte heterogeneity was recently established, spatial organization of these states and their niche interactions are unknown. Using advanced spatial and single-cell transcriptomics and bulk methylomics, we characterized ten CMN, seven CMN-associated proliferative nodules and three clinically diagnosed melanomas arising in CMN from children, integrating data from healthy skin references to contextualize melanocyte states in situ. CMN-specific melanocytic states, distinct in differentiation and proliferation, were spatially stratified, with immature melanocytes in deep dermis and more differentiated melanocytes approaching the epidermis. We then constructed a robust atlas of CMN cellular states by integrating single-cell transcriptomic data from five new large/giant CMN with published datasets, using it to deconvolute the spatial information. Cell-cell communication inference uncovered enhanced signaling (e.g. pleiotrophin, IGF1, periostin, semaphorin pathways) between CMN melanocytes, fibroblasts, and hair follicle-associated cells. Analysis of CMN-derived tumors, including longitudinal cases with [≥]2 samples, revealed divergent spatial melanocytic transcription distinguishing immune-enriched lesions from tumors with oncogenic/pro-invasive signatures. Collectively, these findings establish a spatially resolved framework linking melanocyte heterogeneity, signaling, and genomic instability in CMN, providing mechanistic insights to refine risk stratification and prognosis for CMN-associated tumors.

genetics↗

bioRxiv2025

Metabolic reprogramming and gut microbiota ecology drive divergent Plasmodium vivax infection outcomes in Anopheles darlingi

Anopheles darlingi is the principal malaria vector in the Amazon basin, where Plasmodium vivax accounts for the majority of cases. Despite its epidemiological importance, the molecular and microbial determinants of A. darlingi susceptibility to P. vivax remain poorly understood. Here, we investigated vector-parasite-microbiota interactions using experimental infections with field-derived P. vivax gametocytaemic blood, which produced two distinct infection phenotypes: low and high oocyst burdens. Transcriptomic profiling of mosquito midguts across key parasite developmental timepoints revealed that low-infection mosquitoes mounted an early and sustained response characterised by activation of detoxification pathways, redox regulation, aromatic amino acid catabolism, and purine depletion, likely coordinated through neurophysiological cues, which collectively create a metabolically restrictive environment for parasite development. These physiological changes were accompanied by reduced bacterial diversity and enrichment of Enterobacteriales and Pseudomonadales, taxa previously linked to anti-Plasmodium activity. Conversely, high-infection mosquitoes exhibited limited metabolic reprogramming, expansion of Flavobacteriales, and transcriptional signatures consistent with permissive physiological states, potentially associated with reproductive trade-offs. Importantly, low infection outcomes consistently arose from bloodmeals with the lowest gametocyte densities, suggesting that host- and parasite-derived components of the bloodmeal act as early conditioning factors that prime the mosquito midgut for either resistance or susceptibility. These findings reframe A. darlingi vector competence to P. vivax not as a fixed immune trait but as a dynamic outcome of early redox, metabolic, and microbial interactions. They also highlight ecological and physiological targets for transmission-blocking strategies and reinforce the importance of studying vector-parasite interactions in regionally relevant systems.

molecular biology↗

bioRxiv2025

Dorsal Striatum Parvalbumin interneurons translatome unveiled

Parvalbumin (PV) interneurons in the dorsal striatum (DS) are fast-spiking GABAergic cells critical for feedforward inhibition and synaptic integration within basal ganglia circuits. Despite their well-characterized electrophysiological roles, their molecular identity remains incompletely defined. Using the Ribotag approach in Pvalb-Cre mice, we profiled the translatome of DS PV interneurons and identified over 2,700 transcripts significantly enriched (fold-change > 1.5) in this population. Our data validate established PV markers and reveal a distinct molecular signature of DS PV neurons compared to PV interneurons from the nucleus accumbens. Gene ontology analyses highlight prominent expression of genes related to extracellular matrix components, cell adhesion molecules, synaptic organization, ion channels, and neurotransmitter receptors, particularly those mediating glutamatergic and GABAergic signaling. Notably, perineuronal net markers were robustly expressed in DS PV interneurons and confirmed by immunofluorescence. Transcriptomic analysis of DS PV neurons following repeated d-amphetamine exposure identified Gm20683 as the only differentially expressed transcript between treated groups. Furthermore, RNAseq analysis of mice subjected to an operant behavior paradigm with two types of food reward (high-palatable diet or standard chow) identified over 1,000 and 100 genes enriched in DS PV neurons from standard and high-palatable masters, respectively. These findings provide a comprehensive molecular profile of DS PV interneurons, distinguishing them from other striatal PV populations, and reveal specific gene expression changes associated with psychostimulant exposure and reward-driven behaviors. Our findings deepen insight into the molecular mechanisms of PV interneuron activity in striatal circuits and their potential roles in neuropsychiatric, motor and reward-related disorders.

neuroscience↗

bioRxiv2025

Croaking for haste: How long does it take to describe a frog species since its discovery?

Global biodiversity faces severe anthropogenic threats, with alarming extinction rates projected for the near future. Most of Earths diversity remains undescribed, meaning countless species are doomed to extinction before being documented. Since current conservation laws consider only described species, the time to achieve a representative inventory of global biodiversity is crucial for effective conservation. Amphibians, the most endangered vertebrate class, exemplify the challenge: while the number of threatened species rises, new species descriptions rapidly increase, and hundreds of candidate species are flagged annually worldwide. We analyzed all anuran species described from the year 2000 to 2023 across four biodiversity-rich tropical regions to investigate the time required to describe new frog species. We quantified the time needed to collect the type series, the number and timing of expeditions, the lag between collection and publication of the species description, and the total time. Additionally, we explored temporal trends and the effect of selected abiotic variables. On average, it takes 11.3 years to formally describe a frog species since the collection of the first specimen, with 4.5 years spent on specimen collection and 6.8 years on description and publication. These figures were consistent across three of the four regions analyzed. Alarmingly, the time required to describe new species is globally increasing, exacerbating the so-called taxonomic impediment. Only 36% of species were described within five years of collection, highlighting the importance of biological collections as reservoirs of undescribed diversity while also calling for specimen revision after expeditions. These results raise concerns about the effectiveness of current taxonomic and conservation practices in addressing the biodiversity crisis. We call for a global effort to prioritize taxonomic research and discuss innovative taxonomic and conservation approaches. Under current practices, and given the observed timelines, we will lose the race against extinction for many species.

zoology↗

bioRxiv2025

The dispersal of domestic cats from Northern Africa and their introduction to Europe over the last two millennia

The domestic cat (Felis catus) descends from the African wildcat subspecies Felis lybica lybica. Its global distribution alongside humans testifies to its successful adaptation to anthropogenic environments. Uncertainty remains regarding whether domestic cats originated in the Levant, Egypt or elsewhere in its natural range, and on the timing and circumstances of their dispersal into Europe. By analysing 87 ancient and modern cat genomes, we demonstrate that domestic cats did not spread to Europe with Neolithic farmers, as previously thought. Conversely, our results suggest that they were introduced to Europe over the last 2,000 years, most likely from North Africa. We also demonstrate that a separate earlier (1st millennium BCE) introduction of wildcats from Northwest Africa originated the present-day wild population in Sardinia.

evolutionary biology↗

bioRxiv2024

The Immunoregulatory Architecture of the Adult Oral Cavity

The immunoregulatory architecture of human oral tissues remains poorly defined despite their central role as barrier interfaces. We present the first integrated single-cell and dual-platform spatial-proteotranscriptomic atlas of oral tissues, profiling >250,000 single-cell transcriptomes and >4 million spatially-resolved cells across 13 niches. Using our AI-enabled AstroSuite (TACIT, Constellation, STARComm, hist2omics), we defined tissue cellular neighborhoods (TCNs) and multicellular interaction modules (MCIMs) in health, revealing peri-epithelial fibroblast-centered hubs enriched for effector cytokines. We harmonized eight fibroblast subtypes (universal, immune, peri-epithelial, peri-vascular, peri-neural, APC-like, stress-responsive, and myofibroblasts) with stress-responsive subtypes partitioning between mucosae (Type I) and glands (Type II). Spatial multiomics mapped receptor-ligand circuits and showed mucosal stress-responsive fibroblasts as immunoregulatory hubs. In chronic periodontitis, niche-aware integration of healthy and diseased datasets revealed rewiring of fibroblast phenotypes and ligand::receptor networks into interdigitated inflammatory and reparative niches. Disease neighborhoods exhibited fragmentation, expansion of MHC-I, MHC-II, and PD-L1 fibroblasts, and predicted spatial engagement with T cells at ectopic lymphoid structures. Drug2Cell analysis highlighted druggable stromal::immune networks. Together, this proteotranscriptomic atlas positions fibroblasts as central architects of structural immunity in human oral tissues and establishes a scalable framework for precision targeting of stromal::immune ecosystems across other barrier organs in health and chronic disease.

cell biology↗

bioRxiv2024

Multi-modal refinement of the human heart atlas during the first gestational trimester

1.Forty first-trimester human hearts were studied to lay groundwork for further studies of principles underlying congenital heart defects. We first sampled 49,227 cardiac nuclei from three fetuses at 8.6, 9.0, and 10.7 post-conceptional weeks (pcw) for single-nucleus RNA sequencing, enabling distinction of six classes comprising 21 cell types. Improved resolution led to identification of novel cardiomyocytes and minority autonomic and lymphatic endothelial transcriptomes, among others. After integration with 5-7 pcw heart single-cell RNAseq, we identified a human cardiomyofibroblast progenitor preceding diversification of cardiomyocyte and stromal lineages. Analysis of six Visium sections from two additional hearts was aided by deconvolution, and key spatial markers validated on sectioned and whole hearts in two- and three-dimensional space and over time. Altogether, anatomical-positional features including innervation, conduction and subdomains of the atrioventricular septum translate latent molecular identity into specialized cardiac functions. This atlas adds unprecedented spatial and temporal resolution to the characterization of human-specific aspects of early heart formation.

developmental biology↗

bioRxiv2024

Deconvoluted methylation profiles discriminate between closely related melanocytic nevi

Congenital melanocytic nevi (CMN) and common acquired melanocytic nevi (AMN) are melanoma-predisposing skin conditions presenting excessive numbers of melanocytes but arising at different times in life. Appropriately weighted whole-genome methylation analysis can be used as a basis for further research in dermatopathology and as applied here provides new insights into nevus biology.

cancer biology↗

bioRxiv2024

Braf-mutant Schwann cells divert to a repair phenotype to induce congenital demyelinating neuropathy

RASopathies, rare congenital syndromes affecting multiple organ systems, often include peripheral neuropathy of unknown origin. While RASopathy-associated gene variants are proto-oncogenic, the impact of timing and mosaicism on pathogenicity remains poorly understood. Here, we investigate the links between Braf, a key mitogen-activated protein kinase (MAPK) effector, and peripheral neuropathy. By targeting Braf p.V600E, an oncogenic variant found in mosaic RASopathies, to embryonic Mpz-expressing cells in mice, we induced a congenital Charcot-Marie-Tooth-like degenerative neuropathy. This phenotype was characterized by hyperplastic nerves, hindlimb weakness, and unexpectedly reduced body size. Constitutively active Braf expanded a Jun+ Schwann cell repair state, impairing myelination and nerve homeostasis. To examine relevance to RASopathies, we differentiated patient-derived stem cells bearing the cardio-facio-cutaneous syndrome-associated BRAF p.Q257R variant into Schwann cells. Compared to wild-type controls, CFC-derived cells failed to acquire mature phenotypes, instead exhibiting progenitor or repair-type transcriptional profiles. Our findings implicate somatic mosaicism in the unresolved genetic heterogeneity of neuropathies and expand the candidate gene list for peripheral nerve disorders. Moreover, they reveal a MAPK-dependent mechanism linking neural crest-derived Schwann cell dysfunction to both body growth and nerve homeostasis, providing new insights into the mechanisms in RASopathy-associated neuropathy and potential therapeutic targets.

developmental biology↗

bioRxiv2024

Odor-induced persistent neural activity in associativeencoding in humans

This study explored the impact of brief exposure to odor cues on sustained neural activity during a 6-second delay period before memory encoding of a picture image. Combining univariate and multivariate ERP analytical approaches, our results align with nonhuman data, indicating that odor cues induced sustained neural activity in humans, persisting beyond the odor exposure throughout the nearly 6-second delay period. We observed higher amplitude of sustained ERPs for unpleasant compared to pleasant odor cues. Additionally, participants exhibited more confident memory recall for pictures preceded by unpleasant rather than pleasant odor cues during encoding, underscoring the influence of brief odor cues on memory formation for temporally distant events. In conclusion, this study revealed that brief exposure to odor cues induced sustained neural activity in humans, with distinct effects on memory formation along the pleasantness dimension, emphasizing the lasting impact of olfactory stimuli on cognitive processes.

neuroscience↗

bioRxiv2024

From Nutritional Patterns to Behavior: High-Fat Diet Influences on Inhibitory Control, Brain Gene Expression and Metabolomics in Rats

BackgroundImpulsive and compulsive behaviors are associated with inhibitory control deficits. Diet plays a pivotal role in normal development, impacting both physiology and behavior. However, the specific effects of high-fat diets (HFD) on inhibitory control have not received adequate attention. ObjectivesThis study aimed to explore how exposure to an HFD from postnatal day (PND) 33 to PND77 affects impulsive and compulsive behaviors. MethodsThe experiment involved 40 Wistar rats, half of which were male and subjected to the HFD or Chow diets. Several tasks were employed to assess behavior, including the Variable Delay to Signal (VDS), the Five Choice Serial Reaction Time Task (5-CSRTT), the Delay Discounting Task (DDT), and the Rodent Gambling Task (rGT). Genetic analyses were performed on the frontal cortex, and metabolomics and fatty acid profiles were examined using stool samples collected on PND298. ResultsThe study revealed that rats exposed to the HFD exhibited heightened impulsivity in the VDS and in the 5-CSRTT, suggesting an increase in motor impulsivity. Notably, no significant effect was observed in the DDT. Surprisingly, the HFD-exposed group demonstrated reduced levels of impulsive-like behaviors, and a different decision making, in the rGT. Furthermore, abnormal gene regultation linked to brain plasticity and dopamine were identified in the frontal cortex. Metabolomics analysis of stool samples, collected in adulthood, indicated lower levels of fatty acids. DiscussionThese results suggest that HFD exposure during adolescence may create a lasting vulnerability to inhibitory control deficits, specifically in terms of motor impulsivity, and in gene expression as well as in metabolomics profile.

neuroscience↗

bioRxiv2023

What does the fox (genome) say? A chromosome-level assembly for the gray fox (Urocyon cinereoargenteus)

Reference genome assemblies have been created from multiple lineages within the Canidae family, however, despite its phylogenetic relevance as a basal genus within the clade, there is currently no reference genome for the gray fox (Urocyon cinereoargenteus). Here, we present a chromosome-level assembly for the gray fox (U. cinereoargenteus), which represents the most contiguous, non-domestic canid reference genome available to date, with 90% of the genome contained in just 34 scaffolds and a contig N50 and scaffold N50 of 59.4 and 72.9 Megabases (Mb), respectively. Repeat analyses identified an increased number of simple repeats relative to other canids. Based on mitochondrial DNA, our Vermont sample clusters with other gray fox samples from the northeastern US and contains slightly lower levels of heterozygosity than gray foxes on the west coast of California. This new assembly lays the groundwork for future studies to describe past and present population dynamics, including the delineation of evolutionarily significant units of management relevance. Importantly, the phylogenetic position of Urocyon allows us to verify the loss of PRDM9 functionality in the basal canid lineage, confirming that pseudogenization occurred at least 10 million years ago.

genomics↗

bioRxiv2023

The Genomic Legacy of Human Management and sex-biased Aurochs hybridization in Iberian Cattle

Cattle have been a valuable economic resource and cultural icon since prehistory. From the initial expansion of domestic cattle into Europe during the Neolithic period, taurine cattle (Bos taurus) and their wild ancestor, the aurochs (B. primigenius), had overlapping ranges, leading to ample opportunities for mating (whether intended by farmers or not). We performed a bioarchaeological analysis of 24 Bos remains from Iberia dating from the Mesolithic to the Roman period. The archaeogenomic dataset allows us to investigate the extent of domestic-wild hybridization over time, providing insight into the species behavior and human hunting and management practices by aligning changes with cultural and genomic transitions in the archaeological record. Our results show frequent hybridization during the Neolithic and Chalcolithic, likely reflecting a mix of hunting and herding or relatively unmanaged herds, with mostly male aurochs and female domestic cattle involved in hybridization. This is supported by isotopic evidence consistent with ecological niche sharing, with only a few domestic cattle possibly being managed. The proportion of aurochs ancestry remains relatively constant from about 4000 years ago, probably due to herd management and selection against first generation hybrids, coinciding with other cultural transitions. The constant level of wild ancestry ({bsim}20%) continues into modern western European breeds including the Spanish Lidia breed which is bred for its aggressiveness and fighting ability, but does not display elevated levels of aurochs ancestry. This study takes a genomic glance at the impact of human actions and wild introgression in the establishment of cattle as one of the most important domestic species today.

genomics↗

bioRxiv2023

Functional diversity reduces the risk of hydraulic failure in tree mixtures through hydraulic disconnection

Forest ecosystems are increasingly threatened by anthropogenic pressures, especially by the increase in drought frequency and intensity. Tree species mixtures could improve resilience to diverse global anthropogenic pressures. However, there is still little consensus on how tree diversity affects water stress. Although some studies suggest that mixing species with different drought response strategies could be beneficial, the underlying mechanisms have seldom been identified. By combining a greenhouse experiment and a soil-plant-atmosphere hydraulic model, we explored whether mixing a drought avoidant (Pinus halepensis) and a drought tolerant (Quercus ilex) tree species could reduce plant water stress (defined as the risk of hydraulic failure) during extreme drought, compared to their respective monocultures. Our experiment showed that mixing species with divergent drought response strategies had a neutral effect on the drought-avoidant species and a positive effect on the drought-tolerant species. The model simulations further suggested that the beneficial effect of mixture on plant water stress during extreme drought was related to changes in the hydraulic connection of the plant from both the soil and the atmosphere. The ability of the drought-avoidant species to disconnect from the soil and the atmosphere limits its exposure to water stress, whereas the ability of the drought-tolerant species to increase its hydraulic connection to the soil lowers its hydraulic risk. This study brings a new insight on the mechanisms and traits combinations improving drought resistance in diversified forests and plantations, with important implications for forest management under climate change.

ecology↗

bioRxiv2023

Distinct excitability of thalamocortical neurons correlates with the presence of cerebellar afferents

Thalamocortical (TC) neurons within the ventrolateral thalamus (VL) receive projections from the cerebellum and the basal ganglia (BG) to facilitate motor and non-motor functions. Tonic and rebound firing patterns in response to excitatory cerebellar and inhibitory BG inputs, respectively, are a canonical feature of TC neurons and plays a key role in signal processing. The intrinsic excitability of TC neurons has a strong influence on how they respond to synaptic inputs, however, it is unknown whether their afferents influence their firing properties. Understanding the input-specific firing patterns could shed light into movement disorders with cerebellar or BG involvement. Here, we used whole-cell electrophysiology in brain slices from C57BL/6 mice to investigate the firing of TC neurons with optogenetic confirmation of cerebellar or BG afferents. TC neurons with cerebellar afferents exhibited higher tonic and rebound firing rates than those with BG afferents. This increased firing was associated with faster action potential depolarization kinetics and a smaller afterhyperpolarization potential. We also found differences in the passive membrane properties and sag currents during hyperpolarization. Despite higher rebound firing in TC neurons with cerebellar afferents, there were no differences in T-type calcium channel function compared to those with BG inputs. These data suggest input-specific differences in sodium and SK, but not T-type calcium channels, impact firing properties in TC populations. Altogether, we showed that the pronounced divergence observed in TC neuron firing properties correlate with its heterogeneous anatomical connectivity, which could signify a distinct signal integration and processing by these neurons.

neuroscience↗

bioRxiv2022

The HDAC inhibitor trichostatin A impairs pancreatic β-cell function through an epigenome-wide reprogramming

ObjectiveThe pancreatic islets of Langerhans contain distinct cell subtypes including insulin-producing {beta} cells. Although their cell-specific gene expression pattern defines their identity, the underlying molecular network driving this transcriptional specificity is not fully understood. Among the numerous transcriptional regulators, histone deacetylases (HDAC) enzymes are potent chromatin modifiers which directly regulate gene expression through deacetylation of lysine residues within specific histone proteins. The precise molecular mechanisms underlying HDAC effects on cellular plasticity and {beta}-cell identity are currently unknown. MethodsThe pharmacological inhibition of HDAC activity by trichostatin A (TSA) was studied in the mouse Min6 and human EndocBH1 cell lines, as well as primary mouse sorted {beta} cells and human pancreatic islets. The molecular and functional effects of treating these complementary {beta}-cell models with TSA was explored at the epigenomic and transcriptomic level through next-generation sequencing of chromatin immunoprecipitation (ChIP) assays (ChIP-seq) and RNA sequencing (RNA-seq) experiments, respectively. ResultsWe showed that TSA alters insulin secretion associated with {beta}-cell specific transcriptome programming in both mouse and human {beta}-cell lines, as well as on human pancreatic islets. We also demonstrated that this alternative {beta}-cell transcriptional program in response to HDAC inhibition is related to an epigenome-wide remodeling at both promoters and enhancers. ConclusionsTaken together, our data indicate that full HDAC activity is required to safeguard the epigenome, to protect against loss of {beta}-cell identity with unsuitable expression of genes associated with alternative cell fates.

genomics↗

bioRxiv2022

Diel activity patterns of vector mosquito species in the urban environment: Implications for vector control strategies

Florida and Texas continue to be afflicted by mosquito-borne disease outbreaks such as dengue and West Nile virus disease and were the most affected states by the Zika outbreak of 2016-2017. Mathematical models have been widely used to study the population dynamics of mosquitoes as well as to test and validate the effectiveness of arbovirus outbreak responses and mosquito control strategies. The objective of this study is to assess the diel activity of mosquitoes in Miami-Dade, Florida and Brownsville, Texas, and to evaluate the effectiveness of simulated adulticide treatments on local mosquito populations. To assess variations in the diel activity patterns, mosquitoes were collected hourly for 96 hours once a month from May through November 2019 in Miami-Dade and Brownsville, Texas. We then performed a PERMANOVA followed by the SIMPER method to assess which species contributed the most to the observed differences. Finally, we used a mathematical model to simulate the population dynamics of 5 mosquito vector species to evaluate the effectiveness of the simulated adulticide applications. A total of 14,502 mosquitoes comprising 17 species were collected in Brownsville and 10,948 mosquitoes comprising 19 species were collected in Miami-Dade. Aedes aegypti was the most common mosquito species collected every hour in both cities and peaking in abundance in the morning and the evening. Our modeling results indicate that the effectiveness of adulticide applications varied greatly depending on the hour of the treatment. Overall, 9 PM was the best time for adulticide applications targeting all mosquito vector species in Miami-Dade and Brownsville. Our results indicate that the timing of adulticide spraying interventions should be carefully considered by local authorities based on the ecology of mosquito species in the focus area.

ecology↗

bioRxiv2022

Multiple congenital malformations arise from somatic mosaicism for constitutively active Pik3ca signalling

Recurrent missense mutations of the PIK3CA oncogene are among the most frequent drivers of human cancers. These often lead to constitutive activation of its product p110, a phosphatidylinositol 3-kinase (PI3K) catalytic subunit. In addition to causing a broad range of cancers, the H1047R mutation is also found in affected tissues of a distinct set of congenital tumors and malformations. Collectively termed PIK3CA-related disorders (PRDs), these lead to overgrowth of brain, adipose, connective and musculoskeletal tissues and/or blood and lymphatic vessel components. Vascular malformations are frequently observed in PRD, due to cell-autonomous activation of PI3K signaling within endothelial cells. These, like most muscle, connective tissue and bone, are derived from the embryonic mesoderm. However, important organ systems affected in PRDs are neuroectodermal derivatives. To further examine their development, we drove the most common post-zygotic activating mutation of Pik3ca in neural crest and related embryonic lineages. Outcomes included macrocephaly, cleft secondary palate and more subtle skull anomalies. Surprisingly, Pik3ca-mutant subpopulations of neural crest origin were also associated with widespread cephalic vascular anomalies. Mesectodermal neural crest is a major source of non-endothelial connective tissue in the head, but not the body. To examine the response of vascular connective tissues of the body to constitutive Pik3ca activity during development, we expressed the mutation by way of an Egr2 (Krox20) Cre driver. Lineage tracing led us to observe new lineages that had normally once expressed Krox20 and that may be co-opted in pathogenesis, including vascular pericytes and perimysial fibroblasts. Finally, Schwann cell precursors having transcribed either Krox20 or Sox10 and induced to express constitutively active PI3K were associated with vascular and other tumors. These murine phenotypes may aid discovery of new candidate human PRDs affecting craniofacial and vascular smooth muscle development as well as the reciprocal paracrine signaling mechanisms leading to tissue overgrowth.

developmental biology↗