Biology subjects

Sanchez, A. M.

Publications and source records attributed to Sanchez, A. M..

6 recordsLinked to original sources

bioRxiv2026

Genetic and Epigenetic Landscape of Self-Identified Hispanics/Latino in All Of Us

Human genetic studies still underrepresent many populations, limiting discovery and interpretation of medically relevant variation. Extensive admixture in self-identified Hispanic/Latino populations increases the need for representative reference data and ancestry-aware interpretation of medically relevant variation. We used long-read sequencing to analyze genetic variation, ancestry, and DNA methylation in 1,490 self-identified Hispanic/Latino participants from the All of Us Research Program. We identified 10 million novel variants and more than 100 candidate phenotype associations, with fine-mapping prioritizing structural variants over nearby single-nucleotide variants in more than half. We linked 3,329 tandem repeats to DNA methylation, resolved widespread allele-specific methylation, and identified ancestry-linked regulation across paralogous genes. These results reveal previously inaccessible genetic and regulatory variation and show the value of long-read sequencing for diverse populations.

genetics↗

bioRxiv2026

Functional Reorganization of Motor Subcircuits in Parkinson's disease

Parkinsons disease disrupts motor control across multiple body parts, yet the neural mechanisms underlying these impairments remain incompletely defined. We compared resting-state functional connectivity in people with mild-to-moderate Parkinsons disease (n = 58) and neurotypical older adults (n = 24), focusing on regions implicated in internally generated (IG) and externally generated (EG) movement pathways. For our analysis, we leveraged the reproducible NeuroMark independent component template and motor effector-specific mapping of primary motor cortex (M1). Our results reveal both increased and decreased connectivity patterns in Parkinsons disease: M1 subregions associated with control of the leg, hand, and larynx showed robust increases in connectivity exclusively with cerebellar territories, particularly Crus II and Lobules VIIIa/VIIIb. The postcentral gyrus (primary somatosensory cortex) showed primarily increased connectivity with cerebellar regions and the insula. In contrast, the caudate nucleus displayed a mixed profile, with increased connectivity to the superior temporal gyrus and decreased connectivity to the superior medial frontal gyrus and cerebellar Crus II. Our motor effector-specific analysis of disease severity scores (MDS-UPDRS) in people with Parkinsons disease revealed mild impairments across all categories (leg, hand, larynx) but disproportionately greater hand-related deficits, suggesting that some of the observed M1 connectivity differences may be influenced by these behavioral asymmetries. These anatomically precise, effector-specific alterations suggest compensatory recruitment of cerebellar circuits in Parkinsons disease and provide a framework for targeting motor subcircuits in rehabilitation, including dance-based interventions.

neuroscience↗

bioRxiv2026

Which, when and where traits matter: functional trait-mediated species associations shift with microenvironmental and climatic variation

O_LIPredicting coexistence in species-rich plant communities requires understanding the role of functional traits in species interactions and their resilience to environmental variation. C_LIO_LIIn a manipulative factorial field experiment in an annual community (>45,000 individuals and 45 species), we followed plant associations from seedling to adult on both preserved and altered biological soil crust over two years with contrasting weather conditions. Neighborhood models quantified how among-species differences in key functional traits affected coexistence and how these effects varied in response to ontogenetic stage, environmental variation and spatial scale. C_LIO_LITrait-based models revealed a prevalent negative relationship between functional differences and species associations, but these relationships varied predictively with stage, environment and spatial scale. Functional dissimilarity in traits such as specific leaf area, seed mass, and reproductive-to-vegetative biomass ratio consistently mediated species segregation, especially during wet years and among seedlings, while biological soil crust disturbance altered trait-mediated associations differently at fine and coarse spatial scales. C_LIO_LITrait-mediated species associations shift predictably with environmental variation, suggesting that coexistence reflects a dynamic balance between environmental filtering and competitive interactions. This work provides novel experimental evidence of when, where, and which traits predict community assembly, which has implications for forecasting biodiversity responses to global environmental change. C_LI

ecology↗

bioRxiv2023

Mobile brain imaging in butoh dancers: from rehearsals to public performance

Dissecting the neurobiology of dance would shed light on a complex, yet ubiquitous, form of human communication. In this experiment, we sought to study, via mobile electroencephalography (EEG), the brain activity of five experienced dancers while dancing butoh, a postmodern dance that originated in Japan. We report the experimental design, methods, and practical execution of a highly interdisciplinary project that required the collaboration of dancers, engineers, neuroscientists, musicians, and multimedia artists, among others. We explain in detail how we technically validated all our EEG procedures (e.g., via impedance value monitoring) and how we minimized potential artifacts in our recordings (e.g., via electrooculography and inertial measurement units). We also describe the engineering details and hardware that enabled us to achieve synchronization between signals recorded in different sampling frequencies, and a signal preprocessing and denoising pipeline that we have used to re-sample our data and remove power line noise. As our experiment culminated in a live performance, where we generated a real-time visualization of the dancers interbrain synchrony on a screen via an artistic brain-computer interface, we outline all the methodology (e.g., filtering, time-windows, equation) we used for online bispectrum estimations. We also share all the raw EEG data and codes we used in our recordings. We, lastly, describe how we envision that the data could be used to address several hypotheses, such as that of interbrain synchrony or the motor theory of vocal learning. Being, to our knowledge, the first study to report synchronous and simultaneous recording from five dancers, we expect that our findings will inform future art-science collaborations, as well as dance-movement therapies.

neuroscience↗

bioRxiv2022

Inorganic polyphosphate abets silencing of a sub-telomeric gene cluster in fission yeast

Inorganic polyphosphate (PolyP) is a ubiquitous polymer that plays sundry roles in cell and organismal physiology. Whereas there is evidence for polyphosphate in the cell nucleus, it is unclear whether and how physiological levels of PolyP impact transcriptional regulation in eukarya. To address this issue, we performed transcriptional profiling of fission yeast vtc4{Delta} cells, which lack the catalytic subunit of the Vtc4/Vtc2 polyphosphate polymerase complex and thus have no detectable intracellular PolyP. Deleting Vtc4 elicited the de-repression of four protein-coding genes - SPAC186.04c, gdt1/SPAC186.05, SPAC186.06, and SPAC750.01 - located within a sub-telomeric region of the right arm of chromosome I that is known to be transcriptionally silenced by the TORC2 complex. These sub-telomeric genes were equally de-repressed in vtc2{Delta} cells and in cells expressing polymerase-dead Vtc4, signifying that PolyP synthesis is necessary to abet TORC2-dependent locus-specific gene silencing.

genetics↗

bioRxiv2019

Inositol pyrophosphates impact phosphate homeostasis via modulation of RNA 3’ processing and transcription termination

Fission yeast phosphate acquisition genes pho1, pho84, and tgp1 are repressed in phosphate-rich medium by transcription of upstream lncRNAs. Here we show that phosphate homeostasis is subject to metabolite control by inositol pyrophosphates (IPPs), exerted through the 3-processing/termination machinery and the Pol2 CTD code. Increasing IP8 (via Asp1 IPP pyrophosphatase mutation) de-represses the PHO regulon and leads to precocious termination of prt lncRNA synthesis. pho1 de-repression by IP8 depends on cleavage-polyadenylation factor (CPF) subunits, termination factor Rhn1, and the Thr4 letter of the CTD code. pho1 de-repression by mutation of the Ser7 CTD letter depends on IP8. Simultaneous inactivation of the Asp1 and Aps1 IPP pyrophosphatases is lethal, but this lethality is suppressed by mutations of CPF subunits Ppn1, Swd22, Ssu72, and Ctf1 and CTD mutation T4A. Failure to synthesize IP8 (via Asp1 IPP kinase mutation) results in pho1 hyper-repression. Synthetic lethality of asp1{Delta} with Ppn1, Swd22, and Ssu72 mutations argues that IP8 plays an important role in essential 3-processing/termination events, albeit in a manner genetically redundant to CPF. Transcriptional profiling delineates an IPP-responsive regulon composed of genes overexpressed when IP8 levels are increased. Our results establish a novel role for IPPs in cell physiology.

genetics↗