Search bioRxiv⌕ Search

Biology subjects

ONeill, K.

Publications and source records attributed to ONeill, K..

4 recordsLinked to original sources

Bridging Biomedical Atlas Ecosystem: Cross-Atlas Alignment And Scalable Tissue Specimen Registration

Over the last five years, over 13,000 tissue datasets with 200+ million cells from 20 consortia have been spatially registered into the Human Reference Atlas (HRA) common coordinate framework (CCF). The shared 3D spatial and semantic reference system enables exploration of datasets in the context of all other data across organs, assay types, and spatial scales. However, manual registration of individual samples remains resource intensive, posing feasibility challenges exacerbated by the proliferation of samples, assays, and atlasing efforts. This paper presents two approaches to scale up HRA construction: (1) projecting data across biomedical reference atlas systems and (2) using millitomes to bulk register tissue blocks into a reference organ. Both methods use the AutoMated Alignment and Projection (AMAP) pipeline to align 3D mesh models using point cloud registration. We demonstrate the evolving HRA-aligned atlas ecosystem for 6 models from the SPARC Program (heart), Gut Cell Atlas (large intestine), 500-subject consensus kidneys, and the Julich Brain Atlas. Additionally, we used AMAP to project 7 millitome models across 5 organs onto the HRA ecosystem, integrating 300+ tissue extraction sites. AMAP enables scalable tissue registration of data across atlas ecosystems enabling the construction of detailed reference maps of the human body.

bioinformatics↗

ALS molecular subtypes are a combination of cellular, genetic, and pathological features learned by deep multiomics classifiers

Amyotrophic Lateral Sclerosis (ALS) is a complex syndrome with multiple genetic causes and wide variation in disease presentation. Despite this general heterogeneity, several common factors have been identified. For example, nearly all patients show pathological accumulations of phosphorylated TDP-43 protein in affected regions of the motor cortex and spinal cord. Moreover, large patient cohort studies have revealed that most patient samples can be grouped into a small number of ALS subtypes, as defined by their transcriptomic profiles. These ALS molecular subtypes can be grouped by whether postmortem motor cortex samples display signatures of: mitochondrial dysfunction and oxidative stress (ALS-Ox), microglial activation and neuroinflammation (ALS-Glia), or dense TDP-43 pathology and associated transposable element de-silencing (ALS-TE). In this study, we have built a deep layer ALS neural network classifier (DANcer) that has learned to accurately assign patient samples to these ALS subtypes, and which can be run on either bulk or single-cell datasets. Upon applying this classifier to an expanded ALS patient cohort from the NYGC ALS Consortium, we show that ALS Molecular Subtypes are robust across clinical centers, with no new subtypes appearing in a cohort that has quadrupled in size. Signatures from two of these molecular subtypes strongly correlate with disease duration: ALS-TE signatures in cortex and ALS-Glia signatures in spinal cord, revealing molecular correlates of clinical features. Finally, we use single nucleus RNA sequencing to reveal the cell type-specific contributions to ALS subtype, as determined by our single-cell classifier (scDANCer). Single-cell transcriptomes reveal that ALS molecular subtypes are recapitulated in neurons and glia, with both ALS-wide shared alterations in each cell type as well as ALS subtype-specific alterations. In summary, ALS molecular subtypes: (1) are robust across large cohorts of sporadic and familial ALS patient samples, (2) represent a combination of cellular, genetic, and pathological features, and (3) correlate with clinical features of ALS. O_FIG O_LINKSMALLFIG WIDTH=200 HEIGHT=148 SRC="FIGDIR/small/603731v1_ufig1.gif" ALT="Figure 1"> View larger version (42K): org.highwire.dtl.DTLVardef@df6e03org.highwire.dtl.DTLVardef@af9beborg.highwire.dtl.DTLVardef@12594f1org.highwire.dtl.DTLVardef@557dae_HPS_FORMAT_FIGEXP M_FIG O_FLOATNOFigure 0:C_FLOATNO Graphical Abstract - ALS molecular subtypes are a combination of cellular, genetic, and pathological features learned by deep multiomics classifiers. C_FIG

genomics↗

An epigenetic clock to estimate the age of living beluga whales

IntroductionDNA methylation data facilitate the development of accurate molecular estimators of chronological age, or epigenetic clocks. We present a robust epigenetic clock for the beluga whale, Delphinapterus leucas, developed for an endangered population in Cook Inlet, Alaska, USA. Methods and ResultsWe used a custom methylation array to measure methylation levels at 37,491 cytosine-guanine sites (CpGs) from skin samples of dead whales (n = 67) whose chronological ages were estimated based on tooth growth layer groups. Using these calibration data, a penalized regression model selected 23 CpGs, providing an R2 = 0.92 for the training data; and an R2 = 0.74 and median absolute age error = 2.9 years for the leave one out cross-validation. We applied the epigenetic clock to an independent data set of 38 skin samples collected with a biopsy dart from living whales between 2016 and 2018. Age estimates ranged from 11 to 27 years. We also report sex correlations in CpG data and describe an approach of identifying the sex of an animal using DNA methylation. DiscussionThe epigenetic estimators of age and sex presented here have broad applications for conservation and management of Cook Inlet beluga whales and potentially other cetaceans.

developmental biology↗

SUCCESSFUL DEMONSTRATION OF ASSISTED GENE FLOW IN THE THREATENED CORAL ACROPORA PALMATA ACROSS GENETICALLY-ISOLATED CARIBBEAN POPULATIONS USING CRYOPRESERVED SPERM

Global change will compromise the population sizes, species ranges, and survival of economically-important plants and animals, including crops, aquaculture species, and foundational ecosystem builders. Scleractinian reef-building corals are a particular concern because they are slow-growing, long-lived, environmentally-sensitive, and concentrated in the warmest regions of the ocean. Assisted Gene Flow (AGF) is considered a viable tool to help natural plant and animal populations, including corals, adapt to changing environments. Our goal was to test for the first time whether cryopreserved coral sperm could be used to facilitate assisted gene flow between genetically-isolated populations of a Caribbean coral. We collected, pooled, and cryopreserved coral sperm from the threatened Caribbean coral Acropora palmata in the western Caribbean (Key Largo, FL), central Caribbean (Rincon, Puerto Rico), and eastern Caribbean (Curacao). Alongside freshly-collected sperm from Curacao, the cryopreserved sperm from each of these populations was used for in vitro fertilization experiments with freshly-collected eggs from Curacao. Across five egg donors, average fertilization success was 91 to 99% for CUR x CUR (fresh sperm) crosses, 37 to 82% for CUR x CUR (frozen sperm) crosses, 3 to 19% for CUR x FL (frozen sperm) crosses and 0 to 24% for CUR x PR (frozen sperm) crosses. Notably, fertilization was achieved in all four categories of crosses, showing for the first time through direct evidence that populations of A. palmata are reproductively compatible, and that genetic diversity can be transferred from one population to another for the purposes of assisted gene flow. The resulting larvae were reared in Curacao for up to 7 days, then the swimming larvae were transported to Florida for settlement and grow-out at two separate facilities, which achieved larval settlement rates of 37 to 60% across all cohorts. Larvae were reared and settled in Florida to acclimate them to the ambient water quality, microbial environment, and temperature regimes of the western genetic A. palmata population as early in their life cycle as possible. At one month, over 54% all settlers had survived, including over 3500 settlers from CUR x CUR (frozen sperm), 1200 settlers from CUR x FL (frozen sperm), and 230 settlers from CUR x PR (frozen sperm). These experiments represent the first-ever pan-Caribbean coral crosses produced in captivity and the first direct evidence that geographically-separated and genetically-isolated populations of any Caribbean coral are reproductively compatible. Moreover, with over 4700 A. palmata settlers produced using cryopreserved sperm, this represents the largest living wildlife population ever created from cryopreserved material. Together, these findings demonstrate that cryopreservation of coral sperm can enable efficient, large-scale assisted gene flow in corals. This form of assisted migration can not only help to preserve the population-level genetic diversity of extant coral populations but also help to increase population resilience to global change.

zoology↗