Year: 2021
Type: preprint
Abstract: Telomeres are regions of repetitive nucleotide sequences capping the ends of eukaryotic chromosomes that protect against deterioration, and whose lengths can be correlated with age and adverse health risk factors. Yet, given their length and repetitive nature, telomeric regions are not easily reconstructed from short-read sequencing, thus making telomere sequencing, mapping, and variant resolution challenging problems. Recently, long-read sequencing, with read lengths measuring in hundreds of kilobase pairs, has made it possible to routinely read into telomeric regions and inspect their sequence structure. Here, we describe a framework for extracting telomeric reads from whole-genome single-molecule sequencing experiments, including de novo identification of telomere repeat motifs and repeat types, and also describe their sequence variation. We find that long, complex telomeric stretches and repeats can be accurately captured with long-read sequencing, observe extensive sequence heterogeneity of human telomeres, discover and localize noncanonical telomere sequence motifs (both previously reported, as well as novel), and validate them in short-read sequence data. These data reveal extensive intra- and inter-population diversity of repeats in telomeric haplotypes, reveal higher paternal inheritance of telomeric variants, and represent the first motif composition maps of multi-kilobase-pair human telomeric haplotypes across three distinct ancestries (Ashkenazi, Chinese, and Utah), which can aid in future studies of genetic variation, aging, and genome biology.
Source: Genome Research
Language: English
Subfield: Physiology
Field: Medicine
Domain: Health Sciences
Open Access status: bronze
Funders: National Science Foundation, National Aeronautics and Space Administration, Leukemia and Lymphoma Society, Vallee Foundation, Pershing Square Sohn Cancer Research Alliance, WorldQuant Foundation, National Institutes of Health, Weill Cornell Medical College, National Science Foundation of Sri Lanka, National Institute of Mental Health, National Cancer Institute, National Institute of Allergy and Infectious Diseases, National Institute of Neurological Disorders and Stroke, Eunice Kennedy Shriver National Institute of Child Health and Human Development
Awards: G1118278778, G1247982728, G1505327534, (1) SUMMARYMASSIVELY PARALLEL DNA SEQUENCING CONTINUES TO PROVIDE ASTONISHING INSIGHTS INTO THE REGULATORY COMPLEXITY OF THE MAMMALIAN GENOME REVEALING HERITABLE AND DE NOVO OCCURRING RISK FACTORS PREDISPOSING HUMANS TO A WIDE VARIETY OF DISEASES AND DISORDERS. NOTABLY MEMBERS OF THE ENCYCLOPEDIA OF DNA ELEMENTS (ENCODE) CONSORTIUM INCLUDING CO-INVESTIGATORS DRS. MASON AND SNYDER HAVE RECENTLY MAPPED THOUSANDS OF NON-CODING REGULATORY ELEMENTS IN THE HUMAN GENOME THAT SPECIFY RISK AND PROTECTIVE SITES FOR MANY DISEASE. THESE NONCODING GENETIC VARIATIONS ALSO SHOW DIFFERENTIAL IMPACT DEPENDING ON THE EPIGENETIC CHANGES OF THE GENOME INCLUDING METHYLATION OF DNA AND CHROMATIN STATES INSIDE CELLS. YET THESE QUESTIONS HAVE NOT BEEN COMPREHENSIVELY EXAMINED IN HUMAN ASTRONAUTS DUE TO THE FACT THAT THE VERY FIRST DATA SETS THAT CAN DELINEATE THE PUTATIVE IMPACT OF GENOME-WIDE NONCODING VARIATION AND EPIGENETIC CHANGES FROM SPACE TRAVEL ARE ONLY NOW BEING GENERATED IN THE NASA TWINS STUDY.HOWEVER WITH THIS DATA FROM NASA TWINS STUDY THERE IS A UNIQUE OPPORTUNITY TO BOTH GENERATE NEW COMPUTATIONAL TOOLS FOR THE INTEGRATION OF THE DATA FROM THESE SAMPLES AND ALSO TO UTILIZE NOVEL SINGLE-CELL APPROACHES FOR EPIGENETIC STATES IN THE HUMAN CELLS TAKEN FROM SPACE. WE PROPOSE TO EXPAND AND FURTHER INTEGRATE OUR TOOLS FOR EXAMINING THE REGULATORY CHANGES TO DNA AND RNA TOGETHER CALLED "EPISUITE " WHICH WILL PROVIDE LONG-SOUGHT SOLUTIONS TO PROBLEMS IN INTEGRATIVE GENOMICS AND ESTABLISH A MORE SYSTEMS-LEVEL VIEW OF HUMAN PHYSIOLOGY DURING SPACE TRAVEL. SPECIFICALLY WE WILL OPTIMIZE AND INTEGRATE OPEN-SOURCE AND PUBLISHED BIOINFORMATICS TOOLS BETWEEN BOTH LABORATORIES (HUGE-SEQ METHYLKIT EDMR R-MAKE) EXPAND OUR CODE BASE WITH TWO NEW TOOLS (METHCLONE AND CEMBASE) AND THEN CREATE A WEB-INTERFACE FOR USERS TO UPLOAD ORGANIZE AND ANALYZE THESE DATA RELATIVE TO ENCODE PUBLIC DATA. THEN WE WILL USE NOVEL SINGLE-CELL EXPERIMENTAL METHODS (SCATAC-SEQ) TO CONFIRM AND CHARACTERIZE THE IMPACT AND SCOPE OF SUCH NONCODING AND EPIGENETIC CHANGES. TOGETHER THE DATA AND TOOLS IN EPISUITE CONCOMITANT WITH THE NEW SINGLE-CELL CHROMATIN DATA WILL ENABLE DISCOVERY AND VALIDATION OF SPECIFIC LOCI THAT REPRESENT THE GENETIC AND EPIGENETIC RISKS FACED BY ASTRONAUTS AND ALSO AN IMPROVED UNDERSTANDING OF THE REGULATORY AND GENETIC IMPACT (BMED5) OF THESE MOLECULAR CHANGES.(2) HYPOTHESISWE HYPOTHESIZE THAT SPECIFIC AREAS OF THE GENOME ARE EPIGENETICALLY DYSREGULATED AS A RESULT OF SPACE TRAVEL AND THAT SOME OF THESE AREAS DIFFER BETWEEN ASTRONAUTS. MOREOVER WE HYPOTHESIZE THAT THE ENRICHMENT OF NON-CODING VARIANTS IN DISTINCT BIOLOGICAL PATHWAYS WILL ALSO DIFFER BETWEEN ASTRONAUTS AND ANALYSIS AND INTEGRATION OF THESE DATA WILL REVEAL THE FIRST REGIONS OF "EPIGENETIC SPACE RISK" FOR THE ASTRONAUTS DELINEATED IN BMED5. TO VALIDATE THESE PREDICTIONS WE WILL PERFORM SINGLE-CELL ATAC-SEQ (ASSAY FOR TRANSPOSASE ACCESSIBLE CHROMATIN) ON CELL FRACTIONS FROM EARTH-BASED CONTROL SAMPLES AND THOSE TAKEN FROM SPACE.(3) SPECIFIC AIMSAIM 1. CREATE A WEB-BASED FRAMEWORK FOR INTEGRATING NON-CODING GENOMIC VARIATION AND DIFFERENTIAL EPIGENETIC STATES. THIS EPISUITE INTERFACE AND SET OF MACHINE-LEARNING ALGORITHMS WILL HELP ONGOING WORK WITH THE NASA TWINS STUDY AND AID FUTURE INVESTIGATIONS THAT LEVERAGE MULTI-OMICS DATA SETS FROM ASTRONAUTS. THESE DATA WILL ALSO BE LINKED TO GENE EXPRESSION DATA TO GAUGE THE IMPACT OF GENETIC AND EPIGENETIC CHANGES ON SPECIFIC BIOLOGICAL NETWORKS.AIM 2. VALIDATE THE ALTERED CHROMATIN STATES IN CELLS FROM SPACE TRAVEL AND MEASURE THE PROPORTION OF CELLS CHANGED WITH SINGLE-CELL ATAC-SEQ. WE WILL USE AN ASSAY CALLED SINGLE CELL (SCATAC-SEQ) WHICH CAN MEASURE THE SITES OF OPEN AND CLOSED CHROMATIN ON A CELL-BY-CELL BASIS. THIS WILL VALIDATE THE SITES WHERE WE OBSERVE EPIGENETIC CHANGES AND ALSO PROVIDE THE FIRST ESTIMATE OF THE PROPORTION OF CELLS EPIGENETICALLY IMPACTED BY SPACE TRAVEL., G1777513698, THE ENDS OF HUMAN CHROMOSOMES ARE CAPPED BY TELOMERES, TANDEM ARRAYS OF REPETITIVE DNA SEQUENCE AND ASSOCIATED PROTEINS, WHICH SERVE TO PROTECT CHROM, G2637629997, THIS PROPOSAL FOR A TRANSLATIONAL RESEARCH INSTITUTE IS SUBMITTED ON BEHALF OF A CONSORTIUM OF NON-PROFIT ACADEMIC INSTITUTIONS IN RESPONSE TO NASA C, The Spatiotemporal Landscape of the Human Brain Epitranscriptome, G5385845597, G6023573817, EAGER: Novel Computational Models and Algorithms for Mapping Link-Read Sequencing Data, G6348759291, G6375568880, A REMARKABLE ONCE-IN-A-LIFE TIME OPPORTUNITY CURRENTLY EXITS TO EVALUATE THE EFFECTS OF SPACEFLIGHT FACTORS ON THE MONOZYGOTIC TWIN ASTRONAUTS SCOTT, G6978705394, G7214279088, G7570055928, Epigenome Interactions in Complex Neurogenetic Disorders, G8795720185, G9000031237, G9000041302, G9000158279, G9000172469
OpenAlex ID: W3174330767