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Biology subjects

Kubler, K.

Publications and source records attributed to Kubler, K..

3 recordsLinked to original sources

Endometriosis lesions are oligoclonal structures derived from the normal endometrium

Endometriosis is characterized by the presence of endometrium-like tissue outside the uterus. The origin of this ectopic tissue is debated, with leading theories including retrograde menstruation and embryonic remnants. Using somatic mutations as markers, we show that endometriosis lesions consist of unrelated clones of epithelial cells, with stromal cells being distinct, and that lesions at different body sites have different sets of clones. We observed that mutation burdens, signatures and driver landscapes are similar in cells from lesions and normal endometrium and the distribution of somatic mutations along the length of chromosomes is consistent with uterine origin. Furthermore a large-scale screen of the normal endometrium of endometriosis patients identified clones that are ancestral to endometriosis, indicating that the ectopic tissue in endometriosis originates from the normal endometrium.

genetics↗

Genome-wide mutational signatures of immunological diversification in normal lymphocytes

A lymphocyte suffers many threats to its genome, including programmed mutation during differentiation, antigen-driven proliferation and residency in diverse microenvironments. After developing protocols for single-cell lymphocyte expansions, we sequenced whole genomes from 717 normal naive and memory B and T lymphocytes and hematopoietic stem cells. Lymphocytes carried more point mutations and structural variation than stem cells, accruing at higher rates in T than B cells, attributable to both exogenous and endogenous mutational processes. Ultraviolet light exposure and other sporadic mutational processes generated hundreds to thousands of mutations in some memory lymphocytes. Memory B cells acquired, on average, 18 off-target mutations genome-wide for every one on-target IGV mutation during the germinal center reaction. Structural variation was 16-fold higher in lymphocytes than stem cells, with ~15% of deletions being attributable to off-target RAG activity. One Sentence SummaryThe mutational landscape of normal lymphocytes chronicles the off-target effects of programmed genome engineering during immunological diversification and the consequences of differentiation, proliferation and residency in diverse microenvironments.

genomics↗

A comprehensive analysis of RNA sequences reveals macroscopic somatic clonal expansion across normal tissues

Cancer genome studies have significantly advanced our knowledge of somatic mutations. However, how these mutations accumulate in normal cells and whether they promote pre-cancerous lesions remains poorly understood. Here we perform a comprehensive analysis of normal tissues by utilizing RNA sequencing data from [~]6,700 samples across 29 normal tissues collected as part of the Genotype-Tissue Expression (GTEx) project. We identify somatic mutations using a newly developed pipeline, RNA-MuTect, for calling somatic mutations directly from RNA-seq samples and their matched-normal DNA. When applied to the GTEx dataset, we detect multiple variants across different tissues and find that mutation burden is associated with both the age of the individual and tissue proliferation rate. We also detect hotspot cancer mutations that share tissue specificity with their matched cancer type. This study is the first to analyze a large number of samples across multiple normal tissues, identifying clones with genomic aberrations observed in cancer.

genomics↗