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Biomedical subjects

Etienne Patin

Publications and source records attributed to Etienne Patin.

2 recordsLinked to original sources

eQTM (expression quantitative trait methylation) Atlas: a comprehensive resource of over 11 million DNA methylation-gene expression associations through across 11 tissues and 4 diseases.

MOTIVATION: Epigenome-wide association studies (EWAS) have identified numerous DNA methylation (DNAm) CpG sites associated with complex traits and diseases, but interpretation of those CpG sites remains challenging because in EWAS, CpGs are mostly linked to nearby genes based only on genomic proximity. Expression quantitative trait methylation (eQTM) analyses connect DNAm CpGs with statistically associated gene expression levels. However, a comprehensive, searchable resource integrating eQTMs across diverse tissues and disease contexts has been lacking. RESULTS: We developed the eQTM Atlas, a web-based resource that manually curates more than 11 million DNAm-gene expression associations from eight cohorts, covering 11 tissue types, four broad disease contexts, 173,886 unique CpG probes and 20,231 unique genes. The Atlas supports gene- or CpG- searches by tissue or disease type and finding associated CpG or genes, visualization of cis- and trans-eQTMs through genome browser, heatmap interfaces across various tissues, and cohort-level data downloads. By integrating eQTM results with EWAS resources, the eQTM Atlas enables users to connect disease- or trait-associated CpGs to statistically associated genes rather than relying solely on proximity-based gene annotation, supporting functional interpretation of EWAS findings and generation of disease-specific regulatory hypotheses. AVAILABILITY AND IMPLEMENTATION: The eQTM Atlas is freely available at https://shiny.crc.pitt.edu/eqtm_browser/. The web interface is implemented in R Shiny and hosted through the University of Pittsburgh Center for Research Computing (CRC). Source code is available at https://github.com/ads303/eQTM-Atlas.

DNA methylation

Nested Admixture During and After the Trans-Atlantic Slave Trade on the Island of São Tomé.

Human genetic admixture, involving the contact between two or more previously isolated populations, can be a complex process influenced by social dynamics. In this study, we aim to reconstruct complex admixture histories in São Tomé, an island in the Gulf of Guinea where the Portuguese established one of the first plantation-based slave societies. Since the 15th century, migration waves from Africa and Europe, slavery, marooning, and indentured labour led to profound demographic shifts and social stratification on the island. Examining 2.5 million SNPs newly genotyped in 96 São Toméans, we observed patterns of genetic differentiation that were more complex than those of other populations descended from enslaved Africans on either side of the Atlantic. Using local ancestry inference and Identical-by-Descent methods, we identified five genetic clusters in São Tomé and reconstructed shared ancestries between each cluster and 70 African and European population samples, including an extensive sample from the Cabo Verde archipelago. Our findings align with historical records, retracing the major slave trade routes and labour-driven migrations after the abolition of slavery. We also identified gene flow between recently admixed groups that were previously isolated on the island. We call this process, creating multiple layers of genetic ancestry in admixed genomes, nested admixture. We suggest that changing social structures in São Tomé transformed the genetic structure of its population and influenced the admixture process. This study demonstrates how successive admixture and isolation events during and after the Trans-Atlantic Slave Trade shaped extant genetic diversity patterns at local scale in Africa.

Humans