PT - JOURNAL ARTICLE AU - Irene M. Kaplow AU - Alyssa J. Lawler AU - Daniel E. Schäffer AU - Chaitanya Srinivasan AU - Morgan E. Wirthlin AU - BaDoi N. Phan AU - Xiaomeng Zhang AU - Kathleen Foley AU - Kavya Prasad AU - Ashley R. Brown AU - Zoonomia Consortium AU - Wynn K. Meyer AU - Andreas R. Pfenning TI - Relating enhancer genetic variation across mammals to complex phenotypes using machine learning AID - 10.1101/2022.08.26.505436 DP - 2022 Jan 01 TA - bioRxiv PG - 2022.08.26.505436 4099 - http://biorxiv.org/content/early/2022/08/26/2022.08.26.505436.short 4100 - http://biorxiv.org/content/early/2022/08/26/2022.08.26.505436.full AB - Protein-coding differences between mammals often fail to explain phenotypic diversity, suggesting involvement of enhancers, often rapidly evolving regions that regulate gene expression. Identifying associations between enhancers and phenotypes is challenging because enhancer activity is context-dependent and may be conserved without much sequence conservation. We developed TACIT (Tissue-Aware Conservation Inference Toolkit) to associate open chromatin regions (OCRs) with phenotypes using predictions in hundreds of mammalian genomes from machine learning models trained to learn tissue-specific regulatory codes. Applying TACIT for motor cortex and parvalbumin-positive interneurons to neurological phenotypes revealed dozens of new OCR-phenotype associations. Many associated OCRs were near relevant genes, including brain size-associated OCRs near genes mutated in microcephaly or macrocephaly. Our work creates a forward genomics foundation for identifying candidate enhancers associated with phenotype evolution.One Sentence Summary A new machine learning-based approach associates enhancers with the evolution of brain size and behavior across mammals.Competing Interest StatementThe authors have declared no competing interest.