Project description:To characterize the genetic basis of hybrid male sterility in detail, we used a systems genetics approach, integrating mapping of gene expression traits with sterility phenotypes and QTL. We measured genome-wide testis expression in 305 male F2s from a cross between wild-derived inbred strains of M. musculus musculus and M. m. domesticus. We identified several thousand cis- and trans-acting QTL contributing to expression variation (eQTL). Many trans eQTL cluster into eleven ‘hotspots,’ seven of which co-localize with QTL for sterility phenotypes identified in the cross. The number and clustering of trans eQTL - but not cis eQTL - were substantially lower when mapping was restricted to a ‘fertile’ subset of mice, providing evidence that trans eQTL hotspots are related to sterility. Functional annotation of transcripts with eQTL provides insights into the biological processes disrupted by sterility loci and guides prioritization of candidate genes. Using a conditional mapping approach, we identified eQTL dependent on interactions between loci, revealing a complex system of epistasis. Our results illuminate established patterns, including the role of the X chromosome in hybrid sterility.
Project description:We collected whole genome testis expression data from hybrid zone mice. We integrated GWAS mapping of testis expression traits and low testis weight to gain insight into the genetic basis of hybrid male sterility.
Project description:To characterize the genetic basis of hybrid male sterility in detail, we used a systems genetics approach, integrating mapping of gene expression traits with sterility phenotypes and QTL. We measured genome-wide testis expression in 305 male F2s from a cross between wild-derived inbred strains of M. musculus musculus and M. m. domesticus. We identified several thousand cis- and trans-acting QTL contributing to expression variation (eQTL). Many trans eQTL cluster into eleven M-bM-^@M-^Xhotspots,M-bM-^@M-^Y seven of which co-localize with QTL for sterility phenotypes identified in the cross. The number and clustering of trans eQTL - but not cis eQTL - were substantially lower when mapping was restricted to a M-bM-^@M-^XfertileM-bM-^@M-^Y subset of mice, providing evidence that trans eQTL hotspots are related to sterility. Functional annotation of transcripts with eQTL provides insights into the biological processes disrupted by sterility loci and guides prioritization of candidate genes. Using a conditional mapping approach, we identified eQTL dependent on interactions between loci, revealing a complex system of epistasis. Our results illuminate established patterns, including the role of the X chromosome in hybrid sterility. Gene expression was measured in whole testis in males aged 70(M-BM-15) days. Samples include 294 WSB/EiJ x PWD/PhJ F2s, 11 PWD/PhJ x WSB/EiJ F2s, 8 WSB/EiJ, 8 PWD/PhJ, 6 PWD/PhJ x WSB/EiJ F1s and 4 WSB/EiJ x PWD/PhJ F1s.
Project description:R-loop remodeling dynamically regulates chromatin states and gene expression; however, its exploitation by cancer to sustain self-renewal and malignancy remains poorly understood. Here, we found that glioblastoma (GBM) stem cells (GSCs) display highly active R-loops compared to differentiated tumor progeny and neural stem cells (NSCs). Genome-wide mapping by R-loop RNA chromatin immunoprecipitation sequencing (RR-ChIP-seq) revealed cell-specific enrichment and spatial accumulation of R-loops at promoter-proximal regions in GSCs, correlating with active transcription and open chromatin states. We profiled R-loop interactomes and identified N-Acetyltransferase 10 (NAT10), an RNA N4-acetylcytidine (ac4C)-modifying enzyme, as a high-affinity R-loop-binding protein in GSCs. Driven by transcriptional activation via OLIG1, NAT10 was overexpressed in GSCs. ac4C-specific RNA immunoprecipitation sequencing (ac4C-RIP-seq) on R-loop RNA revealed genome-wide mapping of ac4C-modified R-loops with abundant ac4C-modified R-loops that regulated the genome. NAT10 catalyzed widespread ac4C deposition on the RNA stand of R-loops, stabilizing promoter-associated R-loops, and facilitating open chromatin to sustain self-renewal through core stemness regulators, including transcription factor EGR1. NAT10 knockdown suppressed proliferation and maintenance in vitro and attenuated tumor growth in vivo. Pharmacological inhibition of NAT10/ac4C-modified R-loops using the small-molecule inhibitor remodelin phenocopied NAT10 genetic targeting, demonstrating therapeutic promise for targeting cancer.
Project description:We collected whole genome testis expression data from hybrid zone mice. We integrated GWAS mapping of testis expression traits and low testis weight to gain insight into the genetic basis of hybrid male sterility. Gene expression was measured in whole testis from males aged 62-86 days. Samples include 190 first generation lab-bred male offspring of wild-caught mice from the Mus musculus musculus - M. m. domesticus hybrid zone.
Project description:Genome wide expression profiling to determine the overlap of Affymetrix-signals with SOLID sequencing RNA was extracted using the Qiagen RNeasy kit following the manufacturers guidelines, arrays were prepared and hybridized following the Affymetrix protocol.