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 ‘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: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.
Project description:Gene expression programs depend on sequence-specific DNA binding transcription factors, but the mechanisms that control the selective binding of these factors in a chromosomal and genomic context remain enigmatic. Here, we show that two master regulators of B-cell fate, namely EBF1 and RBP-jk, show variable genome-wide chromosome distribution in two related B-lymphocyte lines carrying different forms of Epstein-Barr Virus (EBV) latency. The latency-type specific EBV-encoded EBNA2 colocalized with RBP-jk and EBF1 at induced binding sites. Colocalization of EBF1, RBP-jk, and EBNA2 correlated with transcriptional activation. Conditional expression or repression of EBNA2 lead to a rapid alteration in RBP-jk and EBF1 binding. Biochemical and shRNA depletion studies provide evidence for cooperative assembly at co-occupied sites. These findings reveal that non-DNA binding cofactors can facilitate combinatorial interactions to induce new patterns of transcription factor occupancy and gene programming Examination of EBNA2/EBF1/EBP-jk binding in MutuI and LCL cell lines
