Hybridization derived novel patterns of gene expression

ongoing

Hybridization has been documented to the extent where its importance for generating evolutionary novelty can no longer be questioned. In spite of this, we lack an understanding of the evolution of regulation of gene expression in hybrids, and its role in hybridization derived novelty. Gene expression evolves in a stabilizing manner where cis(local)- and trans(distal) regulatory elements co-evolve. As hybridization breaks up co-inheritance of regulatory elements transgressive hybrid expression patterns, transcending the ranges of both parent species, may arise in spite of intermediate genome composition. I propose to leverage my finding of transgressive gene expression in a wild hybrid species and address how hybridization produces transgressive gene expression. This research will give insights into how hybridization can contribute to the arrival of the fittest, by producing novel variation that selection can act on. Objectives: 1. To determine how regulation of gene expression in hybrids can produce evolutionary novelty 2. To unravel the roles of hybridization induced transposable element-releases, alterations of methylation and larger structural variants in hybrid specific gene expression 3. To uncover the role of gene expression in avian hybrid sterility. I will use four independent hybrid lineages of the Italian sparrow and experimental F1 hybrids to achieve these ambitious goals. HybridExpress will i) Uncover how hybrid gene expression can transcend parental ranges, producing evolutionary novelty, ii) Contribute insights into how the variation selection acts on arises, iii) Increase our understanding of hybrid genotype-phenotype maps, and iv) Reveal the role of hybrid misexpression in reproductive isolation. Interdisciplinary character: This proposal will make extensive use of genomic methods and hence overlaps to some degree with the LS2 panel, but as the question addressed is evolutionary I deem the proposal best suited for evaluation by the LS8 panel.