Project description:Encoded in the hundreds by the human genome, KRAB-containing zinc finger proteins (KRAB-ZFPs) constitute a rapidly evolving family of transcription factors with largely undefined functions. Here, by a combination of phylogenetic and genomic approaches, we retrace the evolutionary history of KRAB-ZFP genes and define the genomic targets of their human products. Through in silico analysis of 207 vertebrate genomes and chromatin immunoprecipitation / deep sequencing characterization of 257 human KRAB-ZFPs, we identify the root of the family in an early Devonian ancestor of tetrapods, describe its diversity amongst these species, and reveal that the majority of its human members primarily recognize transposable elements. Furthermore, by dissecting the timeline and modalities of interactions between human KRAB-ZFPs and their targets, we provide evidence strongly suggesting that these proteins, rather than just engaged in an evolutionary arms race against transposable elements, exploit these invaders as regulatory platforms for the benefit of the host.
2017-03-06 | GSE78099 | GEO
Project description:Chromosome-level Assemblies of Three Salmonid Species Reveal Their Evolutionary History
Project description:Evolutionary studies are often limited by missing data that are critical to understanding the history of selection. Selection experiments, which reproduce rapid evolution under controlled conditions, are excellent tools to study how genomes evolve under selection. Here we present a genomic dissection of the Longshanks selection experiment, in which mice were selectively bred over 20 generations for longer tibiae relative to body mass, resulting in 13% longer tibiae in two replicates. We synthesized evolutionary theory, genome sequences and molecular genetics to understand the selection response and found that it involved both polygenic adaptation and discrete loci of major effect, with the strongest loci likely to be selected in parallel between replicates. We show that selection may favor de-repression of bone growth through inactivating two limb enhancers of an inhibitor, Nkx3-2. Our integrative genomic analyses thus show that it is possible to connect individual base-pair changes to the overall selection response.