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.
Project description:Venoms and the toxins they contain represent molecular adaptations that have evolved on numerous occasions throughout the animal kingdom. However, the processes that shape venom protein evolution are poorly understood because of the scarcity of whole genome data available for comparative analyses of venomous species. Here, we perform a broad comparative toxicogenomic analysis to gain insight into the genomic mechanisms of venom evolution in robber flies (Asilidae). We first sequenced a high-quality draft genome of the hymenopteran hunting robber fly Dasypogon diadema, and analysed its venom by a combined proteotranscriptomic approach, and compared our results to recently described robber fly venoms to assess the general composition and major components of asilid venom. We then applied a comparative genomics approach, based on one additional asilid genome, ten high-quality dipteran genomes, and two lepidopteran outgroup-genomes, to reveal the evolutionary mechanisms and origins of identified venom proteins in robber flies. While some venom proteins were identified in the non-asilid genomes, several of the identified highly expressed venom proteins appear to be unique to robber flies. Our results reveal that the venom of D. diadema likely evolves in a multimodal fashion comprising 1) neofunctionalization after gene duplication, 2) expression-dependent co-option of proteins and 3) asilid lineage-specific orphan genes with enigmatic origin. The role of such orphan genes is currently being disputed in evolutionary genomics, but has not yet discussed in the context of toxin evolution. Our results display an unexpected dynamic venom evolution in asilid insects, which contrasts the findings of the only other insect toxicogenomic evolutionary analysis, in parasitoid wasps (Hymenoptera), were toxin evolution is dominated by single gene co-option.
2019-06-13 | PXD013358 | Pride
Project description:Evolutionary history of Iberodes