10 research outputs found

    Elevated rates of horizontal gene transfer in the industrialized human microbiome

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    Industrialization has impacted the human gut ecosystem, resulting in altered microbiome composition and diversity. Whether bacterial genomes may also adapt to the industrialization of their host populations remains largely unexplored. Here, we investigate the extent to which the rates and targets of horizontal gene transfer (HGT) vary across thousands of bacterial strains from 15 human populations spanning a range of industrialization. We show that HGTs have accumulated in the microbiome over recent host generations and that HGT occurs at high frequency within individuals. Comparison across human populations reveals that industrialized lifestyles are associated with higher HGT rates and that the functions of HGTs are related to the level of host industrialization. Our results suggest that gut bacteria continuously acquire new functionality based on host lifestyle and that high rates of HGT may be a recent development in human history linked to industrialization.Peer reviewe

    Finishing the euchromatic sequence of the human genome

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    The sequence of the human genome encodes the genetic instructions for human physiology, as well as rich information about human evolution. In 2001, the International Human Genome Sequencing Consortium reported a draft sequence of the euchromatic portion of the human genome. Since then, the international collaboration has worked to convert this draft into a genome sequence with high accuracy and nearly complete coverage. Here, we report the result of this finishing process. The current genome sequence (Build 35) contains 2.85 billion nucleotides interrupted by only 341 gaps. It covers ∼99% of the euchromatic genome and is accurate to an error rate of ∼1 event per 100,000 bases. Many of the remaining euchromatic gaps are associated with segmental duplications and will require focused work with new methods. The near-complete sequence, the first for a vertebrate, greatly improves the precision of biological analyses of the human genome including studies of gene number, birth and death. Notably, the human enome seems to encode only 20,000-25,000 protein-coding genes. The genome sequence reported here should serve as a firm foundation for biomedical research in the decades ahead

    Morphological and molecular support for Amphithrax verrucosus (H. Milne Edwards, 1832) and Amphithrax aculeatus (Herbst, 1790) (Crustacea, Decapoda, Brachyura) as valid species

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    The large degree of morphological variations, particularly amongst juveniles, has led to inconsistencies in the literature regarding the taxonomic status of Amphithrax aculeatus (Herbst, 1790) and Amphithrax verrucosus (H. Milne Edwards, 1832). As a result of recent biodiversity sampling initiatives in Barbados, West Indies, multiple specimens of Amphithrax aculeatus and A. verrucosus have been collected. This has prompted us to undertake a thorough reassessment of their morphological and molecular characteristics. Moreover, morphological differences in the carapace, antennae, chelipeds, pereopods and the male first gonopod (G1) supports A. aculeatus and A. verrucosus as separate species. Molecular phylogenetic analysis, based on newly-generated sequences of the 12S rRNA, 16S rRNA and ITS-1 genes also shows that A. verrucosus is a separate species and sister taxa to A. aculeatus. The total number of species within the genus Amphithrax is now brought to eleven. However, our molecular analysis also shows that the taxonomic placement of Amphithrax armatus (Saussure, 1853) within Amphithrax is questionable

    Morphological and molecular support for Amphithrax verrucosus (H. Milne Edwards, 1832) and Amphithrax aculeatus (Herbst, 1790) (Crustacea, Decapoda, Brachyura) as valid species

    No full text
    The large degree of morphological variations, particularly amongst juveniles, has led to inconsistencies in the literature regarding the taxonomic status of Amphithrax aculeatus (Herbst, 1790) and Amphithrax verrucosus (H. Milne Edwards, 1832). As a result of recent biodiversity sampling initiatives in Barbados, West Indies, multiple specimens of Amphithrax aculeatus and A. verrucosus have been collected. This has prompted us to undertake a thorough reassessment of their morphological and molecular characteristics. Moreover, morphological differences in the carapace, antennae, chelipeds, pereopods and the male first gonopod (G1) supports A. aculeatus and A. verrucosus as separate species. Molecular phylogenetic analysis, based on newly-generated sequences of the 12S rRNA, 16S rRNA and ITS-1 genes also shows that A. verrucosus is a separate species and sister taxa to A. aculeatus. The total number of species within the genus Amphithrax is now brought to eleven. However, our molecular analysis also shows that the taxonomic placement of Amphithrax armatus (Saussure, 1853) within Amphithrax is questionable
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