Haplotype-resolved genome assemblies are important for understanding how combinations of variants impact phenotypes. These assemblies can be created in various ways, such as use of tissues that contain single-haplotype (haploid) genomes, or by co-sequencing of parental genomes, but these approaches can be impractical in many situations. We present FALCON-Phase, which integrates long-read sequencing data and ultra-long-range Hi-C chromatin interaction data of a diploid individual to create high-quality, phased diploid genome assemblies. The method was evaluated by application to three datasets, including human, cattle, and zebra finch, for which high-quality, fully haplotype resolved assemblies were available for benchmarking. Phasing algorithm accuracy…
A fundamental tenet of multicellular eukaryotic evolution is that vertical inheritance is paramount, with natural selection acting on genetic variants transferred from parents to offspring. This lineal process means that an organism’s adaptive potential can be restricted by its evolutionary history, the amount of standing genetic variation, and its mutation rate. Lateral gene transfer (LGT) theoretically provides a mechanism to bypass many of these limitations, but the evolutionary importance and frequency of this process in multicellular eukaryotes, such as plants, remains debated. We address this issue by assembling a chromosome-level genome for the grass Alloteropsis semialata, a species surmised to…
Brassica napus (AACC, 2n = 38) is an important oilseed crop grown worldwide. However, little is known about the population evolution of this species, the genomic difference between its major genetic groups, such as European and Asian rapeseed, and the impacts of historical large-scale introgression events on this young tetraploid. In this study, we reported the de novo assembly of the genome sequences of an Asian rapeseed (B. napus), Ningyou 7, and its four progenitors and compared these genomes with other available genomic data from diverse European and Asian cultivars. Our results showed that Asian rapeseed originally derived from European rapeseed but subsequently…
The evolution and global transmission of antimicrobial resistance has been well documented in Gram-negative bacteria and healthcare-associated epidemic pathogens, often emerging from regions with heavy antimicrobial use. However, the degree to which similar processes occur with Gram-positive bacteria in the community setting is less well understood. Here, we trace the recent origins and global spread of a multidrug resistant, community-associated Staphylococcus aureus lineage from the Indian subcontinent, the Bengal Bay clone (ST772). We generated whole genome sequence data of 340 isolates from 14 countries, including the first isolates from Bangladesh and India, to reconstruct the evolutionary history and genomic epidemiology…
Here, we report the complete genome sequence of Burkholderia pseudomallei HNBP001, an epidemic strain isolated from a melioidosis patient with pneumonia in Hainan, China.Copyright © 2019 Kang et al.
High-coverage long-read sequencing of the Halobacterium salinarum type strain (91-R6) revealed a 2.17-Mb chromosome and two large plasmids (148 and 102 kb). Population heterogeneity and long repeats were observed. Strain 91-R6 and laboratory strain R1 showed 99.63% sequence identity in common chromosomal regions and only 38 strain-specific segments. This information resolves the previously uncertain relationship between type and laboratory strains.Copyright © 2019 Pfeiffer et al.
Here, we announce the complete genome sequence of Streptococcus pyogenes strain 10-85 (type emm1), isolated from a patient with streptococcal toxic shock syndrome (STSS). The strain lacks the genomic regions encoding SalR-SalK, a two-component regulatory system, and the adjacent type I restriction modification system.Copyright © 2019 Tatsuno et al.
The blood clam, Scapharca (Anadara) broughtonii, is an economically and ecologically important marine bivalve of the family Arcidae. Efforts to study their population genetics, breeding, cultivation, and stock enrichment have been somewhat hindered by the lack of a reference genome. Herein, we report the complete genome sequence of S. broughtonii, a first reference genome of the family Arcidae.A total of 75.79 Gb clean data were generated with the Pacific Biosciences and Oxford Nanopore platforms, which represented approximately 86× coverage of the S. broughtonii genome. De novo assembly of these long reads resulted in an 884.5-Mb genome, with a contig N50…
The pathogenic extended-spectrum-beta-lactamase (ESBL)-producing Escherichia coli lineage ST648 is increasingly reported from multiple origins. Our study of a large and global ST648 collection from various hosts (87 whole-genome sequences) combining core and accessory genomics with functional analyses and in vivo experiments suggests that ST648 is a nascent and generalist lineage, lacking clear phylogeographic and host association signals. By including large numbers of ST131 (n?=?107) and ST10 (n?=?96) strains for comparative genomics and phenotypic analysis, we demonstrate that the combination of multidrug resistance and high-level virulence are the hallmarks of ST648, similar to international high-risk clonal lineage ST131. Specifically, our in…
Pecan (Carya illinoinensis) and Chinese hickory (C. cathayensis) are important commercially cultivated nut trees in the genus Carya (Juglandaceae), with high nutritional value and substantial health benefits.We obtained >187.22 and 178.87 gigabases of sequence, and ~288× and 248× genome coverage, to a pecan cultivar (“Pawnee”) and a domesticated Chinese hickory landrace (ZAFU-1), respectively. The total assembly size is 651.31 megabases (Mb) for pecan and 706.43 Mb for Chinese hickory. Two genome duplication events before the divergence from walnut were found in these species. Gene family analysis highlighted key genes in biotic and abiotic tolerance, oil, polyphenols, essential amino acids, and…
Staphylococcus aureus is a significant human pathogen whose evolution and adaptation have been shaped in part by mobile genetic elements (MGEs), facilitating the global spread of extensive antimicrobial resistance. However, our understanding of the evolutionary dynamics surrounding MGEs, in particular, how changes in the structure of multidrug resistance (MDR) plasmids may influence important staphylococcal phenotypes, is incomplete. Here, we undertook a population and functional genomics study of 212 methicillin-resistant S. aureus (MRSA) sequence type 239 (ST239) isolates collected over 32?years to explore the evolution of the pSK1 family of MDR plasmids, illustrating how these plasmids have coevolved with and contributed…
The severity of environmental conditions at Earth’s frigid zones present attractive opportunities for microbial biomining due to their heightened potential as reservoirs for novel secondary metabolites. Arid soil microbiomes within the Antarctic and Arctic circles are remarkably rich in Actinobacteria and Proteobacteria, bacterial phyla known to be prolific producers of natural products. Yet the diversity of secondary metabolite genes within these cold, extreme environments remain largely unknown. Here, we employed amplicon sequencing using PacBio RS II, a third generation long-read platform, to survey over 200 soils spanning twelve east Antarctic and high Arctic sites for natural product-encoding genes, specifically targeting…
Bacteriophages, viruses that only kill specific bacteria, are receiving substantial attention as nontraditional antibacterial agents that may help alleviate the growing antibiotic resistance problem in medicine. We describe the design and preclinical development of AB-SA01, a fixed-composition bacteriophage product intended to treat Staphylococcus aureus infections. AB-SA01 contains three naturally occurring, obligately lytic myoviruses related to Staphylococcus phage K. AB-SA01 component phages have been sequenced and contain no identifiable bacterial virulence or antibiotic resistance genes. In vitro, AB-SA01 killed 94.5% of 401 clinical Staphylococcus aureus isolates, including methicillin-resistant and vancomycin-intermediate ones for a total of 95% of the 205 known multidrug-resistant…
Foodborne infections caused by lung flukes of the genus Paragonimus are a significant and widespread public health problem in tropical areas. Approximately 50 Paragonimus species have been reported to infect animals and humans, but Paragonimus westermani is responsible for the bulk of human disease. Despite their medical and economic importance, no genome sequence for any Paragonimus species is available.We sequenced and assembled the genome of P. westermani, which is among the largest of the known pathogen genomes with an estimated size of 1.1 Gb. A 922.8 Mb genome assembly was generated from Illumina and Pacific Biosciences (PacBio) sequence data, covering 84% of…
As they migrated out of Africa and into Europe and Asia, anatomically modern humans interbred with archaic hominins, such as Neanderthals and Denisovans. The result of this genetic introgression on the recipient populations has been of considerable interest, especially in cases of selection for specific archaic genetic variants. Hsieh et al. characterized adaptive structural variants and copy number variants that are likely targets of positive selection in Melanesians. Focusing on population-specific regions of the genome that carry duplicated genes and show an excess of amino acid replacements provides evidence for one of the mechanisms by which genetic novelty can arise…