Polyploidization has provided much genetic variation for plant adaptive evolution,
but the mechanisms by which the molecular evolution of polyploid genomes establishes
genetic architecture underlying species differentiation are unclear. Brassica
is an ideal model to increase knowledge of polyploid evolution. Here we describe a
draft genome sequence of Brassica oleracea, comparing it with that of its
sister species B. rapa to reveal numerous chromosome rearrangements and
asymmetrical gene loss in duplicated genomic blocks, asymmetrical amplification of
transposable elements, differential gene co-retention for specific pathways and
variation in gene expression, including alternative splicing, among a large number
of paralogous and orthologous genes. Genes related to the production of anticancer
phytochemicals and morphological variations illustrate consequences of genome
duplication and gene divergence, imparting biochemical and morphological variation
to B. oleracea. This study provides insights into Brassica genome
evolution and will underpin research into the many important crops in this
genus.
This study suggests that humidifier disinfectant inhalation causes an idiopathic type of chILD that is characterized by spontaneous air leak, rapid progression, lack of response to treatment, and high mortality. Further safety studies must be performed on common environmental compounds, particularly those that enter the human body by an unusual route.
Summary
Panax ginseng C. A. Meyer, reputed as the king of medicinal herbs, has slow growth, long generation time, low seed production and complicated genome structure that hamper its study. Here, we unveil the genomic architecture of tetraploid P. ginseng by de novo genome assembly, representing 2.98 Gbp with 59 352 annotated genes. Resequencing data indicated that diploid Panax species diverged in association with global warming in Southern Asia, and two North American species evolved via two intercontinental migrations. Two whole genome duplications (WGD) occurred in the family Araliaceae (including Panax) after divergence with the Apiaceae, the more recent one contributing to the ability of P. ginseng to overwinter, enabling it to spread broadly through the Northern Hemisphere. Functional and evolutionary analyses suggest that production of pharmacologically important dammarane‐type ginsenosides originated in Panax and are produced largely in shoot tissues and transported to roots; that newly evolved P. ginseng fatty acid desaturases increase freezing tolerance; and that unprecedented retention of chlorophyll a/b binding protein genes enables efficient photosynthesis under low light. A genome‐scale metabolic network provides a holistic view of Panax ginsenoside biosynthesis. This study provides valuable resources for improving medicinal values of ginseng either through genomics‐assisted breeding or metabolic engineering.
PurposeAlthough anaphylaxis is recognized as an important, life-threatening condition, data are limited regarding its triggers in different age groups. We aimed to identify anaphylaxis triggers by age in Korean children.MethodsWe performed a retrospective review of medical records for children diagnosed with anaphylaxis between 2009 and 2013 in 23 secondary or tertiary hospitals in South Korea.ResultsA total of 991 cases (mean age=5.89±5.24) were reported, with 63.9% involving patients younger than 6 years of age and 66% involving male children. Food was the most common anaphylaxis trigger (74.7%), followed by drugs and radiocontrast media (10.7%), idiopathic factors (9.2%), and exercise (3.6%). The most common food allergen was milk (28.4%), followed by egg white (13.6%), walnut (8.0%), wheat (7.2%), buckwheat (6.5%), and peanut (6.2%). Milk and seafood were the most common anaphylaxis triggers in young and older children, respectively. Drug-triggered anaphylaxis was observed more frequently with increasing age, with antibiotics (34.9%) and nonsteroidal anti-inflammatory drugs (17.9%) being the most common causes.ConclusionsThe most common anaphylaxis trigger in Korean children was food. Data on these triggers show that their relative frequency may vary by age.
SUMMARYGinseng (Panax ginseng) is a famous medicinal herb, but the composition and structure of its genome are largely unknown. Here we characterized the major repeat components and inspected their distribution in the ginseng genome. By analyzing three repeat-rich bacterial artificial chromosome (BAC) sequences from ginseng, we identified complex insertion patterns of 34 long terminal repeat retrotransposons (LTR-RTs) and 11 LTR-RT derivatives accounting for more than 80% of the BAC sequences. The LTR-RTs were classified into three Ty3/gypsy (PgDel, PgTat and PgAthila) and two Ty1/Copia (PgTork and PgOryco) families. Mapping of 30-Gbp Illumina whole-genome shotgun reads to the BAC sequences revealed that these five LTR-RT families occupy at least 34% of the ginseng genome. The Ty3/Gypsy families were predominant, comprising 74 and 33% of the BAC sequences and the genome, respectively. In particular, the PgDel family accounted for 29% of the genome and presumably played major roles in enlargement of the size of the ginseng genome. Fluorescence in situ hybridization (FISH) revealed that the PgDel1 elements are distributed throughout the chromosomes along dispersed heterochromatic regions except for ribosomal DNA blocks. The intensity of the PgDel2 FISH signals was biased toward 24 out of 48 chromosomes. Unique gene probes showed two pairs of signals with different locations, one pair in subtelomeric regions on PgDel2-rich chromosomes and the other in interstitial regions on PgDel2-poor chromosomes, demonstrating allotetraploidy in ginseng. Our findings promote understanding of the evolution of the ginseng genome and of that of related species in the Araliaceae.
We have fabricated electrically conductive, optically transparent, and mechanically strong shape-memory polyurethane film by incorporating photochemically surface-modified multiwalled carbon nanotubes (MWNTs). The oxygen functional groups on the sidewall of the MWNTs, created by vacuum ultraviolet light, provide reactive sites to bind strongly with polyurethane. The homogeneous dispersion of MWNTs is confirmed by the optical signals coming from the innermost tube (ca. 0.9 nm) of the MWNTs, not from isolated single walled carbon nanotubes. The optimally introduced functional groups as well as the judicious selection of organic solvent, both for dispersing MWNTs homogeneously and dissolving the polymer completely, are critical to fabricate high functional polyurethane film.
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