is widely cultivated for medicinal, food, industrial, and recreational use, but much remains unknown regarding its genetics, including the molecular determinants of cannabinoid content. Here, we ...describe a combined physical and genetic map derived from a cross between the drug-type strain Purple Kush and the hemp variety "Finola." The map reveals that cannabinoid biosynthesis genes are generally unlinked but that aromatic prenyltransferase (
), which produces the substrate for THCA and CBDA synthases (THCAS and CBDAS), is tightly linked to a known marker for total cannabinoid content. We further identify the gene encoding CBCA synthase (
) and characterize its catalytic activity, providing insight into how cannabinoid diversity arises in cannabis.
and
(which determine the drug vs. hemp chemotype) are contained within large (>250 kb) retrotransposon-rich regions that are highly nonhomologous between drug- and hemp-type alleles and are furthermore embedded within ∼40 Mb of minimally recombining repetitive DNA. The chromosome structures are similar to those in grains such as wheat, with recombination focused in gene-rich, repeat-depleted regions near chromosome ends. The physical and genetic map should facilitate further dissection of genetic and molecular mechanisms in this commercially and medically important plant.
The coronavirus disease 2019 (COVID‐19) pandemic has sparked the rapid development of severe acute respiratory syndrome coronavirus 2 (SARS‐CoV‐2) diagnostics. However, emerging variants pose the ...risk for target dropout and false‐negative results secondary to primer/probe binding site (PBS) mismatches. The Agena MassARRAY® SARS‐CoV‐2 Panel combines reverse‐transcription polymerase chain reaction and matrix‐assisted laser desorption/ionization time‐of‐flight mass‐spectrometry to probe for five targets across N and ORF1ab genes, which provides a robust platform to accommodate PBS mismatches in divergent viruses. Herein, we utilize a deidentified data set of 1262 SARS‐CoV‐2‐positive specimens from Mount Sinai Health System (New York City) from December 2020 to April 2021 to evaluate target results and corresponding sequencing data. Overall, the level of PBS mismatches was greater in specimens with target dropout. Of specimens with N3 target dropout, 57% harbored an A28095T substitution that is highly specific for the Alpha (B.1.1.7) variant of concern. These data highlight the benefit of redundancy in target design and the potential for target performance to illuminate the dynamics of circulating SARS‐CoV‐2 variants.
Highlights
SARS‐CoV‐2 variation introduces mismatches at diagnostic primer/probe sites.
A multi‐target RT‐PCR/MALDI‐TOF assay captures emergent variants in NYC patients.
Paired sequencing data reveals the Alpha‐specific A28095T causes target dropout.
Diagnostic target performance illuminates dynamics of circulating SARS‐CoV‐2.
Cyclin-dependent kinase (Cdk) activation and RNA polymerase II transcription are linked by the Cdk7 kinase, which phosphorylates Cdks as a trimeric Cdk-activating kinase (CAK) complex, and serine 5 ...within the polymerase II (Pol II) C-terminal domain (CTD) as transcription factor TFIIH-bound CAK. However, the physiological importance of integrating these processes is not understood. Besides the Cdk7 ortholog Mcs6, fission yeast possesses a second CAK, Csk1. The two enzymes have been proposed to act redundantly to activate Cdc2. Using an improved analogue-sensitive Mcs6-as kinase, we show that Csk1 is not a relevant CAK for Cdc2. Further analyses revealed that Csk1 lacks a 20-amino-acid sequence required for its budding yeast counterpart, Cak1, to bind Cdc2. Transcriptome profiling of the Mcs6-as mutant in the presence or absence of the budding yeast Cak1 kinase, in order to uncouple the CTD kinase and CAK activities of Mcs6, revealed an unanticipated role of the CAK branch in the transcriptional control of the cluster of genes implicated in ribosome biogenesis and cell growth. The analysis of a Cdc2 CAK site mutant confirmed these data. Our data show that the Cdk7 kinase modulates transcription through its well-described RNA Pol II CTD kinase activity and also through the Cdc2-activating kinase activity.
The coronavirus disease‐2019 (COVID‐19) pandemic is still challenging public health systems worldwide, particularly with the emergence of novel SARS‐CoV‐2 variants with mutations that increase their ...transmissibility and immune escape. This is the case of the variant of concern Omicron that rapidly spread globally. Here, using epidemiological and genomic data we compared the situations in South Africa as the epicenter of emergence, United Kingdom, and with particular interest New York City. This rapid global dispersal from the place of first report reemphasizes the high transmissibility of Omicron, which needed only two weeks to become dominant in the United Kingdom and New York City. Our analyses suggest that as SARS‐CoV‐2 continues to evolve, global authorities must prioritize equity in vaccine access and continued genomic surveillance. Future studies are still needed to fully unveil the biological properties of Omicron, but what is certain is that vaccination, large‐scale testing, and infection prevention efforts are the greatest arsenal against the COVID‐19 pandemic.
Viruses are obligate parasites and thus require the machinery of the host cell to replicate. Inhibition of host factors co-opted during active infection is a strategy hosts use to suppress viral ...replication and a potential pan-antiviral therapy. To define the cellular proteins and processes required for a virus during infection is thus crucial to understanding the mechanisms of virally induced disease. In this report, we generated fully infectious tagged influenza viruses and used infection-based proteomics to identify pivotal arms of cellular signaling required for influenza virus growth and infectivity. Using mathematical modeling and genetic and pharmacologic approaches, we revealed that modulation of Sec61-mediated cotranslational translocation selectively impaired glycoprotein proteostasis of influenza as well as HIV and dengue viruses and led to inhibition of viral growth and infectivity. Thus, by studying virus-human protein-protein interactions in the context of active replication, we have identified targetable host factors for broad-spectrum antiviral therapies.
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•Generated replication-competent, tagged influenza viruses•Constructed human-influenza interactome network during an infection•Mathematical modeling revealed host targets for pan-viral inhibition•Sec61 inhibition alters viral proteostasis and suppresses viral replication
Viruses are obligate parasites dependent on the host cell machinery. Using infection-based proteomics, biochemistry, and mathematical modeling, Marazzi and colleagues reveal that targeting host factors controlling essential cellular functions can provide broad-spectrum antiviral effects. Loss-of-function and chemical inhibition of one such factor, Sec61, inhibited influenza, HIV, and dengue virus replication.
...we demonstrate that conclusions very similar to those of our original study are reached with a dataset with far greater read depth, obtained by strand-specific sequencing of rRNA-depleted total ...RNA from a single cell type. ...the mechanisms that control the positions of initiation and termination of Pol II transcription, as well as RNA processing, are imperfect, such that low-level background transcripts from both physiologically relevant and non-canonical sites arise 4-6.
We report the spillover of highly pathogenic avian influenza A(H5N1) into marine mammals in the northeastern United States, coincident with H5N1 in sympatric wild birds. Our data indicate monitoring ...both wild coastal birds and marine mammals will be critical to determine pandemic potential of influenza A viruses.
Here, we developed hCK, a Madin-Darby canine kidney (MDCK) cell line that expresses high levels of human influenza virus receptors and low levels of avian virus receptors. hCK cells supported human ...A/H3N2 influenza virus isolation and growth much more effectively than conventional MDCK or human virus receptor-overexpressing (AX4) cells. A/H3N2 viruses propagated in hCK cells also maintained higher genetic stability than those propagated in MDCK and AX4 cells.
Gametes are among the most highly specialized cells produced during development. Although gametogenesis culminates in transcriptional quiescence in plants and animals, regulatory mechanisms ...controlling this are unknown. Here, we confirm that gamete differentiation in the single-celled yeast Saccharomyces cerevisiae is accompanied by global transcriptional shutoff following the completion of meiosis. We show that Jhd2, a highly conserved JARID1-family histone H3K4 demethylase, activates protein-coding gene transcription in opposition to this programmed transcriptional shutoff, sustaining the period of productive transcription during spore differentiation. Moreover, using genome-wide nucleosome, H3K4me, and transcript mapping experiments, we demonstrate that JHD2 globally represses intergenic noncoding transcription during this period. The widespread transcriptional defects of JHD2 mutants are associated with precocious differentiation and the production of stress-sensitive spores, demonstrating that Jhd2 regulation of the global postmeiotic transcriptional program is critical for the production of healthy meiotic progeny.
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► Jhd2 globally demethylates H3K4 at intergenic regions during yeast sporulation ► JHD2 represses interfering intergenic transcription globally in postmeiotic cells ► JHD2 represses nucleosome accumulation at NDRs during sporulation ► JHD2 mutants produce prematurely formed gametes that are stress sensitive
JARID histone H3K4 demethylases control a balance of differentiation versus pluripotency and drug susceptibility in normal and cancer stem cells, respectively. Xu et al. show that in budding yeast, the JARID demethylase Jhd2 is a global attenuator of noncoding transcription that sustains genic transcriptional activity and thereby delays gamete differentiation.
Although transcriptional and posttranscriptional events are detected in RNA-Seq data from second-generation sequencing, full-length mRNA isoforms are not captured. On the other hand, third-generation ...sequencing, which yields much longer reads, has current limitations of lower raw accuracy and throughput. Here, we combine second-generation sequencing and third-generation sequencing with a custom-designed method for isoform identification and quantification to generate a high-confidence isoform dataset for human embryonic stem cells (hESCs). We report 8,084 RefSeq-annotated isoforms detected as full-length and an additional 5,459 isoforms predicted through statistical inference. Over one-third of these are novel isoforms, including 273 RNAs from gene loci that have not previously been identified. Further characterization of the novel loci indicates that a subset is expressed in pluripotent cells but not in diverse fetal and adult tissues; moreover, their reduced expression perturbs the network of pluripotency-associated genes. Results suggest that gene identification, even in well-characterized human cell lines and tissues, is likely far from complete.
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